**Supplemental abstracts, AChEi briefing:**

# Citations 373-705

This provides supplemental citations in three richly cited areas:

**A. Pyridostigmine growth hormone response**

**B. Cognitive effects of AChEi and other cholinergic agonists in
Alzheimer\'s and other conditions; or use of AChEi in Alzheimer\'s**

**C. AChE changes in CSF in Alzheimer\'s**

373\. Andersen, M., *et al.*, *The effect of short-term cortisol changes
on growth hormone responses to the
pyridostigmine-growth-hormone-releasing-hormone test in healthy adults
and patients with suspected growth hormone deficiency.* Clin Endocrinol
(Oxf), 1998. 49(2): p. 241-9. BACKGROUND AND AIMS: The interaction
between cortisol and growth hormone (GH)-levels may significantly
influence GH-responses to a stimulation test. In order to systematically
analyse the interaction in a paired design, it is necessary to use a
test, which has been proven safe and reliable such as the
pyridostigmine-growth-hormone-releasing-hormone (PD-GHRH) test. Three
groups of subjects with a different GH-secretory capacity were included.
STUDY A: Eight healthy adults were tested seven times, once with placebo
throughout the examination and six times with the PD-GHRH test following
no glucocorticoid pretreatment, pretreatment with hydrocortisone (HC)
(30 mg/day and 80 mg/day for 1 and 3 days) or pretreatment with 15 mg
prednisolone for 1 day. HC (80 mg/day for 1 day) in combination with PD
significantly stimulated GH-levels compared to PD alone, 18.9 mU/l +/-
6.1 vs 3.0 mU/l +/- 0.8 (P \< 0.05). However, peak GH-responses to PD in
combination with GHRH were reduced during HC (80 mg/day for 1 day)
compared to no glucocorticoid pretreatment in all healthy adults.
Conventional HC therapy (30 mg/day for 1 and 3 days) did not
significantly affect peak GH-responses. STUDY B: 16 patients with
suspected GH-deficiency (GHD) (seven with known ACTH-deficiency and nine
with an intact pituitary-adrenal axis) were tested five times with the
PD-GHRH test following no pretreatment or pretreatment with HC (30
mg/day and 80 mg/day for 1 and 3 days). Peak GH-responses were not
significantly affected by conventional HC therapy (30 mg/day for 1 and 3
days). However, peak GH-responses to PD in combination with GHRH were
reduced during HC (80 mg/day for 1 day) compared to no glucocorticoid
pretreatment in all patients. Short-term hypocortisolism did not
significantly affect peak GH-responses. CONCLUSION: The GH-responses to
a PD-GHRH test were reduced in all individuals during acute
stress-appropriate cortisol levels and the percentage reduction in
GH-levels was independent of the GH-secretory capacity. Clinically, we
found that peak GH-responses were not significantly affected by a short
break in conventional HC therapy nor by conventional HC therapy itself.
However, our results also demonstrated that a GH-stimulation test should
not be performed on patients, suffering from acute stress.

374\. Arvat, E., *et al.*, *Pyridostigmine potentiates growth hormone
(GH)-releasing hormone-induced GH release in both men and women.* J Clin
Endocrinol Metab, 1993. 76(2): p. 374-7. It has been recently reported
that pyridostigmine (PD), an indirect cholinergic agonist, probably
acting via inhibition of hypothalamic somatostatin, potentiates the
GH-releasing hormone (GHRH)-induced GH rise in men, but not in women.
The aim of this study was to verify the sex-related, if any, GH response
to GHRH (1 microgram/kg, i.v., as a bolus) both alone and preceded by
two different doses of PD (120 mg, group A, and 60 mg, group B, given
orally 60 min before GHRH) in a large group of volunteers (36 women,
aged 18-35 yr, and 48 men, aged 18-35 yrs). In group A, 120 mg oral PD
potentiated the GH response to GHRH in both men \[area under the curve
(AUC), 2579.3 +/- 264.5 vs. 806.2 +/- 99.7 micrograms/L.h; P \<
0.00001\] and women (AUC, 2273.2 +/- 248.7 vs. 792.6 +/- 72.7
micrograms/L.h; P \< 0.00001). Similarly, in the group B, 60 mg oral PD
potentiated the GH response to GHRH in both men (AUC, 1929.6 +/- 157.2
vs. 568.2 +/- 81.3 micrograms/L.h; P \< 0.01) and in women (AUC, 1655.9
+/- 146.9 vs. 738.2 +/- 105.7 micrograms/L.h; P \< 0.01). The GH
responses to GHRH, both alone and after 120 and 60 mg oral PD, did not
significantly differ in men and women. No sex-related difference was
observed in the cholinergic side-effects (mild abdominal pain and muscle
fasciculations) that occurred in nearly 30% of the subjects. In
conclusion, our results clearly show that there is no sex-related
difference in the potentiating effect of PD on GHRH-induced GH release,
ruling out the suggestion that women have increased cholinergic
activity, leading to reduced somatostatinergic tone.

375\. Arvat, E., *et al.*, *The enhancing effect of pyridostigmine on
the GH response to GHRH undergoes an accelerated age-related reduction
in Down syndrome.* Dementia, 1996. 7(5): p. 288-92. Cholinergic agonists
are known to potentiate GHRH-induced GH secretion, probably acting via
inhibition of hypothalamic somatostatin release. Their effect is reduced
in aging and in patients with Alzheimer\'s disease. This may be the
consequence of age-related cholinergic impairment, which, in turn, could
cause somatostatinergic hyperactivity leading to GH hyposecretion. As in
Down syndrome (DS) neural alterations have been reported similar to
those in aging, including cholinergic impairment, we verified the GH
response to GHRH (1 microgram/kg i.v. at 0 min) alone or combined with
pyridostigmine (PD), a cholinesterase inhibitor (60 and 120 mg,
respectively, in children and adults, orally at -60 min) in 15 DS
children (13.5 +/- 0.6 years) and in 11 DS young adults (24.0 +/- 1.2
years). Fifteen normal children (11.9 +/- 0.5 years), 15 normal adults
(27.3 +/- 0.9 years) and 16 normal elderly (76.3 +/- 1.5 years) were
studied as controls. IGF-I levels showed an age-related reduction both
in DS (children vs. adults, mean +/- SEM:354.8 +/- 44.9 vs. 204.4 +/-
29.4 micrograms/l, p \< 0.02) and in controls (normal children vs.
normal adults vs. normal elderly:281.4 +/- 36.3 vs. 175.4 +/- 11.2 vs.
72.5 +/- 6.6 micrograms/l, p \< 0.001). The GH response to GHRH in DS
children was higher than in DS adults (areas under curve: 1,197.6 +/-
241.5 vs. 434.4 +/- 83.3 micrograms/l/h, p \< 0.01). On the other hand,
in normal subjects the GHRH-induced GH rise was similar in children and
adults (1,056.2 +/- 128.4 vs. 800.8 +/- 124.5 micrograms/l/h) and both
were higher than that in elderly subjects (296.0 +/- 61.0
micrograms/l/h, p \< 0.001). PD enhanced the GH response to GHRH both in
DS and in normal subjects (p \< 0.005). The GH response to PD+GHRH was
lower in DS adults than in DS children (1,068.1 +/- 145.7 vs. 1,897.4
+/- 198.8 micrograms/l/h, p \< 0.001) as well as in normal elderly
subjects with respect to that in normal children and normal adults
(832.3 +/- 144.7 vs. 2,172.1 +/- 156.1 and 2,347.6 +/- 322.4
micrograms/l/h, respectively, p \< 0.001). The GH response to GHRH alone
or combined with PD in DS adults was lower (p \< 0.01) than that in
normal adults and similar to that in normal elderly subjects. In
conclusion, the present data demonstrate that the stimulated GH
secretion in DS undergoes an accelerated age-related reduction. They
also suggest the existence of a precocious impairment of central
cholinergic activity in DS, which, in turn, could cause
somatostatinergic hyperactivity and reduced GH secretion.

376\. Arvat, E., *et al.*, *Low hexarelin dose and pyridostigmine have
additive effect and potentiate to the same extent the GHRH-induced GH
response in man.* Clin Endocrinol (Oxf), 1997. 47(4): p. 495-500.
OBJECTIVES: Hexarelin (HEX) is a synthetic hexapeptide belonging to the
growth hormone-releasing peptide (GHRP) family. The exact mechanism
underlying the strong GH-releasing activity of GHRPs is still unclear,
though it has been shown that they act both at the pituitary and the
hypothalamic level, where they have specific receptors. To clarify the
influence of the cholinergic system on the GH-releasing activity of
GHRPs in man, we investigated the effects of pyridostigmine, a
cholinergic agonist which stimulates GH secretion by inhibiting
somatostatin release, on the GH response to various HEX doses. DESIGN:
We studied the GH release induced by various HEX doses (0.25, 0.5 and
2.0 micrograms/kg i.v.) and pyridostigmine (PD, 120 mg po), both alone
and coadministered. The interactions between the lowest HEX dose or PD
and the maximally effective GHRH dose (1.0 microgram/kg i.v.) were also
studied. SUBJECTS: Six normal male volunteers, aged 24-30 years, were
studied. MEASUREMENTS: Serum GH was measured in duplicate by
immunoradiometric assay. RESULTS: The GH response to HEX administration
was dose-dependent. In fact, the GH response to 0.25 microgram/kg HEX
(AUC, mean +/- SEM: 816.4 (235.6 mU/l/120 min) was lower, although not
significantly, than that to 0.5 microgram/kg HEX (2154.6 +/- 491.6
mU/l/120 min), which, in turn, was lower (p \< 0.05) than that after 2.0
micrograms/kg HEX (4819.2 +/- 668.0 mU/l/120 min). The GH rise after
GHRH (1299.2 +/- 222.8 mU/l/120 min) was lower (P \< 0.05) than that
after 2.0 micrograms/kg HEX, but not different from the responses to
either 0.25 or 0.5 microgram/kg HEX. PD induced a significant GH rise
(559.0 +/- 129.8 mU/l/120 min, P \< 0.05 vs saline), similar to that
after 0.25 microgram/kg HEX, and lower than those after both 0.5 and 2.0
micrograms/kg HEX (P \< 0.05 and p \< 0.01, respectively) and GHRH (p \<
0.05). PD pretreatment enhanced the GH response to the lowest HEX dose
(1961.4 +/- 253.8 mU/l/120 min, p \< 0.05) in an additive way, but
failed to modify the GH response to either 0.5 or 2.0 micrograms/kg HEX
(2753.6 +/- 444.6 and 5179.0 +/- 770.8 mU/l/120 min, respectively).
Notably, the GH response to 0.25 microgram/kg HEX + PD was still lower
(P \< 0.05) than that to 2.0 micrograms/kg HEX. PD pretreatment as well
as 0.25 microgram/kg HEX truly potentiated the GH response to GHRH to
the same extent (4926.6 +/- 912.8 mU/l/120 min, p \< 0.05 and 5958.8 +/-
750.0 mU/l/120 min, p \< 0.05 respectively). The GH responses to PD +
GHRH and 0.25 microgram/kg HEX + GHRH were similar to that after 2.0
micrograms/kg HEX alone. CONCLUSIONS: Our results demonstrate that
pyridostigmine is able to enhance the GH response only to a very low
dose Hexarelin which, in turn, potentiates the GHRH-induced GH rise to
the same extent as pyridostigmine. As there is evidence that GHRPs do
not inhibit hypothalamic somatostatin release, these findings are
consistent with the hypothesis that they act by antagonizing
somatostatin activity and/or through unknown factors. On the other hand,
though there is evidence showing that GHRH activity is needed for GHRP
action, our findings indicate that GHRPs act, at least partially,
independently of GHRH.

377\. Barbarino, A., *et al.*, *Sexual dimorphism of pyridostigmine
potentiation of growth hormone (GH)-releasing hormone-induced GH release
in humans.* J Clin Endocrinol Metab, 1991. 73(1): p. 75-8. Sex
differences in the neuroregulation of GH secretion are not now known in
humans. To investigate whether activation of cholinergic tone by
pyridostigmine could cause a sex-related difference in the pituitary
responsiveness to GH-releasing hormone (GHRH), we have studied the GH
response to GHRH in 16 normal subjects (8 men and 8 women) tested after
oral placebo or different doses of pyridostigmine (30, 60, and 120 mg).
Each subject presented a normal response after iv administration of 50
micrograms GHRH and placebo. In men each dose of pyridostigmine induced
a significant increase in the GH response to GHRH, as assessed by both
the maximal GH peak and the area under GH curve. In women, on the
contrary, the GH response to GHRH was not potentiated by pretreatment
with pyridostigmine at any given dose. Only five female subjects were
tested with 120 mg pyridostigmine because of the severe side-effects of
the drug at this dosage. Our present data strongly suggest that in
humans there is a sex-related difference in the neuroregulation of GH
secretion and this is probably expressed through a different cholinergic
tone.

378\. Beccaria, L., *et al.*, *Impairment of growth hormone
responsiveness to growth hormone releasing hormone and pyridostigmine in
patients affected by Prader-Labhardt-Willi syndrome.* J Endocrinol
Invest, 1996. 19(10): p. 687-92. In order to evaluate the impairment of
GH response in patients affected by Prader-Labhardt-Willi (PLW)
syndrome, in 18 patients we studied GH response to clonidine and to
GHRH + pyridostigmine, a cholinergic drug which enhances GHRH induced GH
responsiveness in obese patients. After clonidine GH response was
abnormal in 14/18 subjects (mean GH peak: 4.1 +/- 1.3 micrograms/l; area
under curve: 208.1 +/- 74.2 micrograms/l.h) while all but 5 patients
showed an inadequate GH response to GHRH + pyridostigmine (mean GH peak:
13.4 +/- 2.5 micrograms/l; area under curve: 903.4 +/- 171.0
micrograms/l.h). However, in the three patients with low adiposity
index, GH response to GHRH + pyridostigmine was significantly higher
than that observed in fatter subjects. In addition, GH response to
GHRH + pyridostigmine was negatively correlated to age and adiposity
index. In conclusion, our data are consistent with the hypothesis of the
existence of a complex derangement of GH neuroendocrine regulation in
these subjects.

379\. Beccaria, L., *et al.*, *GH secretion in Prader-Labhard-Willi
syndrome: somatotrope responsiveness to GHRH is enhanced by arginine but
not by pyridostigmine.* J Pediatr Endocrinol Metab, 1996. 9(6): p.
577-83. Low somatotrope responsiveness to secretagogues has been
reported in patients affected by Prader-Labhard-Willi Syndrome (PLWS).
In normal subjects, GH response to GHRH is known to be greatly
potentiated to the same extent by pyridostigmine (PD) or arginine (ARG)
which probably act via inhibition of hypothalamic somatostatin release.
To clarify somatotrope responsiveness in 7 PLWS patients, we studied GH
response to GHRH alone and to GHRH combined with PD or ARG. Eight normal
short children were studied as controls (NC). GH response to GHRH in
PLWS was lower than in NC (AUC: 615 +/- 205 micrograms/l.h, vs 1271 +/-
333 micrograms/l.h, p \< 0.02). In NC, the GHRH-induced GH rise was
potentiated to the same extent by PD or ARG. In contrast, in PLWS PD
failed to increase the GH response to GHRH (AUC: 615 +/- 205
micrograms/l.h vs 621 +/- 176 micrograms/l.h, n.s.) which was enhanced
by ARG (AUC: 615 +/- 205 micrograms/l.h vs 1633 +/- 425 micrograms/l.h,
p \< 0.02). However, the GH response to GHRH + ARG in PLWS was lower
than in NC. In conclusion, our results demonstrate that in PLWS the low
somatotrope responsiveness to GHRH is not enhanced by cholinergic
potentiation while it is increased by arginine.

380\. Bellone, J., *et al.*, *Comparison of the potentiating effect of
pyridostigmine, arginine and propranolol on the GHRH-induced GH release
in short children.* Panminerva Med, 1993. 35(1): p. 1-4. The effect of
pyridostigmine (60 mg orally), arginine (0.5 g/kg iv) and propranolol
(PROP, 40 mg orally) on GHRH (1 microgram/kg iv)-induced GH release was
studied in seven short children. Pyridostigmine and arginine induced a
similar potentiating effect on GHRH-induced GH rise (Peak, mean +/- SEM:
56.9 +/- 12.8 and 48.6 +/- 8.5 micrograms/L, respectively vs 12.3 +/-
1.6 micrograms/L; p \< 0.05). Combination of GHRH with propranolol
induced an increase of GH that was significant only with regard to peak
(28.9 +/- 8.4 micrograms/L) but not to AUC. However, GH rises observed
after GHRH combined with PD or ARG did not significantly differ from
that recorded after coadministration of GHRH and PROP both for peak and
AUC. Our results confirm that pyridostigmine and arginine have a
striking potentiating effect on the GHRH-induced GH rise in children and
show that the tests with GHRH + PD and GH + H + ARG are ore reliable
than that with GHRH + PROP to explore the secretory capacity of
somatotroph cells.

381\. Borges, M.H., *et al.*, *Different effects of pyridostigmine on
growth hormone (GH) response to GH-releasing hormone in endogenous and
exogenous hypercortisolemic patients.* Braz J Med Biol Res, 1993.
26(11): p. 1191-200. 1. Somatostatin may play a role in the inhibition
of growth hormone (GH) response to GH-releasing hormone (GHRH) in
hypercortisolism. To examine this hypothesis we studied the effect of
pyridostigmine, a cholinergic agonist that decreases hypothalamic
somatostatin, on the GH response to GHRH in 8 controls, in 6 patients
with endogenous hypercortisolism (3 with Cushing\'s disease and 3 with
adrenal adenomas) and in 8 patients with exogenous hypercortisolism
(lupus erythematosus chronically treated with 20-60 mg/day of
prednisone). Each subject received GHRH(1-29)NH2,100 micrograms iv
twice, preceded by pyridostigmine (120 mg) or placebo, orally. 2. The GH
response to GHRH was significantly blunted in all hypercortisolemic
patients compared to controls both after placebo (GH peak, 5.8 +/- 1.6
vs 46.2 +/- 15.9 micrograms/l, mean +/- SEM) and after pyridostigmine
(15.7 +/- 5.6 vs 77.2 +/- 19.8 micrograms/l). 3. The GH response was
absent in endogenous hypercortisolemic patients compared to the
exogenous group, both after placebo (2.2 +/- 0.3 vs 8.5 +/- 2.4
micrograms/l) and after pyridostigmine (4.9 +/- 2.5 vs 23.8 +/- 8.7
micrograms/l). The GH release after GHRH/pyridostigmine for the
exogenous group was similar to the response of controls treated with
GHRH/placebo. 4. These results confirm that the GH response to GHRH is
blunted in hypercortisolism, although more pronounced in the endogenous
group. Pyridostigmine partially reversed this inhibition in the
exogenous group. Therefore, somatostatin may play a role in the
inhibition of GHRH-induced GH release in exogenous hypercortisolemic
states.

382\. Cappa, M., *et al.*, *The growth hormone response to
pyridostigmine plus growth hormone releasing hormone is not influenced
by pubertal maturation.* J Endocrinol Invest, 1991. 14(1): p. 41-5. We
have evaluated the effect of pubertal maturation on the GH response to
growth hormone releasing hormone (GHRH), pyridostigmine (PD) and the
combined administration of PD + GHRH in a group of short normal
children. Fifteen were prepubertal (13 boys and 2 girls, age 5.0 - 12.5
yr), 10 were early pubertal (8 boys and 2 girls, age 11.5 - 16.9 yr in
Tanner stage 2-3 of pubertal maturation), and 6 were late pubertal (6
boys and 2 girls, age 13.6 - 17.1 yr in Tanner stage 4-5 of pubertal
maturation). All subjects were tested on three occasions with GHRH 1-29
(1 microgram/Kg iv), PD (60 mg po) and PD + GHRH (60 mg PD administered
orally 60 min before GHRH). Peak GH levels after GHRH, PD, and PD + GHRH
in the prepubertal children (16.0 +/- 2.8, 8.1 +/- 1.3 and 51.1 +/- 5.5
ng/ml, mean +/- SE, respectively) were not different from those observed
in the early pubertal (18.4 +/- 2.1, 9.1 +/- 1.9 and 41.2 +/- 5.6 ng/ml,
respectively) and in the late pubertal group (14.9 +/- 2.3, 13.1 +/- 2.4
and 42.6 +/- 2.9 ng/ml, respectively). Evaluation of the area under the
curve (AUC) also showed no difference in the GH response to GHRH, PD and
PD + GHRH between the three groups studied. These results confirm that
the combination PD + GHRH is a powerful test to study the GH secretory
capacity of the pituitary, and show that pubertal maturation has no
effect on the GH response to this test.

383\. Cappa, M., *et al.*, *Effect of the enhancement of the cholinergic
tone by pyridostigmine on the exercise-induced growth hormone release in
man.* J Endocrinol Invest, 1993. 16(6): p. 421-4. We have evaluated the
effect of pyridostigmine (PD), a cholinergic agonist, on the growth
hormone (GH) response to physical exercise (EXC) in nine healthy
volunteers. PD administration and EXC caused a similar increase of GH
secretion to mean (+/- SE) peak values of 5.3 +/- 0.9 and 6.5 +/- 1.2
micrograms/l, respectively. Pretreatment with PD caused a significant
augmentation of the EXC-induced GH release evaluated both as maximum
peak (13.5 +/- 2.1 micrograms/l, p \< 0.01 vs EXC) and as area under the
secretory curve (EXC = 292.6 +/- 41.9 micrograms.min.l; PD + EXC = 587.3
+/- 68.9 micrograms.min.l, p \< 0.005). The action of PD on GH secretion
was additive to that of EXC since the sum of the GH responses to PD and
EXC was not significantly different from the response obtained during
PD + EXC. Whether PD and EXC act through a common final pathway, i.e.
inhibition of endogenous somatostatin release, or the EXC-induced GH
secretion involves stimulation of endogenous GHRH remains matter of
investigation.

384\. Cappa, M., *et al.*, *Growth hormone (GH) response to combined
pyridostigmine and GH-releasing hormone administration in patients with
Prader-Labhard-Willi syndrome.* Horm Res, 1993. 39(1-2): p. 51-5. We
evaluated the GH response to combined administration of pyridostigmine
(PD), a cholinergic agonist, and GH-releasing hormone (GHRH) (60 mg PD
given orally 60 min before the GHRH bolus) as well as baseline IGF-I
concentrations in 10 patients (5 males and 5 females, age 6.0-24 years)
with Prader-Labhard-Willi (PLW) syndrome, 8 prepubertal obese children
(4 males and 4 females, age 5.6-12.0 years) and 9 prepubertal short
normal children (7 males and 2 females, age 8.0-12.8 years). Mean GH
responses to PD+GHRH were significantly lower (p \< 0.0001) in the PLW
patients (13.8 +/- 3.3 micrograms/l) than in the short normal children
(52.2 +/- 9.0 micrograms/l) and similar to those of the obese children
(14.3 +/- 3.2 micrograms/l). Mean serum IGF-I levels were significantly
lower (p \< 0.05) in the PLW patients (117.5 +/- 26.4 micrograms/l) than
in the obese (329.3 +/- 88.0 micrograms/l) and the short normal children
(214.3 +/- 38.3 micrograms/l). Two of the PLW patients had absent GH
responses to PD+GHRH associated with subnormal IGF-I concentrations,
indicating pituitary GH deficiency. When these 2 cases were excluded
from the statistical calculation, mean peak GH responses to PD+GHRH
remained significantly lower (p \< 0.0001) in the PLW patients (17.1 +/-
3.0 micrograms/l), while their mean serum IGF-I concentrations (143.4
+/- 71.5 micrograms/l) were not significantly different from those of
the other two groups. These results indicate that patients with the PLW
syndrome have a reduced or absent GH secretory reserve associated in
some cases with low levels of IGF-I.(ABSTRACT TRUNCATED AT 250 WORDS).

385\. Castro, R.C., *et al.*, *Pyridostigmine enhances, but does not
normalise, the GH response to GH-releasing hormone in obese subjects.*
Acta Endocrinol (Copenh), 1990. 122(3): p. 385-90. Obese patients are
characterised by several neuroendocrine abnormalities, including
characteristically a decrease in growth hormone responsiveness to
GH-releasing hormone. In normal subjects, the GH response to GHRH is
enhanced by the acetylcholinesterase inhibitor, pyridostigmine. We have
studied the effect of this drug on GH secretion in gross obesity. Twelve
obese patients were studied (mean weight 156% of ideal) and compared
with a group of 8 normal volunteers. Each subject was initially studied
on two occasions, in random order, with GHRH (1-29) NH2 100 micrograms
iv alone and following pretreatment with pyridostigmine 120 mg orally
one hour prior to GHRH. In obese patients, the GH response to GHRH was
significantly blunted when compared to controls (GH peak: 20 +/- 4 vs 44
+/- 16 micrograms/l; mean +/- SEM). After pyridostigmine, the response
to GHRH was enhanced in the obese subjects, but remained significantly
reduced compared to non-obese subjects treated with GHRH and
pyridostigmine (GH peak: 30 +/- 5 vs 77 +/- 20 micrograms/l,
respectively). In 6 subjects, higher doses of GHRH or pyridostigmine did
not further increase GH responsiveness in obese patients. Our results
suggest that obese patients have a disturbed cholinergic control of GH
release, probably resulting from increased somatostatinergic tone. This
disturbed regulation may be responsible, at least in part, for the
blunted GH responses to provocative stimuli.

386\. Coiro, V., *et al.*, *Effect of potentiation of cholinergic tone
by pyridostigmine on the GH response to GHRH in elderly men.*
Gerontology, 1992. 38(4): p. 217-22. The plasma GH response to GHRH (100
micrograms i.v.) was evaluated either alone or after pretreatment with
pyridostigmine (120 mg orally 1 h prior to GHRH) in 9 younger men (age
range: 22-39 years) and in 9 healthy elderly men (age range: 63-77
years). On a different occasion, subjects were tested with
pyridostigmine alone. Basal concentrations of glucose, cortisol,
androgens, estrogens, thyroid hormones and GH were similar in all
subjects, whereas insulin-like growth factor was lower in elderly men.
The GH response to GHRH was significantly lower in the older (mean peak
was 6 times higher than baseline) than in the younger group (mean peak
was 11.3 times higher than baseline). The pretreatment with
pyridostigmine induced a striking increase in the GH response to GHRH in
the younger subjects (mean peak was 26 times higher than baseline),
whereas it produced only a slight increase in the GHRH-induced GH
response in elderly men (mean peak was 8.7 times higher than baseline).
When pyridostigmine was given alone, plasma GH levels rose significantly
in both groups; however, the pyridostigmine-stimulated GH response was
significantly higher in younger (mean peak was 6 times higher than
baseline) than in older subjects (mean peak was 2.5 times higher than
baseline). These data indicate that the cholinergic stimulatory
regulation of GH release is reduced in elderly subjects. Since
acetylcholine inhibits hypothalamic somatostatin release, the reduced
cholinergic tone in elderly subjects may result in an increased
somatostatinergic tone.

387\. Coiro, V., *et al.*, *Different effects of naloxone on the growth
hormone response to melatonin and pyridostigmine in normal men.*
Metabolism, 1998. 47(7): p. 814-6. The effect of melatonin (MEL) (12 mg
orally), pyridostigmine (60 mg orally), the combination of MEL and
pyridostigmine, or placebo on growth hormone (GH) secretion was tested
in seven normal men. In addition, MEL tests and pyridostigmine tests
were repeated after pretreatment with naloxone (1.2-mg bolus followed by
intravenous \[i.v.\] infusion of 1.6 mg/h for 3 hours). Serum GH levels
increased fivefold after MEL and sixfold after pyridostigmine
administration. The concomitant administration of MEL did not change the
GH response to pyridostigmine. In the presence of naloxone, the GH
response to MEL was completely abolished, whereas naloxone did not
modify the pyridostigmine-induced GH increase. These data suggest that
MEL and pyridostigmine stimulate GH secretion through a common
mechanism, which is probably represented by the inhibition of
somatostatin activity. However, in contrast to pyridostigmine, the
action of MEL appears to be exerted through a naloxone-sensitive opioid
mediation.

388\. Cooney, J.M., *et al.*, *Specificity of the pyridostigmine/growth
hormone challenge in the diagnosis of depression.* Biol Psychiatry,
1997. 42(9): p. 827-33. Acetylcholine is a neurotransmitter that has
been implicated in the pathophysiology of major depression. This is
supported by the enhanced growth hormone (GH) release in response to
pyridostigmine (PYD) challenge in depressed subjects relative to healthy
comparison subjects. The aim of this study is to examine the specificity
of the PYD/GH challenge in the diagnosis of depression. Pyridostigmine
120 mg orally, was administered to a total of 116 physically healthy
subjects. Growth hormone responses were studied in 38 patients with
(DSM-III-R) major depression, 13 subjects with panic disorder, 9
subjects with schizophrenia, 10 recently detoxified alcoholics, and a
comparison group of 46 healthy volunteers. Mean delta GH (the difference
between basal and maximal GH following PYD) was significantly greater
than comparison subjects in patients with major depression. Responses
observed in patients with schizophrenia and alcohol dependence syndrome
did not differ from the comparison group. Those patients with panic
disorder and a high Hamilton depression score had an enhanced delta GH.
The sensitivity of the PYD/GH test was 63% for major depression. These
results indicate that the PYD/GH test may help distinguish depression
from schizophrenia, alcohol-dependence syndrome, or panic disorder with
a low Hamilton depression score.

389\. Cooney, J.M., J.V. Lucey, and T.G. Dinan, *Enhanced growth hormone
responses to pyridostigmine challenge in patients with panic disorder.*
Br J Psychiatry, 1997. 170: p. 159-61. BACKGROUND: Panic disorder is
associated with neuroendocrinological abnormalities, some of which
overlap with those seen in major depression. To date, there has been
little assessment of the role of cholinergic mechanisms in this
disorder. METHOD: Sixteen patients with DSM-III-R panic disorder and an
age and gender-matched comparison group were administered 120 mg of the
acetylcholinesterase inhibitor pyridostigmine. Growth hormone (GH)
responses over a three-hour period were monitored. RESULTS: Mean delta
GH, the difference between basal and the maximum pyridostigmine levels,
was significantly greater in patients with panic disorder than in the
comparison group. CONCLUSIONS: This may reflect increased cholinergic
responsivity in panic disorder.

390\. Cordido, F., F.F. Casanueva, and C. Dieguez, *Cholinergic receptor
activation by pyridostigmine restores growth hormone (GH) responsiveness
to GH-releasing hormone administration in obese subjects: evidence for
hypothalamic somatostatinergic participation in the blunted GH release
of obesity.* J Clin Endocrinol Metab, 1989. 68(2): p. 290-3. GH
secretion in response to provocative stimuli is decreased in obese
individuals. However, the precise mechanism causing this decrease is
unknown. In an attempt to determine if reduced cholinergic stimulation
accounts for the decreased GH secretion, we studied the effect of
enhanced cholinergic tone induced by pyridostigmine on GHRH-stimulated
GH secretion in a group of seven obese and seven normal subjects. When
GHRH (100 micrograms, iv) was administered after placebo in the obese
group, mean plasma GH rose from 0.5 +/- (0.1 (+/- SE) to 3.6 +/- 1.5
micrograms/L at 30 min. When the same obese subjects were given GHRH 60
min after pyridostigmine administration (120 mg, orally), the mean
plasma GH level rose from 1.8 +/- 0.6 to 21.0 +/- 7.5 micrograms/L at 30
min. The responses to placebo and pyridostigmine were significantly
different at 15, 30, 45, 60, and 90 min. In the normal subjects, a
similar dose of GHRH induced a GH peak of 24.3 +/- 7.1 micrograms/L, and
the GHRH-stimulated peak was significantly higher (56.2 +/- 16.8
micrograms/L) after pyridostigmine administration. To study the effect
of pyridostigmine alone six other obese and six other normal subjects
were tested with pyridostigmine or placebo on different days. In the
normal subjects the mean peak plasma GH level after pyridostigmine was
12.5 +/- 3.1 micrograms/L, and in the obese subjects it was 4.6 +/- 1.3
micrograms/L. Thus, pyridostigmine potentiated the action of GHRH,
rather than merely being additive. We conclude that pyridostigmine
stimulates GH secretion in obese as well as normal subjects, although
the response was less in the former group. Pyridostigmine potentiates
the response to GHRH in both groups, but again, the response was less in
the obese subjects. These results suggest that the impaired somatotroph
responsiveness in obese subjects may be due to chronically decreased
hypothalamic cholinergic tone, resulting in enhanced somatostatinergic
tone.

391\. Cordido, F., C. Dieguez, and F.F. Casanueva, *Effect of central
cholinergic neurotransmission enhancement by pyridostigmine on the
growth hormone secretion elicited by clonidine, arginine, or
hypoglycemia in normal and obese subjects.* J Clin Endocrinol Metab,
1990. 70(5): p. 1361-70. Obesity is associated with an impairment of the
GH secretion elicited by all stimuli known to date, but the basic
mechanism of this alteration is unknown. To determine whether obesity is
associated with a chronic state of tonic somatostatin secretion, several
tests with GH stimuli with or without pyridostigmine were undertaken in
both obese subjects and matched controls. Pyridostigmine reduces
somatostatin release from the hypothalamus by increasing central
cholinergic neurotransmission. The administration of clonidine (300
micrograms, orally) to obese subjects did not modify basal GH values
(1.9 +/- 0.7 micrograms/L at 90 min), while in control subjects the
clonidine-induced GH peak was 13.1 +/- 1.6 micrograms/L. Pretreatment
with pyridostigmine (120 mg, orally) notably increased
clonidine-stimulated GH secretion in both the obese (6.9 +/- 1.8
micrograms/L) and control (17.6 +/- 2.7 micrograms/L) subjects. Since
clonidine acts by releasing endogenous GHRH, similar studies were
undertaken employing arginine, which presumably enhances GH release by
reducing somatostatin discharge. Arginine administration in obese
subjects induced an increase in GH levels of 5 +/- 2.3 micrograms/L,
which was significantly smaller than that in the matched control
subjects (13.3 +/- 2.4 micrograms/L). Pretreatment with pyridostigmine
increased the arginine action toward a GH peak of 12.2 +/- 2.2
micrograms/L in the obese and 21.6 +/- 2.5 micrograms/L in control
subjects. As a third hypothalamic stimulus of GH secretion, trials of
insulin-induced hypoglycemia were carried out. Hypoglycemia induced an
increase in GH levels in obese subjects of 12.2 +/- 1.8 micrograms/L,
which was higher than that produced by any other stimulus, but lower
than that in control subjects (28.4 +/- 5.5 micrograms/L). In contrast
with the previous two GH stimuli, pretreatment with pyridostigmine did
not modify the hypoglycemia-induced GH release in either obese or normal
subjects. Our results lend support to the view that clonidine acts
through GH-releasing hormone release and arginine by reducing
somatostatin discharge from the hypothalamus. In addition, they seem to
indicate that hypoglycemia acts by a combination of both mechanisms,
mainly through a reduction in somatostatin release. These findings
support the idea that obesity is associated with a state of chronic
somatostatin hypersecretion as the basis for the derangements in GH
secretion.

392\. Cordido, F., *et al.*, *Effect of combined administration of
growth hormone (GH)-releasing hormone, GH-releasing peptide-6, and
pyridostigmine in normal and obese subjects.* Metabolism, 1995. 44(6):
p. 745-8. Growth hormone (GH) secretion in response to all provocative
stimuli is decreased in patients with obesity. Recently, we found that
the combined administration of GH-releasing hormone (GHRH) and the
hexapeptide GH-releasing peptide-6 (GHRP-6) induced a large increase in
plasma GH levels. To gain further insight into the disrupted mechanism
of GH regulation in obesity, we investigated whether the inhibition of
somatostatinergic tone with pyridostigmine could further increase the GH
response to combined administration of GHRH and GHRP-6. In normal
subjects, administration of GHRH plus GHRP-6 induced a marked increase
in plasma GH with a peak at 30 minutes (mean +/- SEM, 76.7 +/- 9.7
micrograms/L), which was similar to that obtained after pretreatment
with pyridostigmine (74.7 +/- 9.4 micrograms/L). In obese patients,
combined administration of GHRH plus GHRP-6 induced a clear increase in
GH secretion with a peak at 15 minutes of 42.2 +/- 10.0 micrograms/L,
which was also unaffected after pretreatment with pyridostigmine (38.4
+/- 5.8 micrograms/L). The GH response was lower in obese patients than
in controls as assessed by the area under the curve after administration
of both GHRH plus GHRP-6 (1,846 +/- 396 v 4,773 +/- 653, P \< .01) and
pyridostigmine plus GHRH plus GHRP-6 (1,989 +/- 372 v 5,098 +/- 679, P
\< .005). In conclusion, these data suggest that GHRP-6 can behave as a
functional somatostatin antagonist, and that somatotrope responsiveness
to the combined administration of GHRH plus GHRP-6 is largely
independent of somatostatinergic tone.(ABSTRACT TRUNCATED AT 250 WORDS).

393\. Corsello, S.M., *et al.*, *Effects of sex and age on
pyridostigmine potentiation of growth hormone-releasing hormone-induced
growth hormone release.* Neuroendocrinology, 1992. 56(2): p. 208-13.
Previous studies have shown that pyridostigmine (PD) is capable of
increasing the growth hormone (GH) response to GH-releasing hormone
(GHRH) in young healthy subjects. In order to investigate the influence
of age and sex on the PD potentiation of GHRH-induced GH release, we
have studied the GH response to GHRH (50 micrograms i.v.) 1 h after oral
administration of placebo or PD (60 mg) in 8 young healthy men (aged
19-28 years) and 8 age-matched young women (aged 18-25 years) during the
follicular phase of the menstrual cycle, as well as in 8 postmenopausal
women (aged 57-62 years) and 8 age-matched elderly men (aged 56-64
years). In the same subjects the effect of PD alone (60 mg p.o.) was
also studied. Furthermore, in 6 postmenopausal women and 6 elderly men,
the effect of a 30-mg PD oral dose on GH secretion and GH response to
GHRH was evaluated with a similar protocol. The GH responses (mean +/-
SE) to GHRH + placebo were similar in young men (peak 20.1 +/- 2 ng/ml,
AUC 1,250 +/- 113 ng/ml/min) and women (peak 29.3 +/- 2.3 ng/ml, AUC
1,769 +/- 305 ng/ml/min). PD 60 mg was capable of significantly
increasing the GH response to GHRH in young men (peak 43.5 +/- 5.1
ng/ml, AUC 3,734 +/- 472 ng/ml/min, p less than 0.005) but not in women
(peak 39 +/- 2.3 ng/ml, AUC 2,479 +/- 205 ng/ml/min).(ABSTRACT TRUNCATED
AT 250 WORDS).

394\. Corsello, S.M., *et al.*, *Activation of cholinergic tone by
pyridostigmine reverses the inhibitory effect of corticotropin-releasing
hormone on the growth hormone-releasing hormone-induced growth hormone
secretion.* Acta Endocrinol (Copenh), 1992. 126(2): p. 113-6. Previous
studies have shown that corticotropin-releasing hormone (CRH) is capable
of inhibiting growth hormone (GH) secretion in response to GH-releasing
hormone (GHRH). In an attempt to clarify the mechanism of the CRH
action, we have studied the effect of enhanced cholinergic tone induced
by pyridostigmine on the CRH inhibition of the GH response to GHRH in a
group of six normal men and six normal women. All subjects presented a
normal GH response to 50 micrograms i.v. GHRH administration (mean peak
+/- SEM plasma GH levels 20 +/- 2.9 micrograms/l in men and 28.9 +/- 2.9
micrograms/l in women) with a further significant increase after
pyridostigmine pretreatment (60 mg orally given 60 min before GHRH) in
men (GH peaks 43.1 +/- 6.9 micrograms/l, p less than 0.005) but not in
women (GH peaks 39.2 +/- 3.0 micrograms/l). In the same subjects,
peripherally injected CRH (100 micrograms) significantly inhibited the
GH response to GHRH (GH peaks 8.1 +/- 0.6 micrograms/l in men, p less
than 0.005 and 9.9 +/- 0.7 micrograms/l in women, p less than 0.005).
Pyridostigmine (60 mg) given orally at the same time of CRH
administration (60 min before GHRH) reversed the CRH inhibition of
GHRH-induced GH secretion (GH peaks 35.3 +/- 8.2 micrograms/l in men and
35 +/- 3.3 micrograms/l in women) with a response not significantly
different to that seen in the pyridostigmine plus GHRH test. Our data
confirm that pyridostigmine is capable of potentiating the GHRH-induced
GH release in normal male but not female subjects.(ABSTRACT TRUNCATED AT
250 WORDS).

395\. Davis, B.M., *et al.*, *Clinical studies of the cholinergic
deficit in Alzheimer\'s disease. I. Neurochemical and neuroendocrine
studies.* J Am Geriatr Soc, 1985. 33(11): p. 741-8. Autopsy studies
indicating that cholinergic neurons are selectively lost in patients
with Alzheimer\'s disease (AD) and senile dementia of the Alzheimer type
(SDAT) suggest that peripheral markers for central cholinergic activity
would be useful in diagnosis. The present studies found that
cerebrospinal fluid (CSF) concentrations of acetylcholine (ACh)
correlated with the degree of cognitive impairment (r = .70) in a sample
of carefully diagnosed patients with AD/SDAT, but metabolites of other
neurotransmitters were not related to cognitive state; this suggests
that CSF ACh may be a valid measure of cholinergic degeneration.
Cortisol and growth hormone were measured in plasma samples drawn from
patients and controls every 30 minutes from 2100 to 1100 hours the next
day. Mean plasma cortisol concentrations were higher in patients with
AD/SDAT than in controls and correlated inversely with CSF
methoxy-hydroxyphenylglycol (MHPG) (r = .61) and positively with degree
of cognitive impairment (r = +.53); as anticholinergic drugs suppress
cortisol this finding indicates that cortisol dysregulation may be a
marker for abnormalities in other neurotransmitter systems, particularly
the noradrenergic system. Growth hormone secretion was not different in
patients and controls but was positively correlated with CSF MHPG (r =
+.63).

396\. De Marinis, L., *et al.*, *Influence of pyridostigmine on growth
hormone (GH) response to GH-releasing hormone pre- and postprandially in
normal and obese subjects.* J Clin Endocrinol Metab, 1992. 74(6): p.
1253-7. The effect of pyridostigmine (PYR), an inhibitor of
acetylcholinesterase, on the GH response to GH-releasing hormone (GHRH)
before and after a meal was studied in 14 normal subjects (8 females and
6 males) and 21 obese subjects (13 females and 8 males). In normal
subjects tested in a fasting state, PYR was capable of stimulating GH
secretion and increasing the GH response to GHRH. These effects were not
apparent after food, suggesting a reduction in cholinergic hypothalamic
activity. In obese subjects tested in a fasting state, PYR was
ineffective when administered alone. On the contrary, it was able to
increase the GH response to GHRH. After food, the augmenting effect of
PYR on the GH response to GHRH was not observed, whereas a delayed
inhibition of the GH response was found after PYR plus GHRH treatment.
Our findings support the hypothesis that cholinergic hypothalamic
activity plays a pivotal role in impaired GH regulation and the altered
sensitivity of GH secretion to metabolic fuels in obese subjects.

397\. del Balzo, P., *et al.*, *Pyridostigmine does not reverse
dexamethasone-induced growth hormone inhibition.* Clin Endocrinol (Oxf),
1990. 33(5): p. 605-12. Glucocorticoids inhibit the growth hormone (GH)
response to a variety of stimuli, including GH-releasing hormone (GHRH)
in vivo, but they increase GHRH-stimulated GH secretion when added, in
vitro, to animal and human pituitary cells. This discrepancy has led to
the hypothesis that glucocorticoids act in vivo by increasing
somatostatin secretion from the hypothalamus. To examine this
hypothesis, we used a cholinergic drug, pyridostigmine (PD), which
reduces hypothalamic somatostatin secretion. Eight normal volunteers
were studied. They underwent four tests: (1) GHRH test; (2) Dex + GHRH
(GHRH test after treatment the night before, with dexamethasone (Dex));
(3) PD + GHRH; (4) Dex + PD + GHRH. Dex significantly inhibited the GH
response to GHRH expressed as area under the GH/time curve (AUC,
microgram/1/min) (mean +/- SEM = 895.2 +/- 196.6 vs 1970.9 +/- 600.1, P
less than 0.05). PD significantly increased the AUC of GH secretion in
PD + GHRH compared with GHRH alone (3541.2 +/- 571.3 vs 1970.9 +/-
600.1, P less than 0.01) but by no means restored completely the normal
GH response to GHRH, when given to Dex-pretreated subjects. Furthermore,
the mean AUC of Dex + PD + GHRH was significantly lower than that of
PD + GHRH (1621.7 +/- 500.6 vs 3541.2 +/- 571.3, P less than 0.01),
demonstrating that Dex continues to exert its inhibitory effect on GH
secretion in the presence of PD. These results suggest that
glucocorticoid-induced GH inhibition does not act solely through an
increase in hypothalamic somatostatin secretion.

398\. Del Rio, G., *et al.*, *Effect of testosterone replacement therapy
on the somatotrope responsiveness to GHRH alone or combined with
pyridostigmine and on sympathoadrenal activity in patients with
hypogonadism.* J Endocrinol Invest, 1995. 18(9): p. 690-5. There is
evidence suggesting that androgens influence GH secretion in man. Our
aim was to verify whether the GH releasable pool is preserved and
influenced by testosterone replacement in male hypogonadism. To this
goal, in eight male hypogonadal patients (HP, age 32.2 +/- 5.0 yr; Body
Mass Index 23.9 +/- 1.1 kg/m2) before and after 3 months testosterone
therapy, we studied the GH response to GHRH (1 microgram/kg iv) alone
and combined with pyridostigmine (PD, 120 mg po), a cholinesterase
inhibitor which likely inhibits hypothalamic somatostatin release
allowing exploration of the maximal somatotrope secretory pool. Sixteen
normal subjects (NS, age 30.1 +/- 3.5 yr; Body Mass Index 22.5 +/- 1.8
kg/m2) were studied as controls. The GH response to GHRH in HP was
similar to that in NS (AUC, mean +/- SE: 1238 +/- 362 vs 1018 +/- 182
micrograms/L/h). PD potentiated to the same extent the GH response to
GHRH in both groups (2092 +/- 807 and 2840 +/- 356 micrograms/L/h).
After three month testosterone therapy, in HP the GH responses to GHRH
alone (1352 +/- 612 micrograms/L/h) and combined with PD (1948 +/- 616
microgram/L/h) were unchanged. Also IGF-I levels in HP were similar to
those in NS (222 +/- 42 vs 210.6 +/- 55.8 micrograms/L) and were
unchanged during testosterone replacement (280 +/- 31 micrograms/L). As
androgens have been reported to modulate sympathoadrenal activity in the
rat, both before and during testosterone replacement, we also measured
plasma catecholamine levels. Basal NE (p \< 0.05) but not E levels were
lower in HP than in NS; testosterone restored basal NE levels to normal
without affecting basal E. delta absolute increase of NE and E (p \<
0.05 and 0.01 vs baseline, respectively) after PD in HP were similar to
those in NS and were unchanged during testosterone replacement. In
conclusion, these results demonstrate that the GH releasable pool is
preserved in male hypogonadism. As in this condition a reduction of
spontaneous GH secretion has been reported, it could be due to
neurosecretory dysfunction but not to pituitary impairment. Subtle
alterations of sympathoadrenal activity seem to be present in male
hypogonadism and reversed by testosterone replacement.

399\. Delitala, G., *et al.*, *Interaction of glucose and pyridostigmine
on the secretion of growth hormone (GH) induced by GH-releasing hormone
(GHRH).* J Endocrinol Invest, 1990. 13(8): p. 653-6. In order to
investigate the mechanisms by which hyperglycaemia induces an inhibition
of GHRH-induced GH release, we gave the following treatments to seven
normal men: a) GHRH 100 micrograms iv; b) pyridostigmine (PD) 120 mg po
60 min before GHRH; c) glucose 250 mg/kg iv as a bolus (10 min before
GHRH) plus 10 mg/kg/min until the end of the test; d) glucose
pyridostigmine and GHRH as above. Glucose significantly reduced
GHRH-stimulated GH levels, whereas PD significantly enhanced them. When
PD and glucose were given together, the effect on GHRH-stimulated GH
secretion was not different from the algebraic sum of the single effects
of the two substances. Thus glucose seems to be able to exert its
inhibition, at least partially, also when pyridostigmine is
coadministered.

400\. Dinan, T.G., V. O\'Keane, and J. Thakore, *Pyridostigmine induced
growth hormone release in mania: focus on the cholinergic/somatostatin
system.* Clin Endocrinol (Oxf), 1994. 40(1): p. 93-6. OBJECTIVE: The
release of growth hormone (GH) from the anterior pituitary is partly
under cholinergic control. Pyridostigmine, the acetylcholinesterase
inhibitor, releases GH by this mechanism. Pyridostigmine/GH responses
have been reported as enhanced in depression. The aim of the current
study was to examine such responses during a manic episode. DESIGN: A
between subjects design was employed. SUBJECTS: Seven male manic
patients and seven male healthy controls were studied. They were matched
in terms of age and body mass index. MEASUREMENTS: GH response to
pyridostigmine (120 mg) challenge was measured as the net increase above
baseline. Cortisol levels were also measured. RESULTS: Release of GH in
the manic patients was significantly enhanced and their baseline
cortisol levels were elevated. CONCLUSIONS: These results demonstrate
enhanced pyridostigmine/GH responsiveness in mania which may be due to
enhanced somatostatin tone or increased cholinergic receptor
responsivity.

401\. Dinan, T.G., *et al.*, *Altered hypothalamic cholinergic responses
in patients with nonulcer dyspepsia: a study of
pyridostigmine-stimulated growth hormone release.* Am J Gastroenterol,
2002. 97(8): p. 1937-40. OBJECTIVE: Acetylcholine plays a central and
peripheral role in regulating gastric motility. In the hypothalamus, it
is a key neuroendocrine modulator; acting through somatostatin, it
brings about the release of growth hormone (GH). We measured
hypothalamic cholinergic receptor sensitivity in patients with nonulcer
dyspepsia (NUD) by examining GH release in response to cholinergic
challenge. METHODS: Forty patients with NUD and 40 healthy comparison
subjects were administered pyridostigmine (the acetylcholinesterase
inhibitor, 120 mg), and GH release over a 3-h period was monitored.
RESULTS: Calculating response as the maximum GH relative to baseline
(delta GH), the mean +/- SEM response in the patients was 11.9 +/- 1.9
U/L and in the healthy subjects 6.7 +/- 0.7 mU/L (t = 2.1, df = 78, p =
0.03). Helicobacter pylori status had no appreciable impact on GH
response with H. pylori-positive patients having a mean response of 10.5
+/- 2.1 mU/L and negative patients a mean response of 13.2 +/- 3.4 mU/L.
Overall, patients with NUD release more GH in response to pyridostigmine
challenge than healthy subjects. CONCLUSIONS: Patients with NUD may have
a pathophysiological disturbance involving central cholinergic systems.

402\. Farello, G., *et al.*, *\[Effect of pre-treatment with
pyridostigmine on the stimulation of growth hormone by clonidine and
GRF\].* Minerva Pediatr, 1991. 43(10): p. 617-20. The large availability
of biosynthetic GH suggested the need to define the more accurate way to
make diagnosis of GH deficit. Only one stimulation test by clonidine or
insulin is not enough to define a GH deficit, and this because often
it\'s possible to get \"false negative\" tests. The GH is regulated by
the influence of GRF and somatostatin that respectively are under the
adrenergic and cholinergic control, for this reason we studied how and
in which measure a cholinergic agonist (pyridostigmine) acts on GH
release during the clonidine and GRF stimulation tests. We studied the
area under the curve (AUC), the peak and the mean of the value of GH
after clonidine or clonidine and pyridostigmine, and after GRF or GRF
and pyridostigmine: we got the following results: 191 +/- 71.33 (AUC),
5.42 +/- 1.68 (peak), 2.44 +/- 0.54 (mean) after clonidine stimulation
test; 1048 +/- 442.37 (AUC), 19.5 +/- 10.15 (peak) and 7.96 +/- 3.2
(mean) after clonidine and pyridostigmine (p less than 0.01); 1499 +/-
887 (AUC), 21.1 +/- 11.8 (peak) and 11.11 +/- 6.6 (mean) after GRF test
and 2370 +/- 332 (AUC), 31.4 +/- 3.49 (peak) and 18.22 +/- 3.27 (mean)
after GRF and pyridostigmine. The pyridostigmine effect on the
simulation by clonidine and GRF is able to potentiate the stimulation of
GH and allowed a more accurate diagnosis of GH deficit.

403\. Friend, K., *et al.*, *Pyridostigmine treatment selectively
amplifies the mass of GH secreted per burst without altering GH burst
frequency, half-life, basal GH secretion or the orderliness of GH
release.* Eur J Endocrinol, 1997. 137(4): p. 377-86. Growth hormone (GH)
release from the anterior pituitary gland is predominantly regulated by
the two antagonistic hypothalamic peptides, growth hormone-releasing
hormone (GHRH) and somatostatin. Appraising endogenous GHRH action is
thus made difficult by the confounding effects of (variable)
hypothalamic somatostatin inhibitory tone. Accordingly, to evaluate
endogenous GHRH actions, we used a clinical model of presumptively acute
endogenous somatostatin withdrawal with concomitant GHRH release. To
this end, we administered in randomized order placebo or the indirect
cholinergic agonist, pyridostigmine, for 48 h to 13 healthy men of
varying ages (29-77 years) and body mass indices (21-47 kg/m2). We
sampled blood at 10-min intervals for 48 h during both placebo and
pyridostigmine (60 mg orally every 6 h) administration, and used an
ultrasensitive GH chemiluminescence assay (sensitivity 0.0002-0.005
microgram/l) to capture GH pulse profiles. Multiparameter deconvolution
analysis was applied to quantitate the number, amplitude, mass, and
duration of significant underlying GH secretory bursts, and
simultaneously estimate the GH half-life and concurrent basal GH
secretion. Approximate entropy was utilized as a novel regularity
statistic to quantify the relative orderliness of the hormone release
process. All measures of GH secretion/half-life and orderliness were
statistically invariant across the two consecutive 24-h placebo
sessions. In contrast, pyridostigmine treatment significantly increased
the mean serum GH concentration from 0.23 +/- 0.054 microgram/l during
placebo to 0.45 +/- 0.072 microgram/l during the first day of treatment
(P \< 0.01). There was also a significant rise in the calculated 24-h
pulsatile GH production rate from 8.9 +/- 1.7 micrograms/l/day on
placebo to 27 +/- 5.6 micrograms/l/day during active drug treatment (P
\< 0.01). Pyridostigmine significantly and selectively amplified GH
secretory burst mass to 1.5 +/- 0.35 micrograms/l compared with 0.74 +/-
0.19 microgram/l on placebo (P \< 0.01). This was attributable to
stimulation of GH secretory burst amplitude (maximal rate of GH
secretion attained within the release episode) with no prolongation of
estimated burst duration. Basal GH secretion and approximate entropy
were not altered by pyridostigmine. However, age was strongly related to
more disorderly GH release during both days of pyridostigmine treatment
(r = +0.79, P = 0.0013). During the second 24-h of continued
pyridostigmine treatment, most GH secretory parameters decreased by
15-50%, but in several instances remained significantly elevated above
placebo. Body mass index, but not age, was a significantly negative
correlate of the pyridostigmine-stimulated increase in GH secretion (r =
-0.65, P = 0.017). In summary, assuming that somatostatin is withdrawn
and (rebound) GHRH release is stimulated via pyridostigmine
administration, we infer that relatively unopposed GHRH action
principally controls GH secretory burst mass and amplitude, rather than
apparent GH secretory pulse duration, the basal GH secretion rate, or
the serial regularity/orderliness of the GH release process in the
human. Moreover, we infer that increasing age is accompanied by greater
disorderliness of somatostatin-withdrawn GHRH, and hence rebound GH,
release. The strongly negative correlation between
pyridostigmine-stimulated GH secretion and body mass index (but not age)
further indicates that increased relative adiposity may result in
decreased effective (somatostatin-withdrawn) endogenous GHRH stimulus
strength.

404\. Ghigo, E., *et al.*, *Growth hormone responses to pyridostigmine
in normal adults and in normal and short children.* Clin Endocrinol
(Oxf), 1987. 27(6): p. 669-73. There is evidence indicating that the
cholinergic system positively modulates GH release probably by
inhibiting somatostatinergic tone. In the present study, the effects of
cholinergic enhancement by pyridostigmine, (PD), a cholinesterases
inhibitor, on GH release in normal adults (n = 14) (NA) and in both
normal (n = 5) (NC) and short children (n = 19) (SC) with familial short
stature (n = 7) or constitutional growth delay (n = 12) were studied. In
SC the insulin hypoglycaemia (IH)-induced GH increase was also studied.
In both NC and SC 60 mg orally PD induced a significant GH increase with
mean peak at 90 min (mean +/- SEM 11.0 +/- 2.2 ng/ml in NC and 11.2 +/-
2.3 ng/ml in SC). The GH areas under response curve (AUC) were 379.3 +/-
76.6 and 327.8 +/- 43.2 ng/ml/h in NC and SC respectively. In NA 120 mg
orally PD induced a significant GH increase with mean peak at 120 min
(5.1 +/- 1.1 ng/ml) which was significantly lower (P less than 0.05)
than that observed in both NC and SC. This statistical difference was
strengthened by evaluating AUC (NA:205.6 +/- 33.7 ng/ml/h, P less than
0.05 vs NC and SC). The correlation of drug dosage with body area ruled
out that this difference could be related to the different PD dose in
adults and children. In SC, IH induced a GH increase significantly lower
than that observed after PD (GH peak 7.8 +/- 0.6 vs 16.4 +/- 1.9 ng/ml P
less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS).

405\. Ghigo, E., *et al.*, *Enhancement of cholinergic tone by
pyridostigmine promotes both basal and growth hormone (GH)-releasing
hormone-induced GH secretion in children of short stature.* J Clin
Endocrinol Metab, 1987. 65(3): p. 452-6. Increased cholinergic tone
induced by pyridostigmine (PD) increases basal plasma GH levels and
potentiates the GH response to GHRH in normal adults. In this study the
effects of PD (60 mg, orally) on both basal and GHRH (1
microgram/kg)-induced GH secretion in seven children with familial short
stature (FSS), six with GH deficiency (GHD) and 10 with constitutional
growth delay (CGD) were studied and compared with results obtained by
stimulation with insulin-induced hypoglycemia (IH) and GHRH alone. The
mean peak plasma GH levels were variable, but individual values were
frequently low in all groups after both IH \[FSS, 9.7 +/- 1.3 (+/- SEM)
ng/mL; GHD, 1.6 +/- 0.4 ng/mL; CGD, 7.0 +/- 0.8 ng/mL\] and GHRH (FSS,
23.8 +/- 6.6 ng/mL; GHD, 11.1 +/- 5.8 ng/mL; CGD, 15.1 +/- 4.5 ng/mL)
administration. PD induced GH responses (FSS, 14.5 +/- 1.6 ng/mL; GHD,
3.8 +/- 0.8 ng/mL; CGD, 18.3 +/- 3.2 ng/mL) that in many children in the
FSS and CGD groups were higher than those after IH and GHRH treatment.
PD clearly increased the GH response to GHRH in all children \[FSS, 69.5
+/- 9.4 ng/mL (P less than 0.01 vs. other stimuli); GHD, 18.0 +/- 7.5
ng/mL; CGD, 50.0 +/- 8.5 ng/mL (P less than 0.01 vs. other stimuli)\].
We conclude that in children with short stature, as in adults,
enhancement of cholinergic tone increases both basal and GHRH-induced GH
secretion, and that PD plus GHRH is the best provocative stimulus for
evaluating the somatotroph response.

406\. Ghigo, E., *et al.*, *Effect of cholinergic enhancement by
pyridostigmine on growth hormone secretion in obese adults and
children.* Metabolism, 1989. 38(7): p. 631-3. In obesity the reduced
growth hormone (GH) responses to several provocative stimuli including
growth hormone-releasing hormone (GHRH) indicate a diminished
somatotroph responsiveness but do not distinguish between primary
pituitary and hypothalamic pathogenesis. However, it has been shown that
the cholinergic system positively influences Gh secretion likely by
modulating somatostatin release in a negative way. Thus, the effect of
cholinergic activity enhancement by pyridostigmine (PD), an
acetylcholinesterase inhibitor, on both basal and GHRH-induced GH
secretion was studied in 14 obese subjects (eight adults and six
children). Eighteen nonobese subjects (seven adults and 11 children)
were studied as controls. In obese subjects the GHRH-induced GH increase
was lower than in controls (peak, mean +/- SEM, adults, 9.2 +/- 2.7 v
16.8 +/- 5.7 ng/mL; children, 8.0 +/- 0.8 v 20.3 +/- 4.6 ng/mL)
attaining statistical significance only in children group (P less than
.02). The PD-induced GH response in the two obese groups was similar to
that observed in relative controls (adults, 5.3 +/- 1.0 v 7.4 +/- 1.7
ng/mL; children, 9.6 +/- 1.6 v 13.3 +/- 1.4 ng/mL). PD clearly
potentiated the GH response to GHRH in obese subjects, both adults (P
less than .05 v GHRH alone) and children (P less than .0005 v GHRH
alone). However, the GH responses to PD + GHRH was significantly reduced
in obese subjects compared with controls (adults, 18.1 +/- 2.2 v 42.7
+/- 10.7 ng/mL, P less than .05; children, 28.3 +/- 4.5 v 58.2 +/- 7.7
ng/mL, P less than .01). In conclusion, PD is able to potentiate the
blunted GH responses to GHRH in obese adults and children, inducing a GH
increase similar to that observed after GHRH alone in normal subjects.
This finding suggests that an alteration of somatostatinergic tone could
be involved in the reduced GH secretion in obesity.

407\. Ghigo, E., *et al.*, *Acute administration of pyridostigmine and
clonidine has an additive stimulatory effect on GH release in normal
children.* J Endocrinol Invest, 1989. 12(2): p. 99-101. It has been
shown in humans that both alpha 2-adrenoceptor activation by clonidine
(CLON) and cholinergic enhancement by pyridostigmine (PD) have a
clear-cut stimulatory effect on GH release. As this effect is probably
mediated by two different mechanisms, i.e. via increased endogenous GHRH
for CLON and via inhibition of endogenous somatostatin for PD, in 8
normal children we studied the effect of both single and combined acute
oral administration of CLON (150 micrograms/m2) and PD (60 mg). When
administered alone, CLON and PD induced a similar GH increase (peak,
mean +/- SE: 14.6 +/- 2.4 vs 14.2 +/- 3.1 ng/ml; area under curve, AUC:
376.9 +/- 57.6 vs 390.0 +/- 74.3 ng/ml/h). Combined administration of
CLON and PD had an additive effect on GH release (peak: 27.5 +/- 4.5
ng/ml; AUC: 920.8 +/- 153.3 ng/ml/h; p less than 0.005 vs CLON and PD
alone). In conclusion, presented data show that: i) CLON and PD have
similar GH-releasing effect in normal children; ii) The additive
stimulatory effect on GH release exerted by acute combined
administration of CLON and PD agrees with the hypothesized different
mechanism of action of these two drugs; iii) A therapeutic association
of CLON and PD may be envisaged in the treatment of some children of
short stature.

408\. Ghigo, E., *et al.*, *Cholinergic enhancement of pyridostigmine
potentiates spontaneous diurnal but not nocturnal growth hormone
secretion in short children.* Neuroendocrinology, 1989. 49(2): p. 134-7.
It has been shown that enhanced cholinergic tone induced by
pyridostigmine (PD) increases both basal and GHRH-stimulated GH levels
in both adults and children. In this study the effects of PD (60 mg
orally) on GH secretion were studied both in the morning (from 8.00 to
12.00) and in the night (from 23.00 to 3.00) in 7 short children
previously shown as having a normal spontaneous nocturnal GH secretion.
In the morning, PD induced a GH increase higher than saline (peak, mean
+/- SEM: 17.4 +/- 3.4 vs. 5.5 +/- 3.0 ng/ml, p less than 0.02; area
under curve (AUC): 360.8 +/- 71.4 vs. 109.4 +/- 44.7 ng/ml/h, p less
than 0.01). In the night, no difference was observed between GH
secretion after PD (peak: 16.7 +/- 2.4 ng/ml; AUC: 468.2 +/- 95.5
ng/ml/h) and saline (peak: 16.0 +/- 2.7 ng/ml; AUC: 409.1 +/- 97.7
ng/ml/h). Spontaneous GH secretion was higher during the night than in
the morning (p less than 0.02) whereas nocturnal GH secretion overlapped
with that in the morning after PD. The ability of PD to increase GH
secretion during the morning but not GH hypersecretion occurring at
night implies that the cholinergic tone in the central nervous system
areas controlling GH secretion is already maximally stimulated at night.
Since, reportedly, the cholinergic system negatively modulates
somatostatin secretion, presence of a physiologically reduced
somatostatinergic tone may be envisaged at night.

409\. Ghigo, E., *et al.*, *Pyridostigmine partially restores the GH
responsiveness to GHRH in normal aging.* Acta Endocrinol (Copenh), 1990.
123(2): p. 169-73. In 11 elderly normal subjects and in 17 young healthy
subjects we studied the response of plasma growth hormone to
GH-releasing hormone (GHRH(29), 1 microgram/kg iv) alone and preceded by
pyridostigmine (120 mg orally 60 min before GHRH), a cholinesterase
inhibitor likely able to suppress somatostatin release. The GH response
to pyridostigmine alone was also examined. Basal plasma GH levels were
similar in elderly and young subjects. In the elderly, GHRH induced a GH
rise (AUC, median and range: 207.5, 43.5-444.0 micrograms.l-1.h-1) which
was lower (p = 0.006) than that observed in young subjects (548.0,
112.5-2313.5 micrograms.l-1.h-1). The pyridostigmine-induced GH rise in
the elderly was similar to that in young subjects (300.5, 163.0-470.0 vs
265.0, 33.0-514.5 micrograms.l-1.h-1). Pyridostigmine potentiated the GH
responsiveness to GHRH in both elderly (437.5, 152.0-1815.5
micrograms.l-1.h-1; p = 0.01 vs GHRH alone) and young subjects (2140.0,
681.5-4429.5 micrograms.l-1.h-1; p = 0.0001 vs GHRH alone). However, the
GH response to pyridostigmine + GHRH was significantly lower (p =
0.0001) in elderly than in young subjects. In conclusion, the
cholinergic enhancement by pyridostigmine is able to potentiate the
blunted GH response to GHRH in elderly subjects, inducing a GH increase
similar to that observed after GHRH alone in young adults. This finding
suggests that an alteration of somatostatinergic tone could be involved
in the reduced GH secretion in normal aging. However, a decreased GH
response to combined administration of pyridostigmine and GHRH in
elderly subjects suggests that other abnormalities may coexist, leading
to the secretory hypoactivity of somatotropes.

410\. Ghigo, E., *et al.*, *Pyridostigmine potentiates L-dopa- but not
arginine- and galanin-induced growth hormone secretion in children.*
Neuroendocrinology, 1990. 52(1): p. 42-5. The coadministration of growth
hormone (GH) secretagogues can provide insight into the neuroregulation
of GH secretion. The GH response to L-dopa (125, 250 and 500 mg orally
for body weights less than 15 kg, between 15 and 30 kg and greater than
30 kg, respectively), arginine (Arg; 0.5 g/kg infused intravenously over
30 min) and galanin (GAL; 15 micrograms/kg infused intravenously over 60
min) when administered alone or combined with pyridostigmine (PD; 60 mg
orally), a cholinergic agonist that likely acts via inhibition of
endogenous somatostatin secretion, was studied in children with familial
short stature. The GH-releasing effect of PD was also evaluated. In 8
children, PD and L-dopa when administered alone induced an equivalent GH
rise (area under the response curve, mean +/- SEM: 241.4 +/- 31.1 vs.
202.9 +/- 38.6 micrograms/l/h) while their coadministration had an
additive effect (435.4 +/- 41.4 micrograms/l/h; p less than 0.02 vs. PD
and L-dopa alone). On the contrary, in other 8 children, PD and Arg
induced similar GH increases either when administered alone (394.2 +/-
68.5 vs. 405.8 +/- 103.9 micrograms/l/h) or in combination (535.8 +/-
97.3 micrograms/l/h). GH increases almost superimposable were also
observed when PD and GAL were administered alone (405.2 +/- 72.3 vs.
412.6 +/- 94.1 micrograms/l/h) or in combination (537.9 +/- 139.0
micrograms/l/h) in other 7 children. These data show that the
enhancement of the cholinergic activity by PD increases the
L-dopa-induced GH release but fails to modify both Arg- and GAL-induced
GH release in short children.(ABSTRACT TRUNCATED AT 250 WORDS).

411\. Ghigo, E., *et al.*, *Arginine potentiates the GHRH- but not the
pyridostigmine-induced GH secretion in normal short children. Further
evidence for a somatostatin suppressing effect of arginine.* Clin
Endocrinol (Oxf), 1990. 32(6): p. 763-7. To investigate the mechanism
underlying the GH-releasing effect of arginine (ARG), we studied the
interactions of ARG (0.5 g/kg infused i.v. over 30 min) with GHRH (1
microgram/kg i.v.) and with pyridostigmine (PD, 60 mg orally) on GH
secretion in 15 children and adolescents with familial short stature
(5.1-15.4 years). In a group of eight subjects ARG induced a GH increase
not statistically different to that observed after GHRH (peak, mean +/-
SEM: 38.0 +/- 10.4 vs 64.0 +/- 14.4 mU/l). The combined administration
of ARG and GHRH led to GH levels (101 +/- 15.2 mU/l) higher than those
observed after GHRH (P less than 0.025) or ARG alone (P less than 0.001)
and overlapping with those recorded after combined PD and GHRH
administration (111 +/- 22.4 mU/l). In the other seven subjects, ARG and
PD administration induced a similar GH response either when administered
alone (25.2 +/- 13.6 and 27.8 +/- 4.0 mU/l, respectively) or in
combination (33.8 +/- 5.4 mU/l). In conclusion, our results show that in
children ARG administration potentiates GHRH- but not PD-induced GH
increase. These findings agree with the hypothesis that the GH-releasing
effect of both ARG and PD is mediated via the same mechanism, namely, by
suppression of endogeneous somatostatin release. Combined administration
of either ARG or PD with GHRH has a similar striking GH-releasing effect
which is clearly higher than that of GHRH alone.

412\. Ghigo, E., *et al.*, *A new test for the diagnosis of growth
hormone deficiency due to primary pituitary impairment: combined
administration of pyridostigmine and growth hormone-releasing hormone.*
J Endocrinol Invest, 1990. 13(4): p. 307-16. The diagnosis of growth
hormone (GH) deficiency (GHD) is currently based on failure to increase
plasma GH levels to an arbitrary cutoff point of 7 or 10 micrograms/l in
response to two provocative stimuli. False negative responses to these
tests, however, frequently occur thus reducing their diagnostic
reliability. The aim of this study was to assess a combination of
pyridostigmine (PD) and GH-releasing hormone (GHRH) (60 mg oral PD 60
min before 1 microgram/Kg GHRH iv) as a reliable test probing pituitary
somatotropic function. In fact PD, an acetylcholinesterase inhibitor,
strikingly potentiates GH response to GHRH likely by inhibiting
somatostatin release. The combination PD + GHRH was tested in normal
children and adolescents (NS, n = 27) and in a large group of short
children classified as having familial short stature (FSS, n = 24),
constitutional growth delay (CGD, n = 34) and GH deficiency (organic,
oGHD, n = 6; idiopathic, iGHD, n = 10). In all groups results obtained
by PD + GHRH were compared with those obtained by testing with GHRH,
clonidine (CLON) and PD alone and by studying spontaneous nocturnal GH
secretion over 8 hours. Assuming 7 micrograms/l as minimum normal GH
peak, a positive response occurred in only 18/24, 11/12 and 12/13 NS for
GHRH, CLON, and PD, respectively. In contrast even assuming a minimum
normal GH peak as high as 20 micrograms/l, PD + GHRH induced a positive
response in 27/27 NS all having a nocturnal GH mean concentration (MC)
greater than or equal to 3 micrograms/l. Therefore PD + GHRH test gave
no false negative responses and this was true not only in NS but even in
all FSS and CGD having a GH MC greater than or equal to 3 micrograms/l.
On the other hand, PD + GHRH induced a negative GH response in all oGHD
and in 8/10 iGHD patients. In the remaining two iGHD patients, PD + GHRH
demonstrated a normal pituitary GH reserve in spite of a GH MC less than
3 micrograms/l and low IGF-I level, thus pointing to a hypothalamic
pathogenesis for the GHD. Considering FSS and CGD children having a GH
MC less than 3 micrograms/l, PD + GHRH showed a primary pituitary GH
deficiency in 3/12 CGD with low plasma IGF-I levels. In conclusion, in
slowly growing children PD + GHRH test is the most reliable provocative
test for the diagnosis of primary pituitary GH deficiency being capable
to discriminate between an unequivocally normal and impaired
somatotropic function.(ABSTRACT TRUNCATED AT 400 WORDS).

413\. Ghigo, E., *et al.*, *Comparison of growth hormone-releasing
effect of growth hormone-releasing hormone, clonidine and pyridostigmine
in normal children and adolescents. GH-releasing effect of GHRH,
clonidine and pyridostigmine.* Panminerva Med, 1990. 32(1): p. 1-3. The
GHRH test has been proposed to replace conventional stimuli in the
diagnosis of GH deficiency. However the reliability of GHRH in
discriminating between normal and GH-deficient children is still
uncertain. The aim of this study was to compare the GH-releasing effect
of GHRH (1 microgram/kg i.v.) with that of two neuroactive drugs,
clonidine (CLON, 150 micrograms/m2 orally), an alpha 2-receptor agonist,
and pyridostigmine (PD, 60 mg orally), a cholinergic agonist that
inhibits cholinesterases, in 23 children and adolescents with normal and
familial short stature. The plasma GH peak (mean +/- SEM) after GHRH
(20.3 +/- 2.5 ng/ml), CLON (17.0 +/- 2.1 ng/ml) and PD (14.9 +/- 1.5
ng/ml) did not significantly differ. According to the conventional limit
(less than 10 ng/ml), a false negative response was present in 6, 5 and
6 subjects after GHRH, CLON and PD, respectively. In conclusion, GHRH,
CLON and PD have a similar GH-releasing effect. A similar percentage of
false negative responses was observed with all tests and this evidence
reduces their diagnostic ability.

414\. Ghigo, E., *et al.*, *Failure of pyridostigmine to increase both
basal and GHRH-induced GH secretion in the night.* Acta Endocrinol
(Copenh), 1990. 122(1): p. 37-40. The aim of this study was to verify
that the stimulatory effect of cholinergic agonists on both basal and
stimulated GH release observed in the morning persists in the night. The
effects of pyridostigmine (120 mg orally), a cholinesterase inhibitor,
on both basal and GHRH (1 micrograms/kg iv)-induced GH secretion were
studied in 8 healthy volunteers, aged 22-30 years. In the morning,
administration of pyridostigmine induced a significant increase in basal
GH levels compared with saline (area under the response curve, mean +/-
SEM: 277.0 +/- 54.0 vs 49.7 +/- 8.2 micrograms.l-1.h-1, p less than
0.02) as well as a strong potentiation of the GHRH-induced GH release
(2117.6 +/- 353.0 vs 427.9 +/- 87.0 micrograms.l-h-1, p less than 0.02).
In the night, GH secretion after pyridostigmine did not differ from
saline (194.5 +/- 21.9 vs 89.4 +/- 28.7 micrograms.l-1.h-1). Moreover
pyridostigmine failed to potentiate the GHRH-induced GH increase (1071.9
+/- 170.4 vs 740.2 +/- 150.9 micrograms.l-1.h-1). The pyridostigmine +
GHRH-induced GH rise during the night was lower (p less than 0.05) than
in the morning. All together, these data seem to indicate that
cholinergic neurons controlling GH secretion are already maximally
stimulated at night. As cholinergic activity negatively modulates SRIH
secretion, our findings suggest that a reduced somatostatinergic tone in
the hypothalamus is present during the night.

415\. Ghigo, E., *et al.*, *Growth hormone secretion in Alzheimer\'s
disease: studies with growth hormone-releasing hormone alone and
combined with pyridostigmine or arginine.* Dementia, 1993. 4(6): p.
315-20. There is evidence that GH secretion is reduced in normal elderly
subjects as well as in patients with Alzheimer\'s disease (AD). To
clarify the mechanisms underlying this GH hyposecretory state in 14
elderly subjects (age 65-75 years) and 15 AD patients (age 61-78 years),
we studied the effects of both pyridostigmine (PD, 120 mg orally), a
cholinesterase inhibitor, and arginine (ARG, 0.5 g/kg i.v.), two
substances likely acting via inhibition of hypothalamic somatostatin, on
GH response to GHRH (1 microgram/kg i.v.). The GH response to PD alone
was also studied. Twenty-two young healthy volunteers were studied as
control group. Basal GH levels were similar in young, elderly and AD
subjects (0.7 +/- 0.2, 0.8 +/- 0.2 and 0.9 +/- 0.2 microgram/l). IGF-I
levels were lower (p \< 0.005) in elderly (73.9 +/- 8.2 microgram/l) and
in AD subjects (108.0 +/- 5.9 micrograms/l) than in young subjects
(288.7 +/- 22.1 micrograms/l); however, they were higher (p \< 0.01) in
AD patients than in the elderly subjects. The PD-induced GH release did
not significantly differ in young, elderly and AD subjects while the GH
responses to GHRH in the elderly (AUC: 297.9 +/- 49.2 micrograms/l) and
in AD subjects (437.6 +/- 93.5 micrograms/l/h) were lower (p \< 0.01)
than in young subjects (658.6 +/- 100.1 micrograms/l/h). PD potentiated
the GH response to GHRH both in elderly and in AD subjects (901.7 +/-
222.4 and 1,070.3 +/- 207.2 micrograms/l/h, p \< 0.005) but these
responses were lower (p \< 0.0001) than those recorded in young subjects
(2,041.1 +/- 245.6 micrograms/l/h).(ABSTRACT TRUNCATED AT 250 WORDS).

416\. Ghigo, E., *et al.*, *Arginine but not pyridostigmine, a
cholinesterase inhibitor, enhances the GHRH-induced GH rise in patients
with anorexia nervosa.* Biol Psychiatry, 1994. 36(10): p. 689-95.
Pirenzepine, a muscarinic antagonist probably acting via stimulation of
hypothalamic somatostatin release, abolishes the growth hormone
releasing hormone (GHRH)-stimulated growth hormone (GH) rise in normal
subjects but only blunts it in patients with anorexia nervosa (AN). This
finding suggested the existence in AN of an alteration of cholinergic
system and/or somatostatinergic tone. To further investigate these
mechanisms, in 11 AN women patients (age 18.8 +/- 0.9 years; BMI 13.4
+/- 0.4) we studied the GH response alone (1 microgram/Kg IV as a bolus
at 0 min) and combined with pyridostigmine (PD, 120 mg orally, 60 min
before GHRH administration), a cholinesterase inhibitor, or arginine
(ARG 30 g infused over 30 min starting at 0 min), two compounds probably
acting via inhibition of hypothalamic somatostatin (SS) release. The GH
response to GHRH preceded by a previous (120 min before) neurohormone
administration also was studied. All these tests also were performed in
20 normal age-matched women (age 22.0 +/- 1.8 yrs; BMI20.1 +/- 2.4).
Basal serum GH levels were higher in AN patients than in normal
volunteers (NV) (10.3 +/- 3.4 versus 2.8 +/- 0.3 microgram/L; p \<
0.001), whereas plasma IGF-I levels were lower in AN patients than in NV
(43.3 +/- 10.6 versus 172.4 +/- 13.9 micrograms/L; p \< 0.00001). In AN
patients, GHRH administration induced a GH rise higher, though not
significantly, than that in NV \[delta area under the curve (AUC) 1173.6
+/- 167.6 versus 834.6 +/- 188.1 micrograms/L/h\]. The GH response to
the second of two consecutive GHRH boluses was lower (p \< 0.01) than
that of the first one either in AN patients or in NV (67.6 +/- 27.4 and
53.1 +/- 25.7 micrograms/L/h, respectively).(ABSTRACT TRUNCATED AT 250
WORDS).

417\. Ghigo, E., *et al.*, *Interaction of salbutamol with
pyridostigmine and arginine on both basal and GHRH-stimulated GH
secretion in humans.* Clin Endocrinol (Oxf), 1994. 40(6): p. 799-802.
OBJECTIVE: It is well known that acetylcholine and arginine stimulate GH
secretion while activation of beta-adrenergic receptors inhibits GH
secretion in man. We aimed therefore to ascertain whether or not the
inhibitory influence of beta-adrenergic receptors on GH secretion would
over-ride the stimulatory one of acetylcholine and arginine. DESIGN: We
studied the interaction of salbutamol, a beta 2-adrenergic agonist (SAL,
0.08 mg/kg orally) with pyridostigmine, a cholinesterase inhibitor (PD,
120 mg orally), or arginine (0.5 g/kg i.v.) on both basal and GHRH (1
microgram/kg i.v.)-stimulated GH secretion. SUBJECTS: Fourteen healthy
male volunteers, aged 20-35 years, were studied. MEASUREMENTS: Serum GH
was measured in duplicate by immunoradiometric assay. RESULTS: In study
A, SAL inhibited the GH response both to GHRH (P \< 0.01) and ARG (P \<
0.002). ARG enhanced the GHRH-induced GH rise (P \< 0.01) but its effect
was abolished (P \< 0.02) by SAL pretreatment. In study B, SAL inhibited
the GH response both to GHRH (P \< 0.01) and PD (P \< 0.02). PD enhanced
the GH response to GHRH (P \< 0.001) but its effect was abolished (P \<
0.05) by SAL pretreatment. In both studies, the GH response to GHRH
alone was similar to that to the neurohormone when combined with ARG +
SAL or PD + SAL. CONCLUSION: Our results show that beta 2-adrenergic
activation by salbutamol is able to inhibit not only the GH rise induced
by GHRH, arginine and pyridostigmine, but even the potentiating effect
of both arginine and pyridostigmine on the GH response to GHRH. They
indicate that catecholamines, acetylcholine and arginine play a major
role in GH secretion having opposite influences aimed to balance the
function of the hypothalamus-GH-IGF-I axis in man.

418\. Giusti, M., *et al.*, *Growth hormone secretion in aging. Effect
of pyridostigmine on growth hormone responsiveness to growth
hormone-releasing hormone.* Recenti Prog Med, 1991. 82(12): p. 665-8.
Recent studies in adults have shown that cholinergic enhancement by
pyridostigmine (PD) has a stimulatory effect on growth hormone (GH)
response to GH-releasing hormone (GHRH). PD probably reduces
somatostatin release from the hypothalamus by increasing the central
cholinergic tone. The aim of this study was to evaluate the effect of PD
(120 mg orally) or placebo pretreatment on GH responsiveness to GHRH (1
micrograms/kg b.w. i.v.) or placebo in 10 normal elderly males (68-92
years). PD induced a significant increase in GH secretion (GH peak 7.3
+/- 1.8 micrograms/L, mean +/- SEM) over the basal value (0.9 +/- 0.2
micrograms/L; P less than 0.01) and enhanced GH response to GHRH (peak
after GHRH: 17.0 +/- 3.8 micrograms/L; after PD plus GHRH: 42.6 +/- 12.2
micrograms/L; P less than 0.05). There was a significant difference in
the secretory areas of GH among tests (P less than 0.05). The secretory
area was greater after PD plus GHRH (2722 +/- 801 micrograms/L/120 min)
than after GHRH (1185 +/- 206 micrograms/L 120 min; P less than 0.01).
The effect of PD on GH secretion suggests that cholinergic mechanisms
may be involved in GH control in normal aging. During the life-span
cholinergic neurons and/or the somatostatin pathways could exert a
differential effect on GH control.

419\. Giustina, A., *et al.*, *Impaired growth hormone (GH) response to
pyridostigmine in type 1 diabetic patients with exaggerated GH-releasing
hormone-stimulated GH secretion.* J Clin Endocrinol Metab, 1990. 71(6):
p. 1486-90. In the present study we investigated the effects of the
acetylcholinesterase inhibitor pyridostigmine (PD), which is
hypothesized to decrease hypothalamic somatostatin tone, alone and in
association with GH-releasing hormone (GHRH) on GH secretion in 18 type
1 diabetic patients and 12 normal subjects using a randomized double
blind placebo-controlled protocol. All subjects received either 120 mg
oral PD or placebo 60 min before iv injection of either human
GHRH-(1-29) NH2 (100 micrograms) or sterile water (2 mL). In normal
subjects both PD alone and GHRH alone caused a significant increase in
GH. PD and GHRH acted in a synergistic fashion when combined. In
diabetic patients the GH response to GHRH was variable. To segregate the
responses, the ratio between the GH increase after GHRH plus PD and
after GHRH alone was calculated for each subject. In 10 diabetic
patients (group A) the ratio was lower than 2 SD (P less than 0.05) from
the mean response of normal subjects. These patients showed an
exaggerated GH increase after GHRH and a lower GH increase after PD with
respect to normal subjects. Eight diabetic patients (group B) showed a
ratio similar to that in normal subjects and similar GH responses to the
stimuli. No significant differences were found between groups A and B
with respect to age, body mass index, and blood glucose levels. Duration
of diabetes was longer and basal GH levels were higher in group A.
Hemoglobin-A1c was higher in group A, but of only borderline statistical
significance (P = 0.052). Our data demonstrate that in diabetic patients
with exaggerated GH responses to GHRH an increase in cholinergic tone
does not affect GH secretion. These data suggest that in some type 1
diabetic patients an altered somatostatinergic control of GH secretion
may contribute to their abnormal GH response to GHRH.

420\. Giustina, A., *et al.*, *Effects of calcitonin on GH response to
pyridostigmine in combination with hGHRH (1-29) NH2 in normal adult
subjects.* Clin Endocrinol (Oxf), 1990. 33(3): p. 375-80. Studies in man
demonstrated that salmon calcitonin (sCT) administration blunts the
pituitary GH response to GH-releasing hormone (GHRH). However, the
mechanisms underlying this inhibitory action of CT in man are unclear.
Pyridostigmine (PD), an acetylcholinesterase inhibitor, is hypothesized
to enhance the GH response to GHRH in normal subjects probably via a
decrease in the somatostatinergic tone. The aim of the present study was
to investigate the mechanism of the inhibitory action of sCT on the GH
response to human GHRH (1-29) NH2 by concomitant PD administration in
normal humans. The GH response to GHRH was significantly suppressed by
prior administration of sCT. Pretreatment of subjects with PD
significantly enhanced the GH response to GHRH but did not alter the
inhibitory actions of sCT. We conclude that sCT is able to inhibit
GHRH-stimulated GH secretion in man without influencing the hypothalamic
somatostatinergic tone.

421\. Giustina, A., *et al.*, *Pyridostigmine blocks the inhibitory
effect of glucocorticoids on growth hormone-releasing hormone stimulated
growth hormone secretion in normal man.* J Clin Endocrinol Metab, 1990.
71(3): p. 580-4. Glucocorticoids have been shown to inhibit GH secretion
in normal man when acutely and chronically administered in
pharmacological amounts. Pyridostigmine (PD), an acetylcholinesterase
inhibitor, is able to elicit GH secretion when administered alone and to
enhance the GH response to GHRH in normal subjects probably via a
decrease in the hypothalamic release of somatostatin. The aim of the
present study was to investigate the influence of glucocorticoids on the
GH response to PD administered either alone or in combination with GHRH
in normal adult subjects. Six healthy adult volunteers underwent six
experimental protocols. They received 1) human (h) GHRH(1-29)NH2, 100
micrograms injected as an iv bolus; 2) cortisone acetate, 50 mg
administered orally (po) 60 min before an hGHRH iv bolus injection; 3)
PD, 120 mg administered po, 60 min before an hGHRH iv bolus injection;
4) PD and cortisone acetate, administered po 60 min before an hGHRH iv
bolus injection; 5) PD, administered po 60 min before a saline iv bolus
injection; 6) PD and cortisone acetate administered po 60 min before a
saline iv bolus injection. Mean GH levels, peak GH levels, and GH area
under the curves (AUCs) were significantly lower after GHRH + cortisone
as compared to GHRH alone. However, these parameters were not
significantly different after PD + GHRH + cortisone when compared to
PD + GHRH and after PD + cortisone when compared to PD alone. We
conclude that acute administration of pharmacological amounts of
glucocorticoids cannot inhibit the GH response to PD alone or in
combination with GHRH. Thus, we hypothesize that the inhibitory action
of glucocorticoids on the GH response to GHRH in man may be mediated by
an enhancement of either somatostatin release by the hypothalamus or
somatostatin action on the pituitary.

422\. Giustina, A., *et al.*, *Effects of pyridostigmine on spontaneous
and growth hormone-releasing hormone stimulated growth hormone secretion
in children on daily glucocorticoid therapy after liver
transplantation.* Clin Endocrinol (Oxf), 1991. 35(6): p. 491-8.
OBJECTIVES: We aimed to investigate both nocturnal spontaneous and
morning growth hormone (GH)-releasing hormone (GHRH)-induced GH
secretion in children on daily glucocorticoid treatment after liver
transplantation and to evaluate the effect of pyridostigmine (an
acetylcholinesterase inhibitor thought to reduce hypothalamic
somatostatin tone) on GH secretion in these patients. DESIGN: We
performed a randomized, single-blind, cross-over study. PATIENTS: We
studied three male and three female juvenile patients, within a year of
orthotopic liver transplantation and under immunosuppressive
glucocorticoid therapy (mean dose +/- SEM, 5.92 +/- 0.63 mg/day) and
five normal children (four males, one female). MEASUREMENTS: Both
nocturnal spontaneous and morning GHRH-induced GH secretion were
evaluated after administration of placebo, 1 tablet p.o., or
pyridostigmine, 2 mg/kg p.o. RESULTS: Spontaneous GH. Placebo: in liver
transplanted children nocturnal GH secretion (mean GH level 10.8 +/- 2.0
mU/l) was not significantly different with respect to normal children
(mean GH level 12.8 +/- 1.2 mU/l); pyridostigmine: nocturnal GH
secretion was significantly increased as compared to placebo in subjects
with liver transplantation but not in normal children. GHRH test.
Placebo: liver transplanted patients showed a blunted GH response to
GHRH with respect to normal children; pyridostigmine: the GH responses
to GHRH (P less than 0.05) increased as compared to placebo and did not
differ significantly in the two groups. CONCLUSIONS: Our data suggest a
steroid-mediated increase in hypothalamic somatostatin tone in liver
transplanted children.

423\. Giustina, A., *et al.*, *Effects of exogenous growth hormone
pretreatment on the pituitary growth hormone response to growth
hormone-releasing hormone alone or in combination with pyridostigmine in
type I diabetic patients.* Acta Endocrinol (Copenh), 1991. 125(5): p.
510-7. We evaluated the effects of iv pretreatment with exogenous GH on
the GH response to GHRH either alone or in combination with
pyridostigmine in 14 Type I diabetic patients and 6 normal subjects. All
the subjects received an iv bolus injection of biosynthetic human GH, 2
IU; 2 h later they received either a. pyridostigmine, 120 mg orally, or
b. placebo, 2 tablets orally, followed 1 h later by iv injection of
GHRH(1-29) NH2, 100 micrograms. In normal subjects the median GH peak
after GH+ GHRH was 1.8, range 1.2-6.9 micrograms/l. Pyridostigmine
enhanced the GH response to GHRH in all subjects. The median GH peak
after pyridostigmine + GH + GHRH was 32.7, range 19.8-42.1 micrograms/l
(p less than 0.001 vs GHRH alone). Seven diabetic subjects had median GH
peaks after GH + GHRH greater than 6.9 micrograms/l (the maximum GH peak
after GH + GHRH in normal subjects) (group A: median GH peak 35.7, range
21.7-55 micrograms/l). The other diabetic subjects had GH peak lower
than 6.9 micrograms/l (group B: median GH peak 4.4, range 2.1-6.5
micrograms/l). Pyridostigmine significantly increased the GH response to
GHRH in group B patients (median GH peak 29.3, range 15.7-93.4
micrograms/l, p less than 0.001 vs GH + GHRH alone), but not in group A
patients (median GH peak 39.9, range 21.9-64.9 micrograms/l). Group A
diabetic patients were younger and had higher HbA1c and blood glucose
levels than group B patients. In those diabetic patients with an
exaggerated GH response to GH + GHRH, pyridostigmine failed to cause the
increase in GH secretion observed in diabetic and control subjects with
no responses to GH + GHRH.(ABSTRACT TRUNCATED AT 250 WORDS).

424\. Giustina, A., *et al.*, *Pyridostigmine enhances even if it does
not normalize the growth hormone responses to growth hormone-releasing
hormone in patients with Cushing\'s disease.* Horm Res, 1991. 35(3-4):
p. 99-103. Subjects with Cushing\'s disease have diminished growth
hormone (GH) response to growth hormone-releasing hormone (GHRH). The
aim of our study was to investigate the underlying mechanism of this
diminished GH response in these patients using pyridostigmine (PD), an
acetylcholinesterase inhibitor, which is reported to increase GH
secretion by reducing somatostatin tone. Eight subjects with untreated
Cushing\'s disease (caused by a pituitary adenoma) and 6 control
subjects received GHRH 100 micrograms in 1 ml of saline, as intravenous
bolus injection 60 min after (1) placebo (2 tablets, p.o.) or (2) PD
(120 mg, p.o.). After GHRH plus placebo, the GH peak (mean +/- SEM) was
significantly lower in subjects with Cushing\'s disease (2.4 +/- 0.5
micrograms/l) compared to control subjects (25.1 +/- 1.8 micrograms/l, p
less than 0.05). After GHRH plus PD, the GH peak was significantly
enhanced both in subjects with Cushing\'s disease (7.1 +/- 2.3
micrograms/l, p less than 0.05) and in control subjects (42.3 +/- 4.3
micrograms/l, p less than 0.05). In patients with Cushing\'s disease,
the GH response to GHRH plus PD was lower with respect to the GH
response to GHRH alone in normal subjects. We conclude that
hypercortisolism may cause a decrease in central cholinergic tone which
is in turn hypothesized to be responsible of an enhanced somatostatin
release from the hypothalamus. However, other metabolic or central
nervous system alterations may act synergistically with hypercortisolism
in causing GH inhibition in patients with Cushing\'s disease.

425\. Giustina, A., *et al.*, *Comparative effect of galanin and
pyridostigmine on the growth hormone response to growth
hormone-releasing hormone in normal aged subjects.* Horm Res, 1992.
37(4-5): p. 165-70. The aim of our study was to investigate the effects
of aging on the growth hormone (GH) response to growth hormone-releasing
hormone (GHRH) alone and in combination with either the neuropeptide
galanin or the acetylcholinesterase inhibitor pyridostigmine (PD) in
normal subjects. In protocol 1 (GHRH/galanin), 9 old healthy volunteers,
ranging in age from 68 to 97 years, and 6 young subjects, ranging in age
from 25 to 31 years, received: (a) human GHRH (1-29)NH2, 100 micrograms
in 1 ml saline, as an intravenous bolus, and (b) porcine galanin, 500
micrograms in 100 ml saline, as an intravenous infusion from -10 to 30
min combined with GHRH, 100 micrograms i.v. at time 0. In protocol 2
(GHRH/PD), 14 old healthy volunteers, ranging in age from 65 to 91
years, and 11 young subjects, ranging in age from 19 to 34 years,
received: (a) GHRH (1-29)NH2, 100 micrograms in 1 ml saline, as an
intravenous bolus, and (b) PD, 120 mg administered per os 60 min before
GHRH, 100 micrograms as an intravenous bolus. Blood samples for GH were
drawn at -75, -60 (time of PD administration), -45, -30, -15, -10 (time
of beginning of galanin infusion), 0 (time of GHRH injection), 15, 30,
45, 60, 90, and 120 min. The GH response to GHRH was significantly (\<
0.05) enhanced either by galanin or PD pretreatment both in young and
old subjects. However, the GH response to GHRH alone or combined with
either galanin or PD was significantly greater in the young subjects as
compared to the old subjects.(ABSTRACT TRUNCATED AT 250 WORDS).

426\. Giustina, A., *et al.*, *Variability in the growth hormone
response to growth hormone-releasing hormone alone or combined with
pyridostigmine in type 1 diabetic patients.* J Endocrinol Invest, 1993.
16(8): p. 585-90. In man the GH response to GHRH is variable within and
between subjects. Pyridostigmine (PD), an acetylcholinesterase
inhibitor, has been shown to reduce the variability of the GH response
to GHRH in normal subjects. The aim of this study was to assess the
existence of either inter- or intraindividual variability in the GH
response to GHRH in type 1 diabetic patients. Moreover, we investigated
the effect of PD on such variability in the same patients. Seven (4
females-3 males) nonobese type 1 diabetic patients underwent two
experiments performed in consecutive days according to a single-blind
protocol: 1) 120 mg oral PD 60 min before iv injection of human (h)
GHRH-(1-29) NH2, 100 micrograms in 2 ml of sterile water; 2) oral
placebo 60 min before iv injection of 100 micrograms hGHRH. The two
experiments were then repeated, following the same procedure, one and
two weeks after the start of the study. The GH peaks after GHRH were
variable within different subjects but also in the same subject on
different occasions. However, the mean GH peak levels after GHRH in the
three tests were not significantly different (14.2 +/- 3.5, 15.3 +/- 3,
16.5 +/- 6.4 micrograms/L, respectively), the coefficient of variation
for each test was 65%, 51.8%, 102.4%, respectively (mean 73.1 +/-
15.1%). The GH response to GHRH was always significantly enhanced by PD
administration: the mean GH peak levels in the three tests were 31.9 +/-
7.1, 44.8 +/- 10.4, 49.9 +/- 13.1 micrograms/L, respectively, without
significant differences between tests.(ABSTRACT TRUNCATED AT 250 WORDS).

427\. Giustina, A., *et al.*, *Effect of pyridostigmine on the growth
hormone response to growth hormone-releasing hormone in lean and obese
type II Diabetic patients.* Metabolism, 1994. 43(7): p. 893-8. A
suppressed growth hormone (GH) response to GH-releasing hormone (GHRH)
in both lean and overweight type II diabetics has been reported.
Pyridostigmine (PD), an acetylcholinesterase inhibitor, elicits GH
secretion when administered alone and enhances the GH response to GHRH
in normal subjects. The aim of our study was to evaluate the effect of
PD on GHRH-stimulated GH secretion in both lean and obese type II
diabetic patients. We studied 16 patients with type II diabetes mellitus
(seven lean and nine obese). Eleven nondiabetic subjects (six lean and
five obese) served as controls. Each subjects underwent treatment with
(1) 120 mg PD orally or (2) 2 tablets of placebo orally, 60 minutes
before intravenous (IV) injection of 100 micrograms GHRH-(1-29)NH2. We
have found no significant differences in GH responses to GHRH between
obese diabetics and obese controls. On the other hand, the absolute GH
levels were significantly suppressed in lean type II diabetics compared
with lean controls at 15 and 30 minutes after GHRH injection. Obese
diabetic subjects had slightly but not significantly decreased GH
responses to GHRH+PD compared with obese nondiabetic subjects (8.36 +/-
1.62 v 14.4 +/- 7.62 micrograms/L). Lean type II diabetics showed a
blunted GH release after GHRH+PD compared with normal-weight healthy
subjects (GH peaks, 15.77 +/- 2.17 v 40.88 +/- 6.17 micrograms/L, P \<
.05). PD enhanced significantly the GH response to GHRH in obese
diabetics, obese controls, and non-obese controls (P \< .05), but not in
non-obese type II diabetics.(ABSTRACT TRUNCATED AT 250 WORDS).

428\. Giustina, A., *et al.*, *Effect of pyridostigmine on the
hydrocortisone-mediated decrease of circulating growth hormone levels in
acromegaly.* Horm Metab Res, 1994. 26(6): p. 288-92. The aims of our
study were to investigate the effect of the acetylcholinesterase
inhibitor pyridostigmine (PD) administration on growth hormone (GH)
secretion in acromegaly and to investigate the effects of PD on GH
levels following an i.v. infusion of hydrocortisone in acromegaly. We
studied five adult patients with active acromegaly, three men and two
women with a mean age of 60 +/- 5 years (range 47-71 years) and a mean
BMI of 27 +/- 0.7 kg/m2 (range 24-28 kg/m2). All the patients
underwent: 1) placebo, 2 tablets po or 2) PD, 120 mg po, at time -60
plus a bolus i.v. injection of 100 mg hydrocortisone succinate in 2 ml
saline at time 0 followed by an i.v. infusion of 250 mg hydrocortisone
succinate in 250 ml saline from 0 to 120 min, or 3) PD, po or 4)
placebo, po at time -60 plus a bolus i.v. injection of 2 ml saline
followed by an i.v. infusion of 250 ml saline from 0 to 120 min. Serum
GH values did not significantly change after PD administration compared
to those during placebo treatment and with respect to baseline levels.
In all of the acromegalic patients during hydrocortisone succinate
infusion, GH values clearly decreased with respect to basal levels in
varying degrees, with a nadir between 90 and 180 minutes after the
beginning of hydrocortisone infusion.(ABSTRACT TRUNCATED AT 250 WORDS).

429\. Grugni, G., *et al.*, *Reduced growth hormone (GH) responsiveness
to combined GH-releasing hormone and pyridostigmine administration in
the Prader-Willi syndrome.* Clin Endocrinol (Oxf), 1998. 48(6): p.
769-75. OBJECTIVE: It is unclear whether the blunted GH secretion in
Prader-Willi Syndrome (PWS) is a true deficiency, or merely secondary to
obesity. We have investigated the role of obesity in the blunted GH
secretion in PWS. DESIGN: We studied the GH response to a combined
administration of GHRH (1 microgram/kg i.v. at 0 min) and pyridostigmine
(PD) (60 and 120 mg by mouth for children and adults, respectively, at
time -60 min), as well as the baseline IGF-I levels, in a group of
patients with PWS. Two different control groups were studied with GHRH +
PD using the same doses and methods as above: prepubertal and pubertal
obese subjects, and prepubertal short normal children. Moreover, in 14
patients with PWS and in the group of short normals the GH response to
at least two stimulation tests (insulin tolerance test, clonidine,
L-dopa, arginine) had been previously determined. PATIENTS: Twenty-two
PWS patients (10 males and 12 females), 21 with essential obesity (11
males and 10 females), and eight short normal children (4 males and 4
females) were studied after obtaining informed consent. MEASUREMENTS:
Blood samples were taken at -60, -30 and 0 min and then 15, 30, 45, 60,
90 and 120 min after GHRH administration. Serum GH was measured in
duplicate by IRMA, and IGF-I by RIA after acid ethanol extraction.
Statistical analysis was performed by t-test for unpaired data, and
analysis of variance for parametric or nonparametric data, where
appropriate. RESULTS: The GH response to GHRH + PD was significantly
lower in PWS patients (AUC: mean +/- SE: 599 +/- 99 micrograms/l/h) if
compared with either short normal children (3294 +/- 461 micrograms/l/h:
P \< 0.0001) or obese subjects (1445 +/- 210 micrograms/l/h: P \<
0.005). Low IGF-I concentrations were found in all PWS patients, so that
PWS group had mean IGF-I levels significantly lower than the other
groups. CONCLUSIONS: Our results showed that subjects with PWS had a
reduced GH responsiveness to GHRH + PD associated with subnormal IGF-I
levels. These findings suggested that short stature in PWS may be at
least partially correlated to the presence of GH deficiency, and that
impaired GH secretion is not secondary to obesity.

430\. Guzzaloni, G., *et al.*, *\[Effect of sex on the increase of GH
induced by galanin, alone or in combination with GHRH with or without
pyridostigmine in pubescent subjects\].* Minerva Endocrinol, 1996.
21(2): p. 53-7. Growth hormone response to galanin (GAL) and growth
hormone releasing hormone have been demonstrated to be higher in females
than in males, and moreover the cholinergic system appears to be able to
enhance them. On the basis of this presumption, we evaluated the GH
response (expressed as area under the curve: AUC-GH) to galanin (GAL, 10
mg/kg i.v.) or GHRH (1 mg/kg i.v.) either alone or associated together
and with pyridostigmine (PD, 60 mg p.o.), and to saline infusion as a
control, in 5 males and 5 females, in puberty, aged 16 +/- 0.4 years old
(mean +/- SD). In females tests were performed during the follicular
phase of the menstrual cycle. GAL alone cannot provoke a response from
GH unless associated with GHRH. The contemporary administration of PD
does not increase the extent of the response. The latter did not differ
between sexes. The GHRH-GAL association induced a higher response in GH
compared to GAL alone and GAL-PD, without any differences between the
sexes. Lastly, the combination GHRH-GAL-PD induced responses that were
comparable to GHRH and GAL alone. Therefore GAL does not act alone but
enhances the effect of GHRH and the cholinergic system appears to be
involved as a modulator. Moreover, the effect of GAL is comparable in
both sexes.

431\. Guzzaloni, G., G. Grugni, and F. Morabito, *Growth hormone
response to hexarelin, growth hormone-releasing hormone plus
pyridostigmine and arginine plus estrogen in prepubertal and early
pubertal short children.* Minerva Endocrinol, 1998. 23(4): p. 99-104.
BACKGROUND: Hexarelin (HEX), a synthetic hexapeptide with a strong
GH-stimulating activity, has been suggested as a stimulus for evaluating
GH secretion. However, in childhood it has never been compared with
other stimuli capable to reduce the effect of the somatostatinergic tone
and of the low production of gonadal steroids. METHODS: We evaluated GH
response (expressed as the maximum value after stimulus \[Cmax\] and as
area under the curve \[AUC\], mean +/- SD) to HEX at a dose of 2
micrograms/kg i.v., in comparison with those obtained after GHRH (1
microgram/kg i.v.) + pyridostigmine (PD, 60 mg p.o.) and arginine +
ethynylestradiol (E2, 1 mg/day p.o. for 3 days before the test), in 5
subjects with familial short stature (FSS), 11 with constitutional
growth delay (CGD), prepubertal (Tanner\'s stage I) and early pubertal
(stage II), and in 8 healthy children age-matched as controls. RESULTS:
HEX induced a Cmax of 31.9 +/- 18.4 micrograms/l and an AUC of 1511 +/-
923 micrograms/min x l in stage I, of 36.7 +/- 12.3 micrograms/l and
1938 +/- 903 micrograms/min x l in stage II (ns). GHRH + PD induced a
Cmax of 33.8 +/- 14.6 micrograms/l and an AUC of 2072 +/- 1233
micrograms/min x l in stage I, of 29.6 +/- 15.6 micrograms/l and 1901
+/- 1252 micrograms/min x l in stage II (ns). ARG + E2 induced a Cmax of
17.8 +/- 7 micrograms/l and an AUC of 1157 +/- 505 micrograms/min x l in
stage I, of 15.6 +/- 11.6 micrograms/l and 649 +/- 452 micrograms/min x
l in stage II (ns). The Cmax of HEX was higher than that of ARG + E2 in
both stages I and II (p \< 0.05); AUC of HEX, was higher than that of
ARG + E2 only in stage II (p \< 0.01); the Cmax and the AUC of GHRH + PD
were higher than those of ARG + E2 both in stage I (p \< 0.01 and p \<
0.05, respectively) and in stage II (p \< 0.05). No difference, neither
in the extent of GH response to HEX and GHRH + PD nor in that to stimuli
between subjects and controls, was found. HEX has given 32% false
positives in stage I and 17% in stage II, GHRH + PD 12% and 15%, while
ARG + E2 provided 20% in stage I and 32% in stage II. On the whole,
specificity was 76% for HEX and ARG + E2 and 89% for GHRH + PD.
CONCLUSIONS: HEX induced greater GH response than that of ARG + E2 but
similar to that of GHRH + PD and its specificity was not different to
that of ARG + E2 and lower than that of GHRH + PD: then its use does not
show a diagnostic advantage in respect to the other two stimuli in
peripubertal age.

432\. Guzzaloni, G., G. Grugni, and F. Morabito, *Hexarelin-induced
growth hormone response in short stature. Comparison with growth
hormone-releasing hormone plus pyridostigmine and arginine plus
estrogen.* J Endocrinol Invest, 1999. 22(5): p. 360-8. Hexarelin (HEX)
is a synthetic hexapeptide with strong GH-stimulating activity. We
evaluated GH response (expressed as maximum value after stimulus
\[Cmax\] and as area under the curve \[AUC\]) to HEX at the doses of 1
microg/kg i.v. (HEX 1) and 2 microg/kg i.v. (HEX 2), in comparison with
the responses to GHRH (1 microg/kg i.v.) + pyridostigmine (PD, 60 mg po)
and to arginine (ARG, 0.5 mg/kg i.v.) + ethinylestradiol (EE, 1 mg/day
po for 3 days before the stimulation), in 5 subjects with familial short
stature (FSS), 11 with constitutional growth delay (CGD), 6 with GH
neurosecretory dysfunction (NSD), and 5 with isolated growth hormone
deficiency (GHD). Cmax and AUC after HEX 1 were 26.8+/-10.5 ng/ml and
1448+/-514 ng/min x ml in FSS, 23.6+/-14.4 ng/ml and 1146+/-750 ng/min x
ml in CGD, 36.9+/-21.5 ng/ml and 2048+/-1288 ng/min x ml in NSD,
9.4+/-5.8 ng/ml and 498+/-200 ng/min x ml in GHD (Cmax and AUC in FSS
and CGD, p\<0.05 vs GHD). Cmax and AUC after HEX 2 were 37.7+/-16 ng/ml
and 1979+/-888 ng/min x ml in FSS, 32.5+/-16.2 ng/ml and 1613+/-237
ng/min x ml in CGD, 39.7+/-20.7 ng/ml and 2366+/-1569 ng/min xml in NSD,
13.4+/-4.2 ng/ml and 645+/-293 ng/min x ml in GHD (Cmax in FSS, CGD and
NSD p\<0.01 vs GHD; AUC in NSD, p\<05 vs GHD). Cmax and AUC after
GHRH+/-PD were 46.6+/-8.8 ng/ml and 3294+/-1031 ng/min x ml in FSS,
25.9+/-11.2 ng/ml and 1464+/-735 ng/min x ml in CGD, 38.8+/-21.7 ng/ml
and 2428+/-1399 ng/min x ml in NSD, 8.4+/-6.2 ng/ml and 685+/-572 ng/min
x ml in GHD (Cmax and AUC in FSS, p\<0.001 vs CGD and GHD; Cmax in CGD
and NSD, p\<0.001 vs GHD). Cmax and AUC after ARG+EE were 21.3+/-4.2
ng/ml and 1432+/-514 ng/min x ml in FSS, 14.8+/-10 ng/ml and 805+/-489
ng/min x ml in CGD, 22.2+/-12.8 ng/ml and 1199+/-309 ng/min x ml in NSD,
4.6+/-2.5 ng/ml and 247+/-191 ng/min x ml in GHD (Cmax and AUC in FSS,
CGD and NSD, p\<0.01 vs GHD). Specificity was 62% for HEX 1 and 75% for
HEX 2, GHRH+PD and ARG+EE. From a diagnostic point of view, HEX 1 + HEX
2 was the association with the largest percentage of false positives
(20% in FSS, 27% in CGD and 33% in NSD), HEX 1 +GHRH+PD resulted in 9%
in CGD, while the combined use of HEX 1 or HEX 2 with GHRH+PD or ARG+EE
and of GHRH+PD with ARG+EE did not show false positive responses. In
conclusion: I) the most effective dose of HEX was 2 microg/kg i.v.; 2)
HEX did not show more specificity than GHRH+PD and ARG+EE; 3) the
association of GHRH+PD with ARG+EE could yield the best results at lower
costs, confirming these tests as first-line tools in evaluating GH
secretion.

433\. Hanew, K., *et al.*, *The evaluation of hypothalamic somatostatin
tone using pyridostigmine and thyrotropin releasing hormone in patients
with acromegaly.* J Endocrinol Invest, 1994. 17(5): p. 313-21. To
indirectly evaluate the hypothalamic somatostatin (SS) tone in patients
with acromegaly, the effects of pyridostigmine (PD), a cholinesterase
inhibitor which can inhibit hypothalamic SS secretion, on TRH-induced
TSH secretion and the effects of SMS 201-995 on TSH or GH secretion were
studied in acromegalic patients (31-69 yr, n = 10), normal young (21-24
yr, n = 7) and normal old male subjects (62-71 yr, n = 7). After
pretreatment with PD (60 mg po, -30 min), normal young subjects showed
significantly enhanced TSH responses to TRH (500 micrograms i.v., 0 min)
compared to single administration of TRH, whereas normal old and
acromegalic patients did not show such enhancement. Plasma TSH response
to a single administration of TRH in acromegalic patients was
significantly lower than that of normal young and old subjects. Although
normal young and old subjects showed significantly enhanced GH responses
to GHRH (100 micrograms i.v. at 0 min) after the pretreatment with PD
(60 mg, -30 min), no such enhancement was observed in acromegalic
patients. In contrast, the decrement in plasma TSH after SMS 201-995
administration was similar between normal subjects (5 young 5 old) and 7
acromegalic patients. Further, the maximal plasma GH decrement after
administration was significantly greater in acromegalic patients than in
the 5 normal young and 5 old subjects p \< 0.01). In conclusion,
hypothalamic SS tone does not appear to be elevated in acromegalic
patients compared to normal young and probably old subjects.

434\. Hanew, K., A. Tanaka, and A. Utsumi, *Plasma GH responses to GHRH,
arginine, L-dopa, pyridostigmine, sequential administrations of GHRH and
combined administration of PD and GHRH in Turner\'s syndrome.* J
Endocrinol Invest, 1998. 21(2): p. 72-7. To investigate GH secretory
capacities in patients with Turner\'s syndrome, GHRH, arginine, L-dopa
and pyridostigmine (PD) were administered singly and GHRH was
administered sequentially for 3 days. In addition, plasma GH and TSH
responses to GHRH and TRH after pretreatment with PD were analyzed to
investigate whether the hypothalamic cholinergic somatostatinergic
system functioned normally. The maximal GH responses to GHRH, L-dopa and
PD were significantly smaller in Turner\'s syndrome (no.=14) than in
normal short children (NSC, no.=14). However, there was no difference in
plasma GH responses to arginine between the two groups. In ten patients
with Turner\'s syndrome, the plasma GH response to GHRH did not improve
even after the sequential 3-day administrations. Although plasma GH and
TSH responses to GHRH and TRH were significantly enhanced by the
pretreatment of PD in NSC (no.=12), these responses were not enhanced in
Turner\'s syndrome. Plasma GH response to GHRH in Turner\'s syndrome
with normal body fat was still significantly lower than in NSC. It is
therefore concluded that somatotroph sensitivity to GHRH is decreased in
Turner\'s syndrome and that this may be due to the primary defects of
the somatotrophs rather than to the increased body fat. In addition, the
network of cholinergic-somatostatinergic systems seemed to be impaired
in these patients, while the activity of hypothalamic somatostatin
neurons was thought to be maintained.

435\. Hoeck, H.C., *et al.*, *Diagnosis of growth hormone (GH)
deficiency in adults with hypothalamic-pituitary disorders: comparison
of test results using pyridostigmine plus GH-releasing hormone (GHRH),
clonidine plus GHRH, and insulin-induced hypoglycemia as GH
secretagogues.* J Clin Endocrinol Metab, 2000. 85(4): p. 1467-72. The
insulin tolerance test (ITT) is widely accepted as the method of choice
to evaluate GH secretion capacity in adults with hypothalamic-pituitary
disorders. However, the test is not suitable in the elderly or in
patients with cardiovascular disease or seizure disorders. In recent
years alternatives to the ITT have been introduced. The purpose of the
present study was to investigate the diagnostic outcome with the ITT,
the pyridostigmine plus GHRH (PD + GHRH) test, the clonidine plus GHRH
(CLO+GHRH) test, and insulin-like growth factor I (IGF-I) in an
unselected group of patients with hypothalamic-pituitary disease. An
evaluation of the reproducibility of the different stimulation tests was
included in the study. Based on repeated testing with the various GH
stimulation tests in healthy adult males and females, the lower limits
of normality for the ITT, the PD+GHRH test, and the CLO+GHRH test were
3.92, 12.8, and 19.0, microg/L, respectively. A consecutive group of 26
unselected patients with hypothalamic-pituitary disorders, 13 males and
13 females (median age, 44 ys), were tested twice with all stimulation
tests, except that only 10 patients were tested once with the CLO+GHRH
test due to side-effects related to clonidine. The peak GH responses
between test 1 and test 2 correlated significantly in both the ITT and
the PD + GHRH test (P \< 0.02), and no significant difference was
observed in the median peak response to repeated testing. In addition,
no sex difference was observed. The coefficients of variation (CV) were
96% (ITT) and 45% (PD + GHRH), but in the majority of patients low
values were repeatedly low. The peak GH response was significantly
higher during the PD+GHRH test than during the ITT (P = 0.008). In the
10 patients tested with the PD+GHRH and CLO+GHRH tests there was no
significant difference in the peak GH response (P = 0.398). When the
test specific cut-off values were used, no significant difference in
diagnostic outcome was observed between the various tests (P \> 0.3). In
contrast, the diagnosis obtained with IGF-I differed significantly from
all GH stimulation tests (P \< 0.03). Twenty (77%) and 22 (85%) patients
were diagnosed to be GH deficient with the ITT and the PD+GHRH test,
respectively. Of the 14 patients with multiple pituitary failure (\>2
hormones affected), GH deficiency was present in more than 90%
regardless of the type of stimulation test used. The IGF-I levels were
only subnormal in 42% of the patients and did not correlate with the
peak GH responses in any of the stimulation tests (P \> 0.05). Except
for 1 patient all patients with subnormal IGF-I were GH deficient in all
stimulation tests. It is concluded that in patients with
hypothalamic-pituitary disease and a normal IGF-I level 2 stimulation
tests should be performed to establish a diagnosis of GH deficiency. In
patients with a subnormal IGF-I value a single GH stimulation test
should be sufficient to confirm the presence of GH deficiency.

436\. Kirk, J.M., *et al.*, *Pyridostigmine fails to increase either
spontaneous or GHRH-stimulated GH secretion during day or night in
growth hormone-insufficient children.* Clin Endocrinol (Oxf), 1991.
34(5): p. 407-11. OBJECTIVE The aim of the study was to investigate
whether pyridostigmine, a cholinesterase inhibitor which is thought to
act at the hypothalamus to inhibit somatostatin secretion, would augment
spontaneous or GHRH-stimulated serum GH levels in patients with
GH-insufficiency. DESIGN Oral pyridostigmine 60 mg or placebo was
administered at the start of a 9-h subcutaneous infusion of either GHRH
(1-29)NH2 10 micrograms/kg/h or saline control. Studies were performed
during the daytime (0900-1800 h) in five patients, and the night-time
(2100-0600 h) in a further five. PATIENTS Ten short, pre-pubertal
children (aged 6-11 years; eight boys) with growth hormone insufficiency
were studied. MEASURES Blood for serum GH was sampled every 20 min, and
analysed using the PULSAR program. RESULTS The subcutaneous infusion of
GHRH 10 micrograms/kg/h increased mean serum GH levels (+/- SEM): by day
17.7(+/- 6.8) vs placebo 2.2(+/- 0.4) mU/l (P less than 0.01), and by
night 26.9(+/- 3.3) vs 5.5(+/- 1.3) mU/l (P less than 0.05). There was a
significant rise in mean \'baseline\' GH concentration: by day 5.5(+/-
1.7) vs 1.0(+/- 0.0) mU/l (P less than 0.05); and night 8.2(+/- 2.7) vs
1.3(+/- 0.3) mU/l (P less than 0.05). Pyridostigmine failed to produce a
significant overall increase in either spontaneous or GHRH-stimulated GH
secretion by day or night, although there was a significant rise in mean
GH levels during the 3 h following pyridostigmine administration in the
morning: 4.4(+/- 1.1) vs 2.4(+/- 0.5) mU/l (P less than 0.001). GHRH or
pyridostigmine given singly or in combination had no significant effect
on the number of pulses. Side-effects attributable to pyridostigmine
occurred in seven children. CONCLUSIONS Pyridostigmine, either on its
own or as an adjuvant therapy in combination with GHRH, acts for only a
brief time and does not offer any potential benefit in the management of
children with short stature.

437\. Lamperti, E., *et al.*, *Growth hormone responses to
cholinergically active drugs in patients with dementia of the Alzheimer
type.* Alzheimer Dis Assoc Disord, 1992. 6(1): p. 44-52. Patients with
dementia of the Alzheimer type (DAT) reportedly have reduced
concentrations and function of some brain messengers, particularly
acetylcholine and somatostatin, not only in the cerebral cortex, but
also in subcortical structures, e.g., the hippocampus and the
hypothalamus. We wished to determine the responsive pattern of DAT
patients to neurohormonal and pharmacologic probes affecting growth
hormone (GH) release through an interaction with hypothalamic
cholinergic and somatostatinergic (SS) neurons. In 10 DAT patients,
pyridostigmine (120 mg orally, p.o.), an inhibitor of
acetylcholinesterase, induced an increase in GH levels similar to that
elicited by the drug in age-matched controls. In 9 DAT patients,
administration of GH-releasing hormone (GHRH, 1 microgram/kg body
weight, intravenously, i.v.) induced an increase in plasma GH not
different from that evidenced in control subjects. In DAT patients the
GHRH-induced GH increase was completely inhibited by pretreatment with
atropine (1 mg intramuscularly, i.m., 15 min before administration of
GHRH). These findings are considered to indicate that in DAT patients,
hypothalamic cholinergic and somatostatinergic neurons involved in
control of somatotropic function are preserved.

438\. Leal-Cerro, A., *et al.*, *Effect of enhancement of endogenous
cholinergic tone with pyridostigmine on growth hormone (GH) responses to
GH-releasing hormone in patients with Cushing\'s syndrome.* Clin
Endocrinol (Oxf), 1990. 33(2): p. 291-5. Growth hormone (GH) secretion
in patients with Cushing\'s syndrome is diminished to all the stimuli
tested so far but the precise mechanisms through which this occurs are
unknown. In order to investigate whether increased somatostatinergic
tone might be responsible for this alteration, we studied the effect of
pyridostigmine (120 mg p.o. at -60 min), which activates cholinergic
synapses and thus suppresses hypothalamic somatostatin release on GH
responses to GHRH (100 micrograms, i.v. at 0 min), in six patients with
Cushing\'s syndrome. We found that while pyridostigmine markedly
potentiated GH responses to GHRH, in all the normal subjects tested (n =
12), neither GHRH alone nor GHRH plus pyridostigmine elicited any
increase in GH secretion in any of the patients with Cushing\'s
syndrome. This suggests that chronic glucocorticoid excess induces
marked alterations in the hypothalamic control of GH secretion.

439\. Lee, E.J., *et al.*, *Growth hormone response to L-dopa and
pyridostigmine in women with polycystic ovarian syndrome.* Fertil
Steril, 1993. 60(1): p. 53-7. OBJECTIVE: To evaluate the GH secretion
and clarify the factors influencing the GH secretion in women with
polycystic ovarian syndrome (PCOS). DESIGN: Comparison of the GH
response to L-dopa with or without pyridostigmine (inhibitor of
acetylcholinesterase) pretreatment and insulin response to oral glucose
tolerance test in patients with PCOS and matched controls. SETTING:
Outpatients and healthy volunteers studied at a clinical research unit
of a university hospital. PATIENTS, PARTICIPANTS: Ten women with PCOS
and 9 controls with regular cycles were recruited. INTERVENTIONS: After
an overnight fast, each subject underwent a GH stimulation test with
L-dopa with or without pyridostigmine pretreatment. Plasma insulin and
glucose levels were measured after a 75-g glucose load. MAIN OUTCOME
MEASURES: Plasma GH, insulin-like growth factor I (IGF-I), insulin, and
nonesterified fatty acids. RESULTS: Growth hormone responses and GH area
under the response curve (AUC) to L-dopa were significantly lower in
PCOS than those in controls. Pyridostigmine enhanced the GH response to
L-dopa significantly in PCOS. Insulin responses and insulin AUC to oral
glucose load were significantly higher in PCOS than those in controls.
Plasma IGF-I levels of PCOS were significantly higher than controls.
Insulin AUC had a positive correlation with plasma IGF-I levels but an
inverse correlation with GH AUC in PCOS and controls. CONCLUSION: Our
result indicated that decreased GH secretion of PCOS may be associated
with a high somatostatin activity and a high plasma IGF-I level.

440\. Lee, E.J., *et al.*, *Reduced growth hormone response to L-dopa
and pyridostigmine in obesity.* Int J Obes Relat Metab Disord, 1994.
18(7): p. 465-8. The purpose of this study was to evaluate growth
hormone (GH) secretion and clarify the factors influencing GH secretion
in obesity. Nine obese subjects and eight controls were recruited. We
compared the GH response to L-dopa with or without pyridostigmine
pretreatment in obese and control subjects. Plasma glucose, insulin,
insulin-like growth factor I (IGF-I) and free fatty acid (FFA) were also
measured. Growth hormone responses and GH area under the response curve
(AUC) to L-dopa were significantly lower in obese subjects than those in
controls. Pyridostigmine significantly enhanced the GH response to
L-dopa in both obese and control subjects. However, enhanced GH
responses in obese subjects were attenuated biologically and lower than
those in controls with L-dopa only. Plasma levels of insulin insulin and
FFA were significantly higher in obese subjects than those in controls.
Body mass index had a positive correlation with the levels of insulin
and FFA. However, GH AUC had an inverse correlation with insulin and FFA
in obese subjects and controls. Stepwise multiple regression analysis
showed a highly significant effect of FFA on GH AUC, but no independent
influence of other factors on GH AUC. The reduced GH secretion found in
this study suggests an increase in somatostatinergic tone and a
diminished release of GHRH from the hypothalamus in obesity. However,
other factors including hyperinsulinemia and increased plasma FFA may
play an important additional role in the secretory dysfunction of GH in
obesity.

441\. Lee, E.J., *et al.*, *Acipimox potentiates growth hormone (GH)
response to GH-releasing hormone with or without pyridostigmine by
lowering serum free fatty acid in normal and obese subjects.* J Clin
Endocrinol Metab, 1995. 80(8): p. 2495-8. Obesity is associated with an
impairment of normal GH secretion and blunted responses to all stimuli.
Recent reports suggest that increased somatostatinergic activity is the
basis for the GH derangement of obesity. However, the basic mechanism of
this alteration is still being debated. The high plasma free fatty acid
(FFA) is frequently observed in obesity. FFA participates in the
regulation of pituitary GH secretion. To determine whether the
derangement of GH secretion in obesity is associated with high plasma
FFA levels, several tests with GHRH with or without pyridostigmine (PYR)
and acipimox (ACX), antilipolytic agents able to decrease FFA, were
undertaken in six obese and seven normal control subjects. In obese
subjects, the GH response (mean peak +/- SEM: 8.9 +/- 1.1 ug/L) to
GHRH-(1-29) (1 ug/kg, i.v.) was significantly blunted when compared with
the response in normal control subjects (25.7 +/- 1.8 ug/L; P \< 0.05).
After PYR (120 mg), the response to GHRH was enhanced in the obese
subjects (21.4 +/- 4.9 ug/L; P \< 0.05) and was similar to that of the
controls with GHRH only, but remained significantly reduced compared
with controls treated with PYR plus GHRH (43.2 +/- 6.0 ug/L; P \< 0.05).
Basal FFA levels were higher than those of normal controls (P \< 0.05).
ACX (500 mg) decreased FFA levels in both obese and normal subjects; the
lowest FFA levels of obese subjects at 15 min were similar to those of
normal controls. ACX also potentiated GHRH-stimulated GH response in
both obese and normal subjects. The GH responses potentiated by ACX in
obesity (22.7 +/- 5.5 ug/L) were similar to those of PYR plus GHRH in
obese subjects and GHRH in normal controls, but they were lower than
those of control treated with ACX plus GHRH (50.8 +/- 6.7 ug/L; P \<
0.05). After the combined pretreatment with ACX and PYR, GH responses in
obesity (44.1 +/- 6.0 ug/L) were significantly higher than those in GHRH
test, PYR plus GHRH, and ACX plus GHRH in obese subjects (P \< 0.05),
and they were similar to PYR plus GHRH or ACX plus GHRH in normal
controls. However their enhanced GH responses were reduced compared with
the control with ACX plus PYR plus GHRH (64.9 +/- 4.5 ug/L; P \< 0.05).
Our results are in agreement with the hypothalamic hypothesis: an
increase in somatostatinergic tone is responsible for the blunted GH
response to GHRH in obesity.(ABSTRACT TRUNCATED AT 250 WORDS).

442\. Loche, S., *et al.*, *Pyridostigmine counteracts the blunted
growth hormone response to growth hormone-releasing hormone of obese
children.* Acta Endocrinol (Copenh), 1989. 120(5): p. 624-8. We have
evaluated the effect of acute administration of pyridostigmine bromide,
a cholinesterase inhibitor, on the GHRH-induced GH rise in 11 obese
children and in 8 age-matched controls. The GH response to GHRH (hpGRF
1-40, 1 microgram/kg iv), evaluated both as maximum GH peak and as
integrated area under the curve, was significantly lower in the obese
children than in the controls. Pretreatment with pyridostigmine bromide
(60 mg orally 60 min before the GHRH injection) significantly increased
both baseline GH levels and the GH response to GHRH in all the obese
subjects, so that their mean baseline GH, peak GH levels and integrated
area under the curve after pyridostigmine bromide plus GHRH were similar
to those of the control children after GHRH. Also in control children
pyridostigmine bromide increased (though not significantly) baseline GH
levels. and caused a significant augmentation of the GH response to
GHRH. Mean peak GH levels and mean integrated area under the curve after
pyridostigmine bromide plus GHRH were significantly higher in the
controls than in the obese children given the same treatment. Mean
baseline Sm-C levels were significantly higher in the obese than in
control children. These data show that enhancement of cholinergic
neurotransmission, likely in the hypothalamus, counteracts the blunted
GH response to GHRH present in the obese children, and that in simple
obesity the potential of the pituitary to make a secretory response to a
direct GH secretagogue is preserved.

443\. Lucey, J.V., *et al.*, *Gender and age differences in the growth
hormone response to pyridostigmine.* Int Clin Psychopharmacol, 1991.
6(2): p. 105-9. Thirty healthy subjects 12 males and 18 females were
given the acetylcholinesterase inhibitor pyridostigmine (120 mg) orally.
The growth hormone (GH) response was measured as the maximum GH level
post-pyridostigmine relative to baseline. Twenty-six subjects increased
their GH level in response to pyridostigmine. Responses in females were
considerably greater than those in males and correlated closely with
serum oestradiol levels. Overall there was a significant negative
correlation between GH response and age.

444\. Lucey, J.V., *et al.*, *Elevated growth hormone responses to
pyridostigmine in obsessive-compulsive disorder: evidence of cholinergic
supersensitivity.* Am J Psychiatry, 1993. 150(6): p. 961-2. The growth
hormone response to the acetylcholinesterase inhibitor pyridostigmine
was measured in nine normothymic outpatients who met DSM-III-R criteria
for obsessive-compulsive disorder. The responses were significantly
elevated when compared to those found in a healthy comparison group (N =
9). The data suggest that cholinergic supersensitivity is present in
obsessive-compulsive disorder.

445\. Mancini, A., *et al.*, *Pre- and postprandial pyridostigmine and
oxiracetam effects on growth hormone secretion in anorexia nervosa.*
Psychoneuroendocrinology, 1996. 21(7): p. 621-9. Previous studies have
shown that food ingestion is not capable of inhibiting the GHRH-induced
GH release in anorexia nervosa, at variance with what is observed in
normal subjects. Moreover, a cholinergic alteration has been
hypothesized in this disorder. In a group of 24 anorectic patients in a
stabilized phase of the illness, we tested, before and after a standard
meal, the GH response to GHRH alone and after pre-treatment with
pyridostigmine, an inhibitor of acetylcholinesterase, and, on a
different day, with oxiracetam, which stimulates the central cholinergic
neurones. The GH response to GHRH was significantly increased by both
drugs in a fasting state. The postprandial response was not
significantly modified by pyridostigmine nor by oxiracetam. Neither of
these compounds was able to enhance the postprandial GH \'paradoxical\'
response to GHRH in anorectic patients. The lack of effect of both
groups postprandially also suggests a suppression of somatostatinergic
activity.

446\. Martina, V., *et al.*, *Repeated administration of growth
hormone-releasing hormone with or without previous administration of
pyridostigmine in insulin-dependent diabetes mellitus.* Horm Metab Res,
1997. 29(4): p. 180-3. In insulin dependent diabetes mellitus (IDDM)
either elevated growth hormone (GH) levels or abnormal responses to
specific as well as unspecific stimuli have been reported. As
hyperglycemia is known to blunt GH response to various stimuli, a normal
GH response to GHRH in presence of hyperglycemia should also be
considered inappropriate. To investigate the mechanism underlying this
inappropriate GH response, in 9 patients with IDDM, selected for normal
GH response to GHRH, we studied the GH response to two consecutive GHRH
boluses (1 microgram/kg), the second of which preceded 30 min before by
pyridostigmine (120 mg p.o.). Seven age matched normal volunteers were
evaluated as control group. Basal plasma glucose and serum GH levels
were significantly higher in patients with IDDM than in normal subjects
(184.4 +/- 9.6 vs 86.2 +/- 4.4 mg/dl, p \< 0.01 and 2.4 +/- 1.0 vs 1.0
+/- 0.4 microgram/l, p \< 0.01 respectively). Both in normal subjects
and in patients with IDDM the GH response to the second consecutive GHRH
administration was lower than that of the first GHRH bolus (delta AUC:
82.5 +/- 28.3 vs 401.1 +/- 131.2 micrograms/l/h, p \< 0.05 and 77.2 +/-
30.4 vs 336.8 +/- 60.0 p \< 0.02, respectively). Pyridostigmine was able
to restore the blunted GH responsiveness to the second GHRH
administration in both groups, but this response was found higher in
normal than in diabetic subjects (delta AUC: 1250.8 +/- 136.2 vs 527.5
+/- 147.6, p \< 0.01). Since the GH-releasing effect of PD is likely to
be mediated by the inhibition of hypothalamic somatostatin release, our
results suggest that there is also an impaired somatostatin tone in
hyperglycemic type 1 diabetic patients with normal GH response to GHRH.

447\. Massara, F., *et al.*, *Potentiation of cholinergic tone by
pyridostigmine bromide re-instates and potentiates the growth hormone
responsiveness to intermittent administration of growth
hormone-releasing factor in man.* Acta Endocrinol (Copenh), 1986.
113(1): p. 12-6. It is known that in normal subjects repeated
administration of the growth hormone-releasing factor (GRF) induces a
state of partial refractoriness of the somatotropes to GRF. Studies were
conducted to verify whether the cholinergic system plays a role in the
mechanism(s) underlying the reduced GH responsiveness to the
neuropeptide. In five healthy men, the GH response to three consecutive
injections of GRF (50 micrograms iv), administered at 2 h intervals, was
considerably blunted after the second and third GRF bolus.
Administration of the inhibitor of cholinesterase, pyridostigmine
bromide (120 mg orally) 30 min before the second GRF bolus, not only
restored but greatly potentiated the GH responsiveness to the second GRF
bolus. The GH response to the third GRF bolus was not apparently
influenced by pre-treatment with pyridostigmine. These data reinforce
the view that cholinergic neurotransmission plays an important role in
the control of GH secretion in human.

448\. Murialdo, G., *et al.*, *Effects of pyridostigmine,
corticotropin-releasing hormone and growth hormone-releasing hormone on
the pituitary-adrenal axis and on growth hormone secretion in dementia.*
Neuropsychobiology, 1993. 28(4): p. 177-83. Alterations of
neuroendocrinological indices determined by the impaired regulating
effects of cholinergic neurotransmission have been described in primary
dementia. In this study we have evaluated the effects of
acetylcholinesterase inhibition by pyridostigmine on growth hormone
(GH), adrenocorticotropic hormone (ACTH) and cortisol secretion and on
their responses to GH-releasing hormone (GHRH) and
corticotropin-releasing hormone (CRH) in 7 patients with primary
degenerative dementia and in 8 sex- and age-matched controls. Demented
subjects showed higher cortisol basal levels and lower ACTH levels than
controls. Pyridostigmine increased the GH response to GHRH in both
groups, the effect being significantly enhanced in patients. An increase
of ACTH and cortisol levels was found in both groups after
pyridostigmine and CRH administration. Pyridostigmine pretreatment
significantly increased the ACTH response to CRH in controls but not in
patients. The obtained data may indicate that a muscarinic receptor
upregulation and an impairment of somatostatinergic function are
operative in the regulation of GH secretion in dementia. An underlying
hyperactivity of the hypothalamic-pituitary-adrenal axis impairs the
responses of ACTH and cortisol to CRH in this disorder.

449\. O\'Keane, V. and T.G. Dinan, *Sex steroid priming effects on
growth hormone response to pyridostigmine throughout the menstrual
cycle.* J Clin Endocrinol Metab, 1992. 75(1): p. 11-4. To explore the
effect of estradiol and progesterone on the GH response to the indirect
cholinergic agonist pyridostigmine nine healthy women were challenged
with both active drug and placebo at three time points in two
consecutive menstrual cycles: a total of six neuroendocrine tests. A
randomized, double-blind, counterbalanced design was used. Subjects were
tested in the early follicular, mid-cycle, and luteal phases of the
cycle. A cannula was inserted in a forearm vein after an overnight fast
and baseline GH, estradiol, and progesterone samples were drawn. After
120 mg oral pyridostigmine or placebo tablets further blood samples for
GH analysis were drawn at intervals over 3 h. When expressed as maximum
change from baseline (delta GH) mean GH responses to pyridostigmine
increased incrementally from early (8.4 +/- 2.7 micrograms/L) through
mid (18 +/- 1.3 micrograms/L) to late (22.2 +/- 1.9 micrograms/L) cycle.
This represents a significant effect of cycle phase on the GH response
to pyridostigmine (P less than 0.001, as assessed by analysis of
variance). Responses to placebo did not vary. Plasma estradiol values
were significantly correlated with GH responsivity to active drug
throughout the cycle (P less than 0.02). Multiple regression analysis
also revealed a significant positive correlation between progesterone
levels and GH response to pyridostigmine (P less than 0.02). Estrogens
augment GH responses to other challenges but a priming effect of
progesterone on GH responsivity has not previously been demonstrated.
Various mechanisms are discussed including a possible sex steroid
priming effect on acetylcholine neurotransmission.

450\. O\'Keane, V., *et al.*, *Pyridostigmine-induced growth hormone
responses in healthy and depressed subjects: evidence for cholinergic
supersensitivity in depression.* Psychol Med, 1992. 22(1): p. 55-60.
Theorists have extrapolated the cholinergic supersensitivity theory of
affective disorder from a convincing and broad spectrum of clinical
observation and research. This hypothesis is tested using a
neuroendocrine probe approach with the challenge drug pyridostigmine, an
indirect cholinergic agent thought to release growth hormone (GH) by
decreasing inhibitory somatostatin tone. The consequent increments in
plasma GH were considered to reflect central acetylcholine responsivity.
Fifty-four volunteers were tested: 27 DSM-III-R major depressives (18
women and 9 men) and 27 age- and sex-matched healthy controls. Subjects
were cannulated at 9.00 h following an overnight fast and two baseline
samples were taken at 15 min intervals. Pyridostigmine 120 mg was
administered orally and thereafter samples were taken at the time points
+60, +90, +120 and +180 min. GH responses were significantly greater in
depressives than controls and this effect was more marked for men than
women. These results support the proposal that muscarinic upregulation
and/or supersensitivity is associated with depression.

451\. O\'Keane, V., K. Abel, and R.M. Murray, *Growth hormone responses
to pyridostigmine in schizophrenia: evidence for cholinergic
dysfunction.* Biol Psychiatry, 1994. 36(9): p. 582-8. The hypothesis
that increased central cholinergic neurotransmitter function may be
present in schizophrenic illness and may underlie negative symptoms was
tested using a neuroendocrine challenge approach. The cholinergic
challenge used was the anticholinesterase pyridostigmine, thought to
cause the release of growth hormone (GH) from the anterior pituitary by
diminishing inhibitory somatostatin tone. Eleven patients, six
neuroleptic-naive and five neuroleptic-free, satisfying DSM-III-R
criteria for schizophrenia and 11 matched controls took part. Subjects
received pyridostigmine (120 mg orally) and blood was sampled at 0, 60,
90, 120, and 180 min for GH estimation. Peak GH responses were
significantly increased in the schizophrenic group compared to controls.
There was no relationship between individual peak GH values and negative
symptom ratings (Scale for the Assessment of Negative Symptoms). Neither
could a relationship be established between other aspects of
psychopathology or dyskinesias and GH responses. An increased
pyridostigmine/GH response is also found in affective disorders and
could be related to nonspecific symptoms common to all these diagnostic
groups. This study suggests that schizophrenia may be associated with
increased cholinergic neurotransmitter function but the relationship
between this cholinergic dysfunction and schizophrenia may involve
psychopathology not specific to schizophrenia.

452\. Penalva, A., *et al.*, *Activation of cholinergic
neurotransmission by pyridostigmine reverses the inhibitory effect of
hyperglycemia on growth hormone (GH) releasing hormone-induced GH
secretion in man: does acute hyperglycemia act through hypothalamic
release of somatostatin?* Neuroendocrinology, 1989. 49(5): p. 551-4.
Acute hyperglycemia blocks growth hormone (GH) secretion in response to
provocative stimuli including growth hormone releasing hormone (GHRH)
administration. However, the precise mechanism of glucose action is
unknown. To determine if enhanced somatostatinergic stimulation accounts
for the decreased GH secretion, we studied the effect of enhanced
cholinergic tone by pyridostigmine on the hyperglycemia blockade of GH
release in 7 normal subjects. Pyridostigmine, an acetylcholinesterase
inhibitor, has been postulated as an inhibitor of somatostatin release.
Each subject underwent 4 tests with GHRH injection (100 micrograms i.v.
at 0 min). In the first (control) test, placebo was administered before
GHRH. In the second test, 100 g of glucose was administered p.o. 45 min
before GHRH. In the third test, pyridostigmine, 120 mg p.o., was
administered 60 min before GHRH, and in the fourth test, pyridostigmine,
glucose and GHRH were administered at -60, -45 and 0 min, respectively.
GHRH-induced GH secretion of 25.8 +/- 4.5 ng/ml was significantly
reduced by previous glucose administration (12.1 +/- 4.5 ng/ml) and
significantly potentiated by previous pyridostigmine pretreatment (56.5
+/- 16.8 ng/ml). In the fourth test (pyridostigmine plus glucose plus
GHRH) the GH peak of 42.4 +/- 9.2 ng/ml was significantly higher than
after GHRH alone and not different to the pyridostigmine-GHRH test. In
conclusion, central cholinergic activation by pyridostigmine reversed
the hyperglycemic blockade of GHRH-induced GH secretion. In addition,
hyperglycemia was unable to reduce the potentiating effect of
pyridostigmine on GH secretion elicited by GHRH. Based on the reported
actions of pyridostigmine, acute hyperglycemia might act over GH release
by inducing hypothalamic somatostatin release.

453\. Penalva, A., *et al.*, *Effect of enhancement of endogenous
cholinergic tone with pyridostigmine on the dose-response relationships
of growth hormone (GH)-releasing hormone-induced GH secretion in normal
subjects.* J Clin Endocrinol Metab, 1990. 70(2): p. 324-7. It is well
known that GH responses to GH-releasing hormone (GHRH) show marked
interindividual variations in normal subjects, which have been
attributed to a variable somatostatinergic tone. Recently, it has been
shown that enhancement of cholinergic tone with the acetylcholinesterase
inhibitor pyridostigmine (PD), which presumably acts by inhibiting
somatostatin release, stimulates basal GH secretion and GH responses to
a maximal dose of GHRH. In this study we have investigated the effects
of PD on the dose-response relationships of GHRH-induced GH secretion in
normal subjects. Our data showed that PD (120 mg, orally, at-60 min)
induced a clear-cut increase in basal GH levels, significantly different
from that after saline treatment, at 15, 30, 45, 60, 90, and 120 min.
Moreover, PD administration markedly potentiated GH responses to GHRH at
doses of 500, 100, 25, 10, and 3 micrograms/subject, as assessed by
either area under the curve or maximal peak GH levels. In fact, GH
responses to pyridostigmine plus 3 micrograms GHRH were similar to those
to the administration of 500 and 100 micrograms GHRH alone. Our findings
of marked increases in GH response to GHRH after pyridostigmine
administration show that with enhancement of cholinergic tone, the dose
of GHRH needed to induce a similar increase in GH is reduced 30 times.

454\. Penalva, A., *et al.*, *Effect of growth hormone (GH)-releasing
hormone (GHRH), atropine, pyridostigmine, or hypoglycemia on
GHRP-6-induced GH secretion in man.* J Clin Endocrinol Metab, 1993.
76(1): p. 168-71. His-DTrp-Ala-Trp-DPhe-Lys-NH2 (GHRP-6) is a synthetic
compound that releases GH in a dose-related and specific manner in
several species, including man. To further characterize the effects and
mechanism of action of GHRP-6 on GH secretion, we assessed in normal man
plasma GH responses to that hexapeptide 1) alone and in combination with
exogenous GH-releasing hormone (GHRH) administration, 2) in a state of
high endogenous somatostatinergic tone after atropine administration,
and 3) in a state of low endogenous somatostatinergic tone induced by
the cholinergic receptor agonist drug pyridostigmine or after
insulin-induced hypoglycemia. We found a similar increase in plasma GH
levels after the administration of either GHRP-6 (1 microgram/kg) or
GHRH (1 microgram/kg); the areas under the curve (AUC) were (mean +/-
SEM) 973 +/- 181 and 821 +/- 139, respectively. After combined GHRP-6
and GHRH administration, GH responses were considerably greater than
those after either compound alone (4412 +/- 842; P \< 0.01).
Administration of the cholinergic receptor antagonist atropine (1 mg,
im) completely prevented the GH responses to GHRP-6 (area under the
curve, 103 +/- 14 vs. 815 +/- 156, respectively). On the other hand,
pyridostigmine, a cholinergic agonist, slightly increased GH responses
to GHRP-6 (P \< 0.01 when comparing the AUC after pyridostigmine
administration of 1571 +/- 151 and the AUC after administration of
GHRP-6 alone of 815 +/- 156). Finally, combined GHRP-6 and insulin
administration induced a much greater increase in plasma GH levels (AUC,
4047 +/- 327) than insulin alone (1747 +/- 229; P \< 0.05) or GHRP-6
alone (1248 +/- 376; P \< 0.05). Our results lend support to the view
that GHRP-6-induced GH secretion is exerted through a non-GHRH-dependent
mechanism. Furthermore, the fact that enhancement of somatostatinergic
tone with atropine completely prevented the GH responses to GHRP-6,
while pyridostigmine and insulin-induced hypoglycemia, which increased
plasma GH levels by inhibiting hypothalamic somatostatin release,
increased the same response suggest that although GHRP-6-induced GH
secretion is dependent on the endogenous somatostatinergic tone, the
stimulatory effect of GHRP-6 on plasma GH levels is not mediated by a
change in hypothalamic somatostatinergic tone.

455\. Procopio, M., *et al.*, *Effect of arginine and pyridostigmine on
the GHRH-induced GH rise in obesity and Cushing\'s syndrome.* Int J Obes
Relat Metab Disord, 1995. 19(2): p. 108-12. OBJECTIVES: The aim of this
work was to clarify the mechanisms underlying growth hormone (GH)
hyposecretion in Cushing\'s syndrome (CS) and in obesity. We studied the
GH response to GH-releasing hormone (GHRH) alone and combined with
arginine or pyridostigmine, two substances likely to inhibit
hypothalamic somatostatin release. DESIGN: Three tests with GHRH alone
(1 microgram/kg i.v. at 0 min) and combined with arginine (ARG, 0.5 g/kg
infused over 30 min) or pyridostigmine (PD, 120 mg orally at -60 min)
were performed 3 days apart and in random order in eight women with CS
(five with ACTH-dependent and three with ACTH-independent
hypercortisolism, age 18-56, BMI 26.1 +/- 1.5 Kg/m2) and 11 with OB (age
17-54, BMI 42.9 +/- 2.2 Kg/m2). Eleven normal women (age 23-50, BMI 21.9
+/- 0.3 Kg/m2) were studied as controls (C). MEASUREMENTS: Serum GH and
IGF-I levels were measured by radioimmunoassay. The GH secretory
responses were expressed either as absolute values (micrograms/L) or as
areas under the curve (AUC, micrograms/L/h) calculated by trapezoidal
integration. IGF-I concentrations were expressed as absolute values
(micrograms/L) with reference to a pure recombinant IGF-I preparation.
RESULTS: Basal GH levels in CS were similar to those registered in OB
(mean +/- s.e.m. 0.7 +/- 0.1 vs 0.9 +/- 0.2 microgram/L) and lower than
in C (3.4 +/- 0.5 microgram/L, P \< 0.00001). On the other hand, IGF-I
levels were similar in all groups. The GHRH-induced GH rise in CS was
lower, though not significantly, to that observed in OB (AUC: 65.6 +/-
13.2 vs 192.5 +/- 61.7 microgram/L/h) and both GH responses were
significantly lower than that of C (1029.9 +/- 98.0 micrograms/L/h, P \<
0.00001). ARG enhanced the GHRH-induced GH release in CS (331.9 +/- 51.9
micrograms/L/h vs GHRH alone, P \< 0.0001), OB (852.4 +/- 162.1
micrograms/L/h, P \< 0.0001) and C (3362.6 +/- 386.0 micrograms/L/h, P
\< 0.0002). However, the GH response to GHRH plus ARG in CS was lower (P
\< 0.002) than that in OB which, in turn, was lower than that in C (P \<
0.00001). Pyridostigmine significantly enhanced the GHRH-induced GH rise
in C (2808.5 +/- 221.2 micrograms/L/h, P \< 0.00001) and, to a lesser
extent, in OB (627.3 +/- 84.7 micrograms/L/h, P \< 0.0002) but not in CS
(102.9 +/- 25.0 micrograms/L/h). CONCLUSIONS: Our results indicate that
the GH releasable pool is reduced in obesity and, to an even greater
extent, in Cushing\'s syndrome. The inability of pyridostigmine and
arginine to restore a normal GH response to GHRH in these conditions
makes the existence of a hypothalamic somatostatinergic hyperactivity
unlikely.

456\. Procopio, M., *et al.*, *GH response to GHRH combined with
pyridostigmine or arginine in different conditions of low somatotrope
secretion in adulthood: obesity and Cushing\'s syndrome in comparison
with hypopituitarism.* Panminerva Med, 1998. 40(1): p. 13-7. BACKGROUND:
Diagnosing GH deficiency in adults is difficult due to the age-related
variations of GH/IGF-I axis and the influence of nutrition. Nowadays, GH
replacement is allowed for patients with GH peak to provocative stimuli
\< 3 micrograms/L. Somatotrope insufficiency is present in
hypopituitarism but also in obesity and hypercortisolism. However, to
evaluate GH insufficiency in adults is difficult due to variations of GH
and IGF-I levels as function of age and nutrition status. METHODS: We
aimed to verify the GH response to GHRH (1 microgram/kg i.v.) combined
with pyridostigmine (PD, 120 mg p.o.) or arginine (ARG, 0.5 g/kg i.v.),
in 26 hypopituitaric patients (GHD), in 11 obese women (OB), in 8 women
with Cushing\'s syndrome (CS), and in 72 control subjects (NS). RESULTS:
IGF-l levels in GHD were lower than those in OB (p \< 0.01) and in CS (p
\< 0.01) which, in turn, were lower to those in NS (p \< 0.02). In NS,
the GH peak responses to GHRH + PD and GHRH + ARG were similar and the
minimum normal GH peak was 16.5 micrograms/L. GHD had GH responses
similar, lower than those in NS (p \< 0.01) and always below the normal
limit. However, only 12/20 and 8/14 had peaks \< 3 micrograms/L;
conventionally, below this limit severe GH deficiency is shown and rhGH
replacement is allowed. In OB, the GH responses to GHRH + PD and GHRH +
ARG were similar, lower (p \< 0.01) and higher (p \< 0.01) than those in
NS and GHD, respectively. Six out of 11 OB had GH peaks below the normal
limits but nobody \< 3 micrograms/L. In CS the GH response to GHRH + PD
was lower than that to GHRH + ARG (p \< 0.01); both these responses were
lower than those in NS (p \< 0.01) and even in OB (p \< 0.01) but higher
than those in GHD (p \< 0.01). All and 7/8 CS had GH peaks lower than
normal limits after PD + GHRH and ARG + GHRH, respectively while 6/8
showed GH peak \< 3 micrograms/L after PD + GHRH but only 1 after ARG +
GHRH. CONCLUSIONS: Present data demonstrate that the maximal somatotrope
secretory capacity is reduced in OB and even more in CS. From a
diagnostic point of view, PD + GHRH and ARG + GHRH tests distinguish OB
from severe GHD. As hypercortisolism impairs the activity of
cholinesterase inhibitors, only ARG + GHRH, but not PD + GHRH is a
reliable test to explore the maximal somatotrope secretory capacity in
CS. Notably, even with the ARG + GHRH test, in CS the maximal
somatotrope secretory capacity is sometimes so reduced as to overlap
with that of severe GHD.

457\. Procopio, M., *et al.*, *GH response to GHRH combined with
pyridostigmine or arginine in different conditions of low somatotrope
secretion in adulthood: obesity and Cushing\'s syndrome in comparison
with hypopituitarism.* Minerva Endocrinol, 1999. 24(3-4): p. 107-11.
BACKGROUND: Diagnosing GH deficiency in adults is difficult due to the
age-related variations of GH/IGF-I axis and the influence of nutrition.
Nowadays, GH replacement is allowed for patients with GH peak to
provocative stimuli \< 3 micrograms/L. Somatotrope insufficiency is
present in hypopituitarism but also in obesity and hypercortisolism.
However, to evaluate GH insufficiency in adults is difficult due to
variations of GH and IGF-I levels as function of age and nutrition
status. METHODS: We aimed to verify the GH response to GHRH (1 mg/kg
i.v.) combined with pyridostigmine (PD, 120 mg p.o.) or arginine (ARG,
0.5 g/kg i.v.), in 26 hypopituitaric patients (GHD), in 11 obese women
(OB), in 8 women with Cushing\'s syndrome (CS), and in 72 control
subjects (NS). RESULTS: IGF-I levels in GHD were lower than those in OB
(p \< 0.01) and in CS (p \< 0.01) which, in turn, were lower to those in
NS (p \< 0.02). In NS, the GH peak responses to GHRH + PD and GHRH + ARG
were similar and the minimum normal GH peak was 16.5 mg/L. GHD had GH
responses similar, lower than those in NS (p \< 0.01) and always below
the normal limit. However, only 12/20 and 8/14 had peaks \< 3
micrograms/L; conventionally, below this limit severe GH deficiency is
shown and rhGH replacement is allowed. In OB, the GH responses to GHRH +
PD and GHRH + ARG were similar, lower (p \< 0.01) and higher (p \< 0.01)
than those in NS and GHD, respectively. Six out of 11 OB had GH peaks
below the normal limits but nobody \< 3 micrograms/L. In CS, the GH
response to GHRH + PD was lower than that to GHRH + ARG (p \< 0.01);
both these responses were lower than those in NS (p \< 0.01) and even in
OB (p \< 0.01) but higher than those in GHD (p \< 0.01). All and 7/8 CS
had GH peaks lower than normal limits after PD + GHRH and ARG + GHRH,
respectively while 6/8 showed GH peak \< 3 micrograms/L after PD + GHRH
but only 1 after ARG + GHRH. CONCLUSIONS: Present data demonstrate that
the maximal somatotrope secretory capacity is reduced in OB and even
more in CS. From a diagnostic point of view, PD + GHRH and ARG + GHRH
tests distinguish OB from severe GHD. As hypercortisolism impairs the
activity of cholinesterase inhibitors, only ARG + GHRH, but not PD +
GHRH is a reliable test to explore the maximal somatotrope secretory
capacity in CS. Notably, even with the ARG + GHRH test, in CS the
maximal somatotrope secretory capacity is sometimes so reduced as to
overlap with that of severe GHD.

458\. Rico, M., *et al.*, *Effect of growth hormone-releasing peptide
1-6 on GH secretion-stimulated by GHRH and pyridostigmine in lambs.* J
Physiol Biochem, 1998. 54(2): p. 67-76. The GHRP-6 seems to act at a
pituitary site, activating different intracellular messenger pathways
from those utilized by GHRH, and at the hypothalamic level where
receptors for GHRP-6 have been demonstrated. This study examines the
effect of GHRP-6 on GH secretion in vitro and in vivo. Lamb
adenohypophysial cell cultures were subjected to a challenge with 1) 10
nM GHRH-1-29; 2) 1 microM GHRP-6; and 3) 10 nM GHRH plus 1 microM
GHRP-6. Both peptides released GH, GHRP-6 being less potent than GHRH,
and the GH response to GHRH and GHRP-6 not being synergistic, without
statistically significant differences between GHRH+GHRP-6 and GHRH
alone. In in vivo studies, six lambs received 15 microg/kg GHRH (1-29)
or 15 microg/kg GHRH plus 10 microg/kg GHRP-6 and six other lambs
received 100 microg/kg GHRP-6 or 3 mg/kg pyridostigmine plus 100
microg/kg GHRP-6. The results have shown that the combination of GHRH
plus GHRP-6, at low doses, causes higher GH peak (p \< 0.05) and higher
GH area under curve (p \< 0.05) with respect to administration of GHRH
alone. The administration of GHRP-6 plus pyridostigmine produced in a
stronger GH response to GHRP-6 (100 microg/kg) in the amplitude of the
GH peak (p \< 0.001) and in the area under the GH response curve (p \<
0.001). The complementary interactions of GHRP-6 with GHRH or
pyridostigmine in releasing GH seem to indicate independent actions of
these compounds. These results suggest that GHRP-6 potentiates the GH
secretion stimulated by GHRH at the hypothalamic level, in these
animals.

459\. Ross, R.J., *et al.*, *GH feedback occurs through modulation of
hypothalamic somatostatin under cholinergic control: studies with
pyridostigmine and GHRH.* Clin Endocrinol (Oxf), 1987. 27(6): p. 727-33.
We have studied the effect of increased cholinergic tone on the GH
response to growth hormone-releasing hormone (GHRH) and on GH feedback,
using pyridostigmine, an acetylcholinesterase inhibitor. In six healthy
male adult volunteers 120 mg oral pyridostigmine increased basal GH
secretion compared to placebo and augmented the GH response to 100
micrograms i.v. GHRH (1-29) NH2; the effect was more than the additive
effect of pyridostigmine and GHRH when each was given alone.
Pretreatment with 2 IU methionyl-hGH given i.v. abolished the serum GH
response to GHRH given 3 h later, demonstrating a negative feedback loop
of GH on the response to GHRH; this inhibited response to GHRH was
restored in subjects given pyridostigmine as well as methionyl-hGH. The
data demonstrate that enhanced cholinergic tone releases GH, augments
the serum GH response to GHRH and unblocks the negative feedback effect
of methionyl-hGH pretreatment on the GH response to GHRH. These results
suggest that GH negative feedback effects on its own secretion occur
predominantly through increased hypothalamic somatostatin secretion;
this somatostatin secretion is under inhibitory cholinergic control.

460\. Ross, R.J., *et al.*, *Growth hormone response to overnight growth
hormone-releasing hormone infusion and oral pyridostigmine in children
with short stature.* Acta Paediatr Scand Suppl, 1989. 349: p. 114-6;
discussion 123-4. The development of a long-acting or depot preparation
of growth hormone-releasing hormone (GHRH) may have many advantages over
conventional treatment (with GH) of GH-deficient children.
Pyridostigmine, an acetylcholinesterase inhibitor, has been shown to
augment basal GH secretion and the GH response to GHRH in short
children. It may thus provide adjuvant therapy to depot GHRH. The GH
response to a nocturnal subcutaneous infusion of GHRH (1-29)NH2 in doses
of 5 and 10 micrograms/kg/hour was investigated in five short, slowly
growing children. The effect of oral pyridostigmine 60 mg on nocturnal
GH secretion and the GH response to a nocturnal infusion was also
examined. The subcutaneous infusion of GHRH augmented pulsatile GH
release in all five children. There was a dose-related response to
subcutaneous GHRH for the GH area under the curve and mean GH pulse
amplitude, but no change in the number of pulses. There was a
significant rise in the mean baseline GH concentration during the GHRH
infusion compared with placebo. Pyridostigmine had no effect on either
basal or stimulated GH secretion.

461\. Thakore, J.H., I. Coffey, and T.G. Dinan, *Time dependency of
pyridostigmine-induced growth hormone response.* J Basic Clin Physiol
Pharmacol, 1994. 5(2): p. 117-23. Growth hormone (GH) plasma levels
reflect a balance between stimulation via GH-releasing hormone (GHRH)
and inhibition by somatostatin (SS). Steroids influence GH secretion by
modulating SS tone. There is a correlation between the diurnal secretion
of GH and cortisol (CORT). Pyridostigmine, the acetylcholinesterase
inhibitor, increases cholinergic tone, inhibits SS release and increases
the release of GH. We investigated the influence of CORT on
pyridostigmine-induced GH responses by testing subjects at 9.00 and
14.00 h. Basal (mean +/- SEM) CORT levels at 9.00 and 14.00 h were 251.5
+/- 18.4 nmol/l and 142.7 +/- 6.7 nmol/l, respectively.
Pyridostigmine-induced GH responses were greater at 9.00 h than at 14.00
h (8.7 +/- 1.5 mU/l; 3.0 +/- 1.0 mU/l, respectively, \[ p \< 0.001\]). A
positive correlation between CORT and delta GH values was demonstrated
(p \< 0.0004).

462\. Thakore, J.H. and T.G. Dinan, *Loss of the diurnal variation of
pyridostigmine-induced growth hormone responses in depression: the
effect of cortisol.* Int Clin Psychopharmacol, 1995. 10(2): p. 107-10.
Growth hormone (GH) plasma concentrations reflect a balance between
stimulation via GH-releasing hormone and inhibition by somatostatin.
Cholinergic agonists enhance GH release by inhibiting somatostatin
secretion and in health, stimulated GH release undergoes diurnal
variation. We investigated the influence of cortisol on
pyridostigmine-induced GH responses by testing six patients with
DSM-III-R major depression at 09.00 and 14.00 h. There were no
differences in GH responses to pyridostigmine between 09.00 and 14.00 h
despite a preservation of the circadian variation of cortisol levels. If
cortisol plays an important role in regulating cholinergic activity one
would expect the diurnal variation of pyridostigmine-induced GH release
to be preserved. As it is not, a reasonable assumption to make is that
the muscarinic supersensitivity observed in depression may be
independent of the prevailing steroid milieu.

463\. Trainer, P.J., *et al.*, *Pyridostigmine partially reverses
dexamethasone-induced inhibition of the growth hormone response to
growth hormone-releasing hormone.* J Endocrinol, 1992. 134(3): p. 513-7.
The GH response to insulin-induced hypoglycaemia and growth
hormone-releasing hormone (GHRH) has been shown to be impaired in
subjects with Cushing\'s syndrome and in healthy volunteers given oral
glucocorticoids. Pyridostigmine is an anticholinesterase that stimulates
GH secretion, probably by inhibition of hypothalamic somatostatin
secretion. This work was designed to study the site of action of
glucocorticoids in inhibiting the secretion of GH. Eight healthy male
volunteers were studied on three occasions in random order. They took 2
mg oral dexamethasone or placebo at precisely 6-hourly intervals for 48
h before receiving 120 mg oral pyridostigmine or placebo, followed 60
min later by GHRH (100 micrograms) i.v. Samples for measuring GH were
obtained at 15 min intervals for 2 h. The \'area under the curve\' (AUC)
for each of the treatments was significantly different:
dexamethasone-pyridostigmine-GHRH (mean +/- S.E.M., 1938 +/- 631 mU/min
per l), dexamethasone-placebo-GHRH (634 +/- 211) and
placebo-placebo-GHRH (4267 +/- 1183) (P \< 0.02, Wilcoxon test). In
conclusion, dexamethasone given for 48 h significantly inhibited the AUC
for GH following treatment with GHRH. However, pretreatment with
pyridostigmine significantly reversed the inhibition although this was
still partial. Our data suggested that this short-term suppressive
effect of dexamethasone was independent of GHRH, and most probably
relates to stimulation of the release of somatostatin.

464\. Trojan, D.A., *et al.*, *A multicenter, randomized, double-blinded
trial of pyridostigmine in postpolio syndrome.* Neurology, 1999. 53(6):
p. 1225-33. BACKGROUND: Postpoliomyelitis syndrome (PPS) is likely due
to degeneration and dysfunction of terminal axons of enlarged postpolio
motor units. Age-related decline in growth hormone and insulin-like
growth factor (IGF-I) may be a contributing factor. Neuromuscular
junction abnormalities and decreased IGF-I levels may respond to the
anticholinesterase pyridostigmine, with consequent improvement in
strength, fatigue, and quality of life. OBJECTIVES: To determine the
effect of pyridostigmine in PPS on health-related quality of life,
isometric muscle strength, fatigue, and serum IGF-I levels; and to
assess the safety of pyridostigmine in PPS. METHODS: The study was a
multicenter, randomized, double-blinded, placebo-controlled trial of a
6-month course of pyridostigmine 60 mg three times per day in 126 PPS
patients. The primary data analysis compared mean changes of outcomes
between treatment and control groups at 6 months using an intention to
treat approach. Secondary analyses included a comparison of outcomes at
6 and 10 weeks, and in compliant patients. RESULTS: The study showed no
significant differences in pyridostigmine and placebo-treated patients
with regard to changes in quality of life, isometric strength, fatigue,
and IGF-I serum levels at 6 months in the primary analysis and in
compliant patients. There were no differences in outcomes at 6 and 10
weeks between groups. However, very weak muscles (1 to 25% predicted
normal at baseline) were somewhat stronger (p = 0.10, 95% CI of
difference -9.5 to 73.3%), and in compliant patients IGF-I was somewhat
increased (p = 0.15, 95% CI of difference -6.4 to 44.8 ng/mL) at 6
months with the medication. Pyridostigmine was generally well tolerated.
CONCLUSIONS: This study showed no significant differences between
pyridostigmine and placebo-treated PPS patients on measures of quality
of life, isometric strength, fatigue, and serum IGF-I.

465\. Valcavi, R., *et al.*, *Effect of pyridostigmine and pirenzepine
on GH responses to GHRH in hyperthyroid patients.* Clin Endocrinol
(Oxf), 1991. 35(2): p. 141-4. OBJECTIVE: We wished to investigate
whether thyrotoxicosis can influence the cholinergic modulation of GH
secretion. DESIGN: Pyridostigmine was given orally, then GHRH injected
i.v., and levels were measured. In a separate study, pirenzepine was
injected i.v., then GHRH, and growth hormone levels were measured.
PATIENTS: Thyrotoxic patients were compared with normal subjects.
MEASUREMENTS: GH was measured from -30 to +120 minutes at intervals of
15 minutes. RESULTS: Pyridostigmine markedly increased GH responses to
GHRH in normal subjects, but not in thyrotoxic patients. Pirenzepine
abolished the GH response to GHRH in thyrotoxic patients. CONCLUSIONS:
GH responses to GHRH in hyperthyroid patients were suppressed by
cholinergic muscarinic receptor blockade with pirenzepine. Activation of
cholinergic pathways with pyridostigmine did not increase GH responses
to GHRH in these patients. This may be a consequence of increased
hypothalamic cholinergic function or reduced hypothalamic GHRH activity
in hyperthyroidism. Our findings demonstrate a further mechanism by
means of which thyroid status may affect the secretory activity of the
somatotroph.

466\. Valcavi, R., *et al.*, *The late growth hormone rise induced by
oral glucose is enhanced by cholinergic stimulation with pyridostigmine
in normal subjects.* Clin Endocrinol (Oxf), 1992. 37(4): p. 360-4.
OBJECTIVE: We have investigated the late GH rise occurring 3-5 hours
after oral glucose administration. We have assessed the effect of
endogenous cholinergic enhancement with pyridostigmine on the delayed GH
rise following oral glucose loading in normal subjects. DESIGN: Placebo
or 75 g oral glucose was given to the normal subjects 3 hours before 120
mg oral pyridostigmine or placebo. Four tests were carried out at
random. (0 min) + placebo (180 min); test 2: glucose (0 min) + placebo
(180 min); test 3: placebo (0 min) + pyridostigmine (180 min); test 4:
glucose (0 min) + pyridostigmine (180 min). SUBJECTS: We studied eight
normal subjects (four male and four female), ages 19-29 years, body mass
indices 18-22 kg/m2. MEASUREMENTS: Plasma glucose and serum GH
concentrations were measured for 6 hours after oral glucose or placebo
administration. RESULTS: Pyridostigmine treatment significantly enhanced
the GH releasing effect of prior (3 h) oral glucose. Late GH peak
obtained by oral glucose loading rose from (mean +/- SEM) 17.4 +/- 4.6
to 37.2 +/- 9.0 mU/l (P \< 0.05) after pyridostigmine, while GH peak
following placebo plus pyridostigmine was 12.4 +/- 2.0 mU/l (P \< 0.05
vs glucose plus pyridostigmine). The analysis of GH area under curves
(AUCs) in the second phase of the tests (180-360 min) confirmed that
glucose plus pyridostigmine released a greater amount of GH (4128 +/-
764 mU/l/3h) than glucose (1694 +/- 494 mU/l/3h, P \< 0.001) or
pyridostigmine alone (1292 +/- 150 mU/I/3h, P \< 0.001). CONCLUSIONS:
Pyridostigmine, an indirect cholinergic drug likely to inhibit
somatostatin secretion from the hypothalamus, enhanced the late GH
releasing activity of oral glucose. There is evidence that glucose
suppresses plasma GH initially by increasing hypothalamic somatostatin
release. This would result in an increase in the pituitary stores of GH.
We propose that the delayed GH rise after oral glucose occurs when there
is a fall in hypothalamic somatostatinergic tone; this is further
reduced by the administration of pyridostigmine. At this time the
pituitary stores of GH are released as a consequence of resumption of
hypothalamic GHRH activity. This leads to the late GH rise.

467\. Valcavi, R., *et al.*, *Evidence against depletion of the growth
hormone (GH)-releasable pool in human primary hypothyroidism: studies
with GH-releasing hormone, pyridostigmine, and arginine.* J Clin
Endocrinol Metab, 1993. 77(3): p. 616-20. We investigated whether the
impaired GH secretion of hypothyroid patients could be due to an
increase in hypothalamic somatostatinergic tone. Twenty-four patients
with primary hypothyroidism \[20 females and 4 males; mean age (+/- SE),
47.5 +/- 2.7 yr\] and 20 normal subjects (17 females and 3 males; age,
47.6 +/- 3.0 yr) were studied. In the first group of 12 hypothyroid
patients, administration of pyridostigmine, a cholinergic agonist drug
(120 mg, orally, at -60 min), notably increased GH responses to
GH-releasing hormone (GHRH; 1 microgram/kg, iv, at 0 min; peak GH levels
for pyridostigmine plus GHRH vs. placebo plus GHRH, 16.6 +/- 4.9 vs. 6.0
+/- 1.8 micrograms/L; P \< 0.01). The GH responses to pyridostigmine
plus GHRH, however, were considerably lower than those in 10 normal
subjects (peak GH levels, 53.0 +/- 3.5 micrograms/L; P \< 0.001). In the
second group of 12 hypothyroid patients, arginine infusion (30 g, iv,
from 0-30 min) markedly increased the GH responses induced by GHRH
administration (1 microgram/kg, iv, at 0 min; peak GH levels for
arginine plus GHRH vs. placebo plus GHRH, 30.6 +/- 4.7 vs. 5.3 +/- 1.0
micrograms/L; P \< 0.001). However, GH release after GHRH plus arginine
was greater in 10 normal subjects than in the hypothyroid patients (peak
GH levels, 50.9 +/- 5.3 micrograms/L; P \< 0.001). Pyridostigmine and
arginine inhibit hypothalamic somatostatin tone. The stimulatory effect
of both agents on GHRH-induced GH release indicates that reduced GH
secretion in hypothyroidism can be reversed to a considerable extent by
inhibiting hypothalamic somatostatinergic tone. The relatively greater
potency of arginine compared to pyridostigmine suggests that hypothyroid
patients may have an impairment of the cholinergic pathways.
Furthermore, these data show that hypothyroid patients have a
somatotrope secretory capacity much greater than previously thought.

468\. Vierhapper, H., A. Nardi, and C. Bieglmayer, *The use of the
pyridostigmine growth hormone-releasing hormone stimulation test to
detect growth hormone deficiency in patients with pituitary adenomas.*
Metabolism, 2002. 51(1): p. 34-7. The pyridostigmine (PD)/growth
hormone-releasing hormone (GHRH) stimulation test was used to determine
growth hormone (GH) secretion in patients with pituitary adenomas prior
to (n = 55) and after (n = 72) transsphenoidal adenomectomy, as well as
in 98 controls. In controls, maximum concentrations of GH showed a
strong negative relationship both with body mass index (BMI) and age.
Having calculated the 95% confidence intervals for maximum GH
concentrations to be expected for any given age and BMI according to a
statistical model, we compared these individually predicted ranges to GH
concentrations actually observed in patients with pituitary disease
during PD/GHRH stimulation. Preoperatively and postoperatively, a
maximum GH concentration below the calculated confidence intervals was
seen in 29 of 55 (52%) and in 57 of 72 (79%) of these patients,
respectively. In the remaining patients, maximum GH concentrations were
in or above the range defined by these confidence intervals. Our results
indicate that maximum concentrations of GH during the PD/GHRH test
depend to a large extent on the individuals\' age and BMI. The results
obtained with the PD/GHRH stimulation must, in each individual patient,
be compared with a large control group taking into account both age and
BMI. In individuals older then 55 years and with a BMI greater than 35
kg/(2), the diagnosis of GH deficiency cannot safely be made, at least
not with this test.

469\. Wang, X.D., C.Y. Pan, and Y.Z. Wang, *Application of
pyridostigmine in evaluation of growth hormone reserves in children and
adolescents.* Chin Med J (Engl), 1991. 104(6): p. 484-6. There is
evidence that the cholinergic system positively modulates growth hormone
(GH) secretion. In the present study, we observed the effects of
cholinergic enhancement by pyridostigmine (PD), a cholinesterases
inhibitor, on GH release in both normal (n = 13) and GH deficient
children and adolescents (n = 10). Responses of GH to insulin
hypoglycemia (Ins) were also observed. In the normal subjects,
PD-induced serum GH peak level was significantly higher than that
induced by Ins (P less than 0.01), while the GH level in the patients
with pituitary dwarfism showed no increase in both tests. This study
indicates that PD test may be considered a sensitive dynamic test in
evaluating pituitary function of GH secretion in children and
adolescents.

470\. Wehrenberg, W.B., *et al.*, *Pyridostigmine-mediated growth
hormone release: evidence for somatostatin involvement.* Endocrinology,
1992. 130(3): p. 1445-50. Pyridostigmine (PD), a cholinesterase
inhibitor, has been shown to elicit GH release when given alone and to
potentiate the GH response to GH-releasing hormone (GHRH) in man.
Numerous experiments have indirectly indicated that somatostatin (SS)
inhibition is its likely mechanism of action. This study sought to
establish the ability of PD to induce GH release in the rat, determine
the dose-response relationship, and test the hypothesis that SS
inhibition is the method of action. Three experiments were performed to
monitor the GH response to PD. I) Five groups of male rats were food
deprived for 72 h. The groups were then treated iv with saline, SS
antibody (SS-ab), and 10, 100, and 1000 micrograms/kg PD, respectively.
Blood samples were drawn before and after treatment. II) Two groups of
male rats were pretreated iv with GHRH antibody (GHRH-ab) and either
SS-ab or normal sheep serum (NSS). Blood samples were drawn every 30 min
for 8.5 h, during which time each animal was injected with PD (10
micrograms/kg) in the third hour and again in the sixth hour. III) Male
rats received a PD injection (10 micrograms/kg, iv) during a spontaneous
GH trough period and a second PD injection during a spontaneous GH peak
period. Blood samples were drawn at regular intervals preceding and
following treatments. In Exp I, PD induced a clear 4- to 5-fold increase
in GH concentrations in food-deprived rats. The maximal GH responses
occurred after the 10 and 100 micrograms/kg doses, although the pattern
and duration were different with these two doses. In Exp II, PD induced
an approximately 2-fold increase in GH values in animals pretreated with
GHRH-ab and NSS, but failed to induce a change in GH in the animals
treated with GHRH-ab and SS-ab. In Exp III, PD failed to induce any
change in GH concentration when administered during spontaneous GH peaks
or troughs. The first two experiments suggest that PD increases GH
secretion in the rat via inhibition of SS. The failure of PD to alter GH
during a spontaneous peak is consistent with the current hypothesis that
the level of SS is low at this time. Its failure to alter GH during
trough periods may be related to very high SS tone. In conclusion, our
results support the hypothesis that PD acts via inhibition of SS
secretion.

471\. Yang, I., *et al.*, *Combined
pyridostigmine-thyrotrophin-releasing hormone test for the evaluation of
hypothalamic somatostatinergic activity in healthy normal men.* Eur J
Endocrinol, 1995. 133(4): p. 457-62. Pyridostigmine (PST), a
cholinesterase inhibitor, induces a clear growth hormone (GH) release in
man by suppression of hypothalamic somatostatin (SRIH). Somatostatin
suppresses thyrotrophin (TSH) release in rats and men. Earlier studies
showed that the thryotrophin-releasing hormone (TRH)-induced TSH
response was not altered by 60-120 mg of PST. We studied whether a
larger dose (180 mg) of PST can increase the TSH response to TRH. Six
healthy young men were studied with the following six tests: (Test 1)
200 micrograms of TRH i.v.; (Test 2) 180 mg of PST po; (Test 3) three
different doses of PST (60, 120, 180 mg) + TRH; (Test 4) 100 micrograms
of octreotide (SMS) i.v.; (Test 5) SMS + TRH; (Test 6) PST + SMS + TRH.
A large dose of PST (180 mg) significantly augmented GH, TSH and
prolactin responses to TRH, while smaller doses of PST (60 and 120 mg)
did not significantly increase the responses of GH and TSH. While the
increased TRH-induced prolactin response by PST was not suppressed by
SMS, the increased responses of GH and TSH were suppressed remarkably by
SMS. Most of the subjects noticed a mild to moderate abdominal pain,
nausea and muscular fasciculation after the administration of a large
dose of PST administration. These data suggest that suppression of
hypothalamic SRIH secretion by 180 mg of PST can augment the TSH
response to TRH. However, the considerable side effects should be
minimized before clinical application of the combined PST-TRH test.

472\. Cochard, A., R. Guilhermet, and M. Bonneau, *Effects of arginine,
growth hormone-releasing hormone (GHRH) and neostigmine administered
singly or in paired combinations on growth hormone (GH) release in
pigs.* Reprod Nutr Dev, 1997. 37(5): p. 589-98. In human, arginine (ARG)
induces growth hormone (GH) release, probably via a decrease in
somatostatinergic tone. To assess the mechanism by which ARG mediates GH
release in pigs, the effects on plasma GH release of ARG (1 g/kg body
weight, infused between times -15 and -5 min), growth hormone-releasing
hormone (GHRH, 2 micrograms/kg, at time 0 min) and neostigmine, a
cholinesterase inhibitor (NEO, 50 micrograms/kg, at time 4 min),
administered intravenously singly or in paired combinations were
investigated in piglets between times -30 and 100 min. ARG and GHRH had
additive effects on GH release. No potentialization was observed between
the two treatments. GH response was higher following the combination of
NEO and GHRH treatments than after NEO or GHRH given alone. NEO had no
further effect on ARG-induced GH secretion. Therefore, our results
suggest that the mechanism by which ARG stimulates GH secretion in pig
is the same as in human.

473\. Ghigo, E., *et al.*, *Intranasal administration of neostigmine
potentiates both intravenous and intranasal growth hormone
(GH)-releasing hormone-induced GH release in short children.* J Clin
Endocrinol Metab, 1991. 72(2): p. 467-70. Administration of cholinergic
agonists increases both basal and GH-releasing hormone (GHRH)-induced GH
secretion, probably acting via inhibition of endogenous somatostatin
release. The aim of our study was to verify in two groups of children
with idiopathic short stature the effect of intranasal administration of
neostigmine (inNS; 3 mg), a cholinesterase inhibitor, on basal GH levels
as well as on the somatotroph response to GHRH when the peptide was
administered either iv (ivGHRH; 1 microgram/kg) or intranasally (inGHRH;
10 micrograms/kg). In group A (n = 6; age, 10.6-16.0 yr) inNS induced a
significant GH increase \[inNS vs. saline, area under the curve (AUC;
mean +/- SEM), 263.7 +/- 60.2 vs. 73.8 +/- 3.1 micrograms/L.h; P less
than 0.03\] and potentiated the somatotroph response to ivGHRH (inNS
with ivGHRH vs. ivGHRH, 1316 +/- 183.0 vs. 644.9 +/- 154.5
micrograms/L.h; P less than 0.03). In group B (n = 6; age, 11.5-15.9 yr)
ivGHRH induced a GH rise clearly higher than that induced by inGHRH
(604.2 +/- 154.3 vs. 137.1 +/- 28.2 micrograms/L.h; P less than 0.03).
Administration of inNS induced a GH rise similar to that occurring after
inGHRH (AUC, 239.2 +/- 69.5 micrograms/L.h) and markedly increased the
inGHRH-induced GH response (482.4 +/- 103.6 micrograms/L.h; P less than
0.05 and 0.03 vs. inNS and inGHRH, respectively), so that it overlapped
with that induced by ivGHRH alone. In conclusion, cholinergic agonists
such as neostigmine are able to increase both basal and GHRH-induced GH
secretion in short children even when given intranasally. Combined
intranasal administration of neostigmine and GHRH (10 micrograms/kg) is
able to induce a GH rise similar to that induced by ivGHRH alone (1
microgram/kg), suggesting the potential usefulness of this combination
cocktail and route of administration for the treatment of short stature.

474\. Gotoh, M., *et al.*, *Adrenocorticotropin and growth hormone
secretions after intracerebroventricular administration of neostigmine
in rats: their relationships to hypothalamic monoaminergic neuronal
activities.* Brain Res, 1994. 659(1-2): p. 259-62. Serum
adrenocorticotropic hormone (ACTH) and growth hormone (GH)
concentrations were assessed simultaneously with hypothalamic neuronal
activities of norepinephrine (NE), dopamine (DA), and serotonin (5-HT)
60 min after the third cerebroventricular administration of neostigmine
(a cholinesterase inhibitor) in awake rats. Serum ACTH and GH
concentrations were significantly increased and decreased, respectively.
Neostigmine caused significant increases in hypothalamic NE and DA
activities and a significant decrease in hypothalamic 5-HT activity. The
reciprocal changes of serum ACTH and GH concentrations were similar to
those of hypothalamic NE and 5-HT activities. Multiple regression
analyses with stepwise procedure revealed that hypothalamic NE and 5-HT
activities were respectively significant determinants of serum ACTH and
GH concentrations. Apart from the direct influence of neostigmine on
ACTH and GH secretions, it is suggested that the changes in hypothalamic
monoaminergic activities play an important role in modulating ACTH and
GH secretions following the administration of neostigmine.

475\. Magnan, E., *et al.*, *Neostigmine stimulates growth
hormone-releasing hormone release into hypophysial portal blood of
conscious sheep.* Endocrinology, 1993. 132(3): p. 1247-51. GH secretion
is stimulated by the administration of cholinesterase inhibitors (such
as pyridostigmine and neostigmine) in several species, including man. On
the basis of indirect experiments, it has been postulated that this
action is mediated by a decrease in hypothalamic somatostatin release.
We have investigated the effect of neostigmine in sheep, since it is
possible to collect hypophysial portal blood for GH-releasing hormone
(GHRH) and somatostatin determination in this species under a conscious
unstressed state. First, after i.v. injection of neostigmine (1 mg), a
significant increase in plasma GH levels and an unequivocal potentiation
of the GH response to GHRH were observed. Then, we observed that i.v.
injection of neostigmine (1 mg) induced an immediate, short-lasting (30
min), and marked increase in GHRH (126.1 +/- 17 vs. 14.5 +/- 2.1 pg/ml;
P \< 0.01) levels in hypophysial portal blood of rams chronically
implanted with perihypophysial cannulae. No change in somatostatin
secretion was recorded during the same period. These data suggest that
the stimulating effect of cholinergic drugs on GH secretion is mediated
by stimulation of GHRH release. A direct effect of neostigmine at the
level of pituitary gland is possible and may explain the potentiation of
GHRH-induced GH release.

476\. Magnan, E., *et al.*, *Effect of actively immunizing sheep against
growth hormone-releasing hormone or somatostatin on spontaneous
pulsatile and neostigmine-induced growth hormone secretion.* J
Endocrinol, 1995. 144(1): p. 83-90. The physiological role of endogenous
circulating GH-releasing hormone (GHRH) and somatostatin (SRIH) on
spontaneous pulsatile and neostigmine-induced secretion of GH was
investigated in adult rams actively immunized against each neuropeptide.
All animals developed antibodies at concentrations sufficient for
immunoneutralization of GHRH and SRIH levels in hypophysial portal
blood. In the anti GHRH group, plasma GH levels were very low; the
amplitude of GH pulses was strikingly reduced, although their number was
unchanged. No stimulation of GH release was observed after neostigmine
administration. The reduction of GH secretion was associated with a
decreased body weight and a significant reduction in plasma IGF-I
concentration. In the anti-SRIH group, no changes in basal and pulsatile
GH secretion or the GH response to neostigmine were observed as compared
to controls. Body weight was not significantly altered and plasma IGF-I
levels were reduced in these animals. These results suggest that in
sheep, circulating SRIH (in the systemic and hypophysial portal
vasculature) does not play a significant role in pulsatile and
neostigmine-induced secretion of GH. The mechanisms of its influence on
body weight and production of IGF-I remain to be determined.

477\. Joyce, P.R., R.A. Donald, and M.G. Nicholls, *Physostigmine
reduces the plasma cortisol response to methylphenidate in normal
subjects.* J Psychiatr Res, 1986. 20(2): p. 151-7. Six healthy male
subjects were studied to determine whether the reduced plasma cortisol
response to methylphenidate observed in depressed patients could be
reproduced in normal subjects by pretreatment with physostigmine.
Indeed, physostigmine was found to mimic this effect. The finding raises
the possibility that increased cholinergic rather than decreased
adrenergic activity could explain the blunted cortisol response to
stimulants reported in depressed patients. Physostigmine also enhanced
the growth hormone rise and prolactin decline, and limited the increase
in heart rate following methylphenidate administration.

478\. Steinberg, B.J., *et al.*, *Depressive response to physostigmine
challenge in borderline personality disorder patients.*
Neuropsychopharmacology, 1997. 17(4): p. 264-73. The purpose of this
study was to examine the relationship between mood and hormonal
responses to cholinergic challenge with physostigmine in order to assess
cholinergic system responsiveness in borderline personality disorder
(BPD) patients, other non-BPD personality disorder patients, and normal
controls. Thirty-four personality disorder patients, 10 of whom met
criteria for BPD and 24 of whom met criteria for other, non-borderline,
personality disorders, and 11 normal controls participated in a double
blind, placebo controlled physostigmine challenge paradigm. The Profile
of Mood States depression subscale (POMS-D) self report measure was
obtained at baseline and following the physostigmine or placebo
infusions. A repeated measures ANOVA of POMS-D scores in placebo and
drug conditions indicated a significantly greater depressive response in
the total cohort of personality disorder patients than in the normal
comparison group (p \< 0.05). However, the depressive response to
physostigmine was significantly greater in BPD patients, but not other
personality disorder patients, compared to normal controls (p \< 0.05).
There was a correlation between the peak placebo-corrected depressive
response to physostigmine and a group of BPD traits related to affective
instability but not a group of BPD traits related to impulsivity. There
was no correlation in any group between mood response to physostigmine
and changes in plasma cortisol, prolactin, or growth hormone, or to
nausea or other side effects following physostigmine infusion. These
data suggest that there is an association between BPD and acute
depressive responses to physostigmine challenge, and that the
cholinergic system may be involved in the regulation of affect in Axis
II disorders.

479\. Karczmar, A., *Invited review: Anticholinesterases: dramatic
aspects of their use and misuse.* Neurochem Int, 1998. 32(5-6): p.
401-11. While the lore of anticholinesterases (antiChEs), particularly
physostigmine and its natural source, the Calabar bean, is a subject of
ethnomedicine and predates our scientific era, the pharmacological
development of physostigmine analogues and related agents and of the
antiChEs of the organophosphorus (OP) type, is a matter of the last two
centuries; this development has reached an exponential character in the
last fifty years. This explosion relates to certain uses and misuses of
these drugs and this aspect of antiChEs is the main focus of this
article. Firstly, there is the matter of Senile Dementia of Alzheimer\'s
Type (SDAT); while there are several clinical applications of antiChEs,
their employment in the treatment of SDAT is the last and most intense
foray in their medical history and this article will focus on the uses
and misuses of antiChEs in this area. Secondly, the applied use of
antiChEs as insecticides which coincided with the historical development
of OP antiChEs was and is, of major significance for the agricultural
economy of both advanced and underdeveloped countries, as this
employment may mean the difference between life and starvation. However,
there are notable dangers with this application of OP drugs, as will be
emphasized in this article. Thirdly, there is the significant and tragic
development of the OP drugs as warfare agents and tools for terrorists
and rogue states and this article will discuss the several types of
toxicity of OP agents and their mechanisms, the enigma of the Persian
Gulf War Syndrome being particularly stressed. Altogether, the immense
range of antiChE topics includes areas of great basic interest and of
practical applications that are of significant benefit to mankind as
well as of potential danger.

480\. Auriacombe, S., *et al.*, *Efficacy and safety of rivastigmine in
patients with Alzheimer\'s disease who failed to benefit from treatment
with donepezil.* Curr Med Res Opin, 2002. 18(3): p. 129-38. BACKGROUND:
Selective acetylcholinesterase (AChE) and dual acetyl- and
butyrylcholinesterase inhibitors constitute the only approved agents for
the symptomatic treatment of Alzheimer\'s disease (AD). Donepezil is a
specific, reversible inhibitor of AChE, while rivastigmine is a slowly
reversible (pseudoirreversible) dual cholinesterase (ChE) inhibitor,
with brain-regional specificity for the cerebral cortex and hippocampus.
According to the European Marketing Authorisations, the clinical benefit
of ChE inhibitors should be reassessed on a regular basis and
discontinuation should be considered when evidence of a therapeutic
effect is no longer present. However, substantial differences in the
pharmacological and pharmacokinetic profiles of the available ChE
inhibitors suggest that it may be desirable to switch between ChE
inhibitors if patients fail to show efficacy, deteriorate or are unable
to tolerate their initially prescribed medication. DESIGN: This
open-label, six-month study evaluated the efficacy and safety of
rivastigmine in 382 AD patients who had previously failed to benefit
from treatment with donepezil (80% due to lack of efficacy, 11% due to
tolerability problems, 9% both reasons). RESULTS: At the end of the
study, 56.2% of patients were responders to rivastigmine, as assessed
using a global function scale (the Clinicians\' Global Impression of
Change). Cognitive performance (measured by the Mini-Mental State
Examination) and the ability to perform activities of daily living
(measured by the Instrumental Activities of Daily Living scale) were
improved/stabilised in 48.9% and 57.0% of patients, respectively.
Rivastigmine was generally well tolerated, the most common adverse
events being nausea and vomiting, consistent with reports from previous
clinical studies. The occurrence of side-effects or lack of efficacy
with donepezil treatment was not a predictor of similar problems when
treated with rivastigmine. CONCLUSION: Rivastigmine treatment appears to
be beneficial in AD patients who have previously failed to benefit from,
or were unable to tolerate treatment with, donepezil.

481\. Badia, A., *et al.*, *Synthesis and evaluation of
tacrine-huperzine A hybrids as acetylcholinesterase inhibitors of
potential interest for the treatment of Alzheimer\'s disease.* Bioorg
Med Chem, 1998. 6(4): p. 427-40. Seventeen polycyclic compounds related
to tacrine and huperzine A have been prepared as racemic mixtures and
tested as acetylcholinesterase (AChE) inhibitors. The conjunctive
pharmacomodulation of huperzine A (carbobicyclic substructure) and
tacrine (4-aminoquinoline substructure) led to compound 7jy, 2.5 times
less active than tacrine as AChE inhibitor, but much more active than
its (Z)-stereoisomer (7iy). Derivatives 7dy and 7ey, lacking the
ethylidene substituent, showed to be more active than tacrine. Many
other structural modifications of 7jy led to less active compounds.
Compounds 7dy and 7ey also showed to be much more active than tacrine in
reversing the partial neuromuscular blockade induced by d-tubocurarine.

482\. Ballard, C.G., *Advances in the treatment of Alzheimer\'s disease:
benefits of dual cholinesterase inhibition.* Eur Neurol, 2002. 47(1): p.
64-70. Cholinesterase inhibitors have produced the best evidence of
clinical efficacy for treating patients with Alzheimer\'s disease (AD).
Many of these drugs selectively inhibit acetylcholinesterase (AChE), but
agents that also target butyrylcholinesterase (BuChE) may provide added
benefits. As AD progresses, ACh regulation may become increasingly
dependent on BuChE and dual inhibitors may provide more sustained
efficacy than AChE-selective agents. Dual inhibition may also help to
slow the formation of amyloidogenic compounds, providing an important
disease-modifying mechanism. Rivastigmine is a dual inhibitor that has
demonstrated benefits across the spectrum of AD severity and across the
cognitive, functional and behavioural domains of AD. It is a priority
for future clinical trials to determine whether agents with dual
inhibition properties have greater clinical efficacy.

483\. Bar-On, P., *et al.*, *Kinetic and structural studies on the
interaction of cholinesterases with the anti-Alzheimer drug
rivastigmine.* Biochemistry, 2002. 41(11): p. 3555-64. Rivastigmine, a
carbamate inhibitor of acetylcholinesterase, is already in use for
treatment of Alzheimer\'s disease under the trade name of Exelon.
Rivastigmine carbamylates Torpedo californica acetylcholinesterase very
slowly (k(i) = 2.0 M(-1) min(-1)), whereas the bimolecular rate constant
for inhibition of human acetylcholinesterase is \>1600-fold higher (k(i)
= 3300 M(-1) min(-1)). For human butyrylcholinesterase and for
Drosophila melanogaster acetylcholinesterase, carbamylation is even more
rapid (k(i) = 9 x 10(4) and 5 x 10(5) M(-1) min(-1), respectively).
Spontaneous reactivation of all four conjugates is very slow, with \<10%
reactivation being observed for the Torpedo enzyme after 48 h. The
crystal structure of the conjugate of rivastigmine with Torpedo
acetylcholinesterase was determined to 2.2 A resolution. It revealed
that the carbamyl moiety is covalently linked to the active-site serine,
with the leaving group, (-)-S-3-\[1-(dimethylamino)ethyl\]phenol, being
retained in the \"anionic\" site. A significant movement of the
active-site histidine (H440) away from its normal hydrogen-bonded
partner, E327, was observed, resulting in disruption of the catalytic
triad. This movement may provide an explanation for the unusually slow
kinetics of reactivation.

484\. Barner, E.L. and S.L. Gray, *Donepezil use in Alzheimer disease.*
Ann Pharmacother, 1998. 32(1): p. 70-7. OBJECTIVE: To review the
pharmacology, pharmacokinetics, clinical efficacy, adverse effects,
drug-drug interactions, and the therapeutic issues concerning the use of
donepezil in patients with Alzheimer disease. DATA SOURCES: Published
articles and abstracts in English were identified by MEDLINE (January
1985-July 1997) searches using the search terms donepezil, E2020,
treatment of Alzheimer\'s disease, and cholinesterase inhibitors.
Additional articles were identified from the bibliographies of the
retrieved articles. Data were also obtained from approved product
labeling. DATA EXTRACTION: The literature was assessed for adequate
description of patients, methodology, and outcomes. DATA SYNTHESIS:
Donepezil is a cholinesterase inhibitor that is selective and specific
for acetylcholinesterase. It is metabolized by hepatic isoenzymes CYP2D6
and CYP3A4 and undergoes glucuronidation. Information about drug
interactions is limited, but a potential for drug-drug interactions does
exist, given the route of elimination. Donepezil has a relative
bioavailability of 100% following oral administration and is not
affected by the presence of food. In 15- and 30-week trials, donepezil
was effective in patients with mild-to-moderate Alzheimer disease as
shown by improvements on standard assessment instruments (i.e., the
Alzheimer\'s Disease Assessment Scale-Cognitive Subscale, the Clinical
Interview-Based Impression of Change with Caregiver Input). Adverse
effects were comparable with those of placebo, and monitoring of liver
function tests is not required. CONCLUSIONS: Donepezil is an effective
symptomatic treatment for some patients with mild-to-moderate Alzheimer
disease. Although no comparative trials have been reported, donepezil
appears to be a safe alternative for tacrine, given its convenient
once-daily dosing, minimal adverse effects, and lower total cost.

485\. Bartolucci, C., *et al.*, *Three-dimensional structure of a
complex of galanthamine (Nivalin) with acetylcholinesterase from Torpedo
californica: implications for the design of new anti-Alzheimer drugs.*
Proteins, 2001. 42(2): p. 182-91. The 3D structure of a complex of the
anti-Alzheimer drug galanthamine with Torpedo californica
acetylcholinesterase is reported. Galanthamine, a tertiary alkaloid
extracted from several species of Amarylidacae, is so far the only drug
that shows a dual activity, being both an acetylcholinesterase inhibitor
and an allosteric potentiator of the nicotinic response induced by
acetylcholine and competitive agonists. The X-ray structure, at 2.5A
resolution, shows an unexpected orientation of the ligand within the
active site, as well as unusual protein-ligand interactions. The
inhibitor binds at the base of the active site gorge, interacting with
both the acyl-binding pocket and the principal quaternary
ammonium-binding site. However, the tertiary amine group of galanthamine
does not directly interact with Trp84. A docking study using the program
AUTODOCK correctly predicts the orientation of galanthamine in the
active site. The docked lowest-energy structure has a root mean square
deviation of 0.5A with respect to the corresponding crystal structure of
the complex. The observed binding mode explains the affinities of a
series of structural analogs of galanthamine and provides a rational
basis for structure-based drug design of synthetic derivatives with
improved pharmacological properties. Proteins 2001;42:182-191.

486\. Becker, R.E., *et al.*, *Double-blind, placebo-controlled study of
metrifonate, an acetylcholinesterase inhibitor, for Alzheimer disease.*
Alzheimer Dis Assoc Disord, 1996. 10(3): p. 124-31. Fifty patients with
probable Alzheimer disease (AD) completed a 3-month double-blind study
to compare metrifonate to placebo. We dosed metrifonate to achieve a
40-60% inhibition of red blood cell acetylcholinesterase activity. The
Alzheimer Disease Assessment Scale cognitive subscale score (ADAS-C)
served as the primary outcome measure. At the completion of 3 months of
treatment, the metrifonate group ADAS-C score differed significantly
from the placebo group score by 2.6 points (p \< 0.01). A 0.75-point
trend toward improvement occurred during treatment in the ADAS cognitive
performance of the metrifonate group (p = 0.15), and a 1.10-point
deterioration in cognitive performance was found in the placebo group (p
\< 0.02). On the Global Improvement Scale (GIS), the two groups differed
significantly on their changes from baseline to treatment phase (p \<
0.02). Significant deterioration occurred in GIS scores (p \< 0.01) and
in Mini Mental State Examination (MMSE) scores (p \< 0.03) in the
placebo-treated group. Adverse effects were uncommon and did not require
adjustment of the dose of metrifonate or discontinuation of treatment.
We achieved a mean of 52.3% decrease in red blood cell
acetylcholinesterase activity. During up to 18 months of subsequent open
metrifonate treatment of patients, we found a deterioration of 1.68
points per year in MMSE performance. These findings support further
study of the effects of metrifonate on deterioration rate in AD.

487\. Bores, G.M., *et al.*, *Pharmacological evaluation of novel
Alzheimer\'s disease therapeutics: acetylcholinesterase inhibitors
related to galanthamine.* J Pharmacol Exp Ther, 1996. 277(2): p. 728-38.
Acetylcholinesterase (AChE) inhibitors from several chemical classes
have been tested for the symptomatic treatment of Alzheimer\'s disease;
however, the therapeutic success of these compounds has been limited.
Recently, another AChE inhibitor, galanthamine hydrobromide (GAL), has
shown increased clinical efficacy and safety. Using biochemical,
behavioral and pharmacokinetic analyses, this report compares GAL with
two of its analogs, 6-O-acetyl-6-O-demethylgalanthamine hydrochloride
(P11012) and 6-O-demethyl-6-O\[(adamantan-1-yl)-carbonyl\]galanthamine
hydrochloride (P11149), for their therapeutic potential. P11012 and
P11149 were found to be potent, competitive and selective inhibitors of
AChE, demonstrating central cholinergic activity, behavioral efficacy
and safety. P11012 and P11149, though pharmacokinetic analyses, were
shown to act as pro-drugs, yielding significant levels of
6-O-demethylgalanthamine. In vitro, 6-O-demethylgalanthamine was 10- to
20-fold more potent than GAL as an inhibitor of AChE, and it
demonstrated greater selectivity for inhibition of AChE vs.
butyrylcholinesterase. Like GAL, both P11012 and P11149 showed central
cholinergic activity biochemically, by significantly inhibiting rat
brain AChE; physiologically, by causing hypothermia; and behaviorally,
by attenuating scopolamine-induced deficits in passive avoidance. In
addition, GAL, P11012 and P11149 enhanced step-down passive avoidance,
another measure of behavioral efficacy. By comparing efficacious doses
with primary overt effects, P11012 and P11149 had better oral
therapeutic indices than GAL. Oral pharmacokinetic analyses of GAL,
P11012 and P11149 revealed differences. Although P11012 and P11149
exhibited similar area under the curve values, 191149 had slower, lower
and more sustained concentration maximum levels. P11012 and GAL rapidly
reached their concentration maximums, but GAL, in brain had the highest
area under the curve and concentration maximum. Because of its composite
profile, including duration of action, oral therapeutic index and
pharmacokinetics, P11149 is considered the better therapeutic candidate
for the treatment of Alzheimer\'s disease.

488\. Borroni, B., *et al.*, *Amyloid precursor protein in platelets of
patients with Alzheimer disease: effect of acetylcholinesterase
inhibitor treatment.* Arch Neurol, 2001. 58(3): p. 442-6. BACKGROUND:
Amyloid precursor protein (APP) forms with apparent molecular weights of
130, 110, and 106 kd are present in human platelets. It has been
demonstrated that Alzheimer disease (AD) is specifically associated with
a decreased APP forms ratio in platelets. OBJECTIVE: To investigate
whether acetylcholinesterase (AChE) inhibitor treatment modifies the
ratio of platelet APP forms in patients with AD. PATIENTS AND METHODS:
From a large sample of patients with probable AD, 30 with mild to
moderate AD were selected. Each patient underwent a clinical evaluation
including the Mini-Mental State Examination (MMSE) and platelet APP
forms analysis at baseline and after 30 days. During this interval, 20
of 30 patients with AD were treated with donepezil hydrochloride (5
mg/d), a piperidine phosphate-based cholinesterase inhibitor. Platelets
were subjected to Western blot analysis using monoclonal antibody
(22C11). The ratio between the immunoreactivity of the
higher-molecular-weight APP form (130 kd) and the lower forms (106 and
110 kd) was measured. RESULTS: All patients taking donepezil completed
the 30 days of treatment without adverse effects. The platelet APP forms
ratio at baseline did not differ between the 2 AD groups (mean +/- SD
optical density ratio: untreated AD, 0.47 +/- 0.12; treated AD, 0.38 +/-
0.18), whereas a significant difference was found at follow-up (mean +/-
SD optical density ratio: untreated AD, 0.45 +/- 0.17; treated AD, 0.77
+/- 0.29; P\<.001). A significant improvement in MMSE scores in treated
AD patients was observed from baseline (16.9 +/- 3.8) to 30 days (18.9
+/- 4.42) (P\<.009, 30 days vs baseline), but no significant correlation
was found in treated AD patients between MMSE score improvement and APP
forms/ratio increase (P =.09). CONCLUSIONS: Administration of AChE
inhibitors increases the ratio of APP forms in platelets of patients
with AD, suggesting a potential effect of AChE inhibitors on APP
trafficking or processing in a peripheral cell.

489\. Borroni, B., *et al.*, *ApoE genotype influences the biological
effect of donepezil on APP metabolism in Alzheimer disease: evidence
from a peripheral model.* Eur Neuropsychopharmacol, 2002. 12(3): p.
195-200. Three major amyloid precursor protein (APP) forms with apparent
molecular weight ranging from 106 to 130 kDa are present in human
platelets. Alzheimer disease (AD) is associated with a decreased APP
forms ratio (APPr) between the three major forms. A total of 25 mild to
moderate AD patients were investigated. Platelet APPr was studied before
and after 30 days of acetylcholinesterase-inhibitor treatment
(donepezil, 5 mg daily). Patients were grouped into non-epsilon4
carriers and epsilon4 carriers according to apolipoprotein E (ApoE)
genotype. At baseline, all patients showed low APPr levels and no
significant difference was found between the two ApoE subgroups. After
treatment, although a marked improvement in APPr was observed in most
patients, non-epsilon4 carriers displayed a higher increase compared to
epsilon4 carriers (P\<0.0001). The present study provides evidence that
donepezil influences APP metabolism in platelets, and suggests that ApoE
genotype might be an important modulating factor for drug responsiveness
in AD.

490\. Bottino, C.M., *et al.*, *\[Cognitive rehabilitation in
Alzheimer\'s disease patients: multidisciplinary team report\].* Arq
Neuropsiquiatr, 2002. 60(1): p. 70-9. OBJECTIVE: This study aims to show
preliminary results of the \'combined treatment\' (acetylcholinesterase
inhibitor + cognitive training) on a group of mild Alzheimer\'s disease
(AD) patients, followed-up for 7 months. METHODS: Six mild AD patients,
diagnosed according to ICD-10 and NINCDS-ADRDA criteria, were included
on a open trial with Rivastigmine, 6-12 mg/day, for 2 months, followed
by a weekly cognitive rehabilitation group, for 5 months. Caregivers
were submitted to a weekly group of counseling and support for 5 months.
RESULTS: Stabilization or mild improvement of patients\' cognitive and
activities of daily living deficits were found, besides reduction of
patients and caregivers\' depressive and anxiety levels. CONCLUSION: The
\'combined treatment\' can help on the stabilization or result on a mild
improvement of AD patients\' cognitive and functional deficits. Support
and counseling interventions can reduce the levels of caregivers\'
psychiatric symptoms.

491\. Bronfman, F.C., *et al.*, *Laminin blocks the assembly of
wild-type A beta and the Dutch variant peptide into Alzheimer\'s
fibrils.* Amyloid, 1998. 5(1): p. 16-23. Amyloid fibril formation is
believed to be a nucleation-dependent polymerization process which may
be influenced by various other factors with important consequences for
the development, prevention or treatment of amyloidosis. We have
previously shown that laminin inhibits A beta peptide fibril formation
in vitro. Here we present a kinetic study that indicates laminin to be a
potent anti-amyloidosis factor, as it not only inhibited A beta 1-40
fibril aggregation, but also inhibited the aggregation of the Dutch A
beta 1-40 variant, a peptide with a higher capacity to aggregate than
the wild-type A beta 1-40. The inhibitory effect of laminin on amyloid
fibril formation was not overcome by the addition of pre-formed A beta
fibrils, suggesting that laminin inhibits the fibril elongation process.
At the present time, however, we cannot rule out the possibility that
laminin also affects the initial nucleation process of A beta fibril
formation. On other hand, laminin was not able to counteract the amyloid
fibril formation promoted by acetylcholinesterase (AChE), another
component of the amyloid deposits found in AD brains. The effect of
laminin may be important as an inhibitor of A beta amyloidogenesis in
vivo, specifically at the level of cerebral blood vessels.

492\. Brufani, M., M. Marta, and M. Pomponi, *Anticholinesterase
activity of a new carbamate, heptylphysostigmine, in view of its use in
patients with Alzheimer-type dementia.* Eur J Biochem, 1986. 157(1): p.
115-20. The anticholinesterase activity of a new carbamate,
heptylphysostigmine, was studied in vitro. This compound is a
competitive inhibitor of acetylcholinesterase (or true cholinesterase)
having Ki = (1 +/- 0.5) X 10(-7) M. The inhibition was instantaneous at
the onset and did not diminish with prolonged incubation of the drug and
enzyme.

493\. Burov Iu, V., T.D. Baimanov, and N.I. Maisov, *\[Effects of
amiridin and tacrine, drugs effective in Alzheimer\'s disease, on
synaptosomal uptake of neuromediators\].* Biull Eksp Biol Med, 1992.
113(4): p. 379-81. The study of the drugs effective in the treatment of
cognitive deficits and memory loss associated with senile dementia of
the Alzheimer\'s type\--tacrine and amiridin, acetylcholinesterase
inhibitor physostigmine and nootrop piracetam on uptake of 3H-serotonin
(3H-5-HT), 3H-adrenaline (3H-AD), 3H-noradrenaline (3H-HA), 2H-dopamine
(3H-DA), 3H-gamma-aminobutyric acid (3H-GABA), 3H-glutamic acid
(3H-GLU), 3H-aspartic acid (3H-ASP) and 3H-glycine (3H-GLI) showed that
tacrine and amiridin (5 x 10(-5) M) statistically significantly (P less
than 0.05) inhibited the uptake of 3H-DA and 3H-5-HT. Physostigmine at
concentration 5 x 10(-4) M statistically significantly (P less than
0.05) inhibited uptake of 3H-5-HT only. Piracetam at concentration range
1-5 x 10(-3) M had no effect on uptake of all investigated
neurotransmitters. The above finding suggest that the uptake of
neurotransmitter in nerve terminals is not the main target of amiridin
and tacrine.

494\. Camps, P., *et al.*, *New tacrine-huperzine A hybrids (huprines):
highly potent tight-binding acetylcholinesterase inhibitors of interest
for the treatment of Alzheimer\'s disease.* J Med Chem, 2000. 43(24): p.
4657-66. Several new 12-amino-6,7,10,11-tetrahydro-7,
11-methanocycloocta\[b\]quinoline derivatives (tacrine-huperzine A
hybrids, huprines) have been synthesized and tested as
acetylcholinesterase (AChE) inhibitors. All of the new compounds contain
either a methyl or ethyl group at position 9 and one or two (chloro,
fluoro, or methyl) substituents at positions 1, 2, or 3. Among the
monosubstituted derivatives, the more active are those substituted at
position 3, their activity following the order 3-chloro \> 3-fluoro \>
3-methyl \> 3-hydrogen. For the 1,3-difluoro and 1,3-dimethyl
derivatives, the effect of the substituents is roughly additive. No
significant differences were observed for the inhibitory activity of
9-methyl vs 9-ethyl derivatives mono- or disubstituted at positions 1
and/or 3. The levorotatory enantiomers of these hybrid compounds are
much more active (eutomers) than the dextrorotatory forms (distomers) as
AChE inhibitors. Compounds rac-20, (-)-20, rac-26, (-)-26, rac-30,
(-)-30, and rac-31 showed human AChE inhibitory activities up to
28.5-fold higher than for the corresponding bovine enzyme. Also, rac-19,
(-)-20, (-)-30, and rac-31 were very selective for human AChE vs
butyrylcholinesterase (BChE), the AChE inhibitory activities being
438-871-fold higher than for BChE. Several hybrid compounds, specially
(-)-20 and (-)-30, exhibited tight-binding character, showing higher
activity after incubation of the enzyme with the inhibitor than without
incubation, though the reversible nature of the enzyme-inhibitor
interaction was demonstrated by dialysis. The results of the ex vivo
experiments also supported the tight-binding character of compounds
(-)-20 and (-)-30 and showed their ability to cross the blood-brain
barrier. Molecular modeling simulations of the AChE-inhibitor complex
provided a basis to explain the differences in inhibitory activity of
these compounds.

495\. Camps, P., *et al.*, *Huprine X is a novel high-affinity inhibitor
of acetylcholinesterase that is of interest for treatment of
Alzheimer\'s disease.* Mol Pharmacol, 2000. 57(2): p. 409-17. Inhibitors
of the enzyme acetylcholinesterase (AChE) slow and sometimes reverse the
cognitive decline experienced by individuals with Alzheimer\'s disease.
Huperzine A, a natural product used in traditional Chinese herbal
medicine, and tacrine (Cognex) are among the potent AChE inhibitors used
in this treatment, but the search for more selective inhibitors
continues. We report herein the synthesis and characterization of
(-)-12-amino-3-chloro-9-ethyl-6,7,
10,11-tetrahydro-7,11-methanocycloocta\[b\]quinoline hydrochloride
(huprine X), a hybrid that combines the carbobicyclic substructure of
huperzine A with the 4-aminoquinoline substructure of tacrine. Huprine X
inhibited human AChE with an inhibition constant K(I) of 26 pM,
indicating that it binds to this enzyme with one of the highest
affinities yet reported. Under equivalent assay conditions, this
affinity was 180 times that of huperzine A, 1200 times that of tacrine,
and 40 times that of E2020 (donepezil, Aricept), the most selective AChE
inhibitor currently approved for therapeutic use. The association and
dissociation rate constants for huprine X with AChE were determined, and
the location of its binding site on the enzyme was probed in competition
studies with the peripheral site inhibitor propidium and the acylation
site inhibitor edrophonium. Huprine X showed no detectable affinity for
the edrophonium-AChE complex. In contrast, huprine X did form a ternary
complex with propidium and AChE, although its affinity for the free
enzyme was found to be 17 times its affinity for the propidium-AChE
complex. These data indicated that huprine X binds to the enzyme
acylation site in the active site gorge but interferes slightly with the
binding of peripheral site ligands.

496\. Canal, N. and B.P. Imbimbo, *Relationship between pharmacodynamic
activity and cognitive effects of eptastigmine in patients with
Alzheimer\'s disease. Eptastigmine Study Group.* Clin Pharmacol Ther,
1996. 60(2): p. 218-28. OBJECTIVE: To assess the safety, tolerability,
pharmacodynamics, and preliminary efficacy of eptastigmine, a new
long-acting cholinesterase inhibitor, in patients with probable
Alzheimer\'s disease. METHODS: This was a double-blind, randomized,
placebo-controlled, unbalanced parallel-group study. One-hundred and
three patients (83 in the eptastigmine group and 20 in the placebo
group) were recruited by 10 centers. Patients received 20 mg
eptastigmine or placebo for 4 weeks with twice-a-day or
three-times-a-day regimens, depending on body weight (\< or = 65 kg or
\> 65 kg, respectively). Patient performance on the Logical Memory Test,
Semantic Word Fluency Test, Trail Making Test, Index of Independence in
Activities of Daily Living, Instrumental Activities of Daily Living
Scales (IADL), and the Physician and Caregiver Clinical Global
Impression of Change (CGIC) was assessed at baseline and at the end of
treatment. RESULTS: Nine patients, all from the eptastigmine group, did
not complete treatment because of uncooperativeness (n = 3), adverse
events (n = 3), protocol violations (n = 2), and clinical decline (n =
1). Twenty-five patients receiving eptastigmine (34%) reported adverse
events mainly of the cholinergic type. Cholinergic side effects were
generally associated with peak red blood cell cholinesterase inhibition
exceeding 50% after the first dose, or 70% at steady state. At steady
state, average daily acetylcholinesterase inhibition ranged from 13% to
54%. Overall, 34% of patients receiving eptastigmine versus 0% receiving
placebo (p = 0.006) improved on the Physician CGIC. This percentage
increased to 46% in the subgroup of patients with average daily
acetylcholinesterase inhibition ranging from 30% to 35%. Patient
performance on the IADL also improved significantly compared with the
placebo group (p = 0.019). In the eptastigmine group, performances on
all tests and scales improved with an inverted U-shaped relation to
average daily acetylcholinesterase inhibition. CONCLUSIONS: This study
shows that doses of 40 to 60 mg per day of eptastigmine are relatively
safe and well tolerated and that moderate acetylcholinesterase
inhibition is associated with maximal cognitive efficacy.

497\. Carnero Pardo, C., *\[Are the new drugs for treatment of
Alzheimer\'s disease useful?\].* Rev Neurol, 2001. 32(2): p. 176-9. In
recent years several acetylcholinesterase inhibitor drugs have been
developed for the treatment of Alzheimer s disease. These are expensive
and their usefulness is doubtful. OBJECTIVE. We wish to review the
evidence available with regard to the efficacy and effectiveness of the
anticholinesterase drugs permitted in Spain. DEVELOPMENT. We review the
controlled clinical trials, systematic reviews and meta-analysis
published on the anticholinesterases permitted in Spain (tacrine,
donepezil and rivastingmine), and also the publications on their
effectiveness and efficacy. CONCLUSIONS. The evidence available seems to
show that these drugs are effective in producing modest but real
cognitive improvement in persons with mild and moderate Alzheimer s
disease (Type 1 evidence). Cognitive improvement has also been observed
in everyday clinical practice. Use of these drugs may be associated with
a reduction in the costs associated with this disease. These drugs are
useful and should be used in persons with mild or moderate Alzheimer s
disease, without any contra-indication.

498\. Chong, Y.H. and Y.H. Suh, *Amyloidogenic processing of
Alzheimer\'s amyloid precursor protein in vitro and its modulation by
metal ions and tacrine.* Life Sci, 1996. 59(7): p. 545-57. Recent
studies implicate that excessive amyloidogenic pathway of amyloid
precursor protein (APP) processing may be the final common pathway
involved in the pathogensis of AD. In attempts to identify the proteases
or factors leading to excessive amyloid deposition, we evaluated the
potential role of acethylcholinesterase (AChE) and its associated
protease for amyloidogenic processing of APP in vitro. Prolonged
incubation of a recombinant APP770 with AChE produced several
amyloidogenic fragments accumulating a relatively stable a 18 kDa A beta
(amyloid beta-protein) bearing carboxy terminal peptide, which was
further degraded by an increased concentration of AChE. Protease
inhibitory profiles confirmed the trypsin-like serine protease activity
present in AChE preparation. This observed APP processing was
significantly enhanced by Ca2+, Mg2+, or Mn2+ at 1 mM concentration and
modulated in concentration dependent manners by metal ions such as Ca2+,
Zn2+, Fe2+/Fe3+, Al3+, or a tacrine, a centrally active cholinesterase
inhibitor. Our data imply that AChE and its associated protease may be
involved in the generation a 18 kDa amyloidogenic peptide under certain
physiological condition in vivo and that the gradual changes in their
proteolytic activities or locations and the locally disturbed metal
homeostasis could be factors associated with abnormal accumulation of
APP, eventually leading to amyloid deposition in AD brain. In addition,
zinc or tacrine treatment of AD patients with high dosage or in the long
term may have effects on the process of amyloidogensis.

499\. Costagli, C. and A. Galli, *Inhibition of
cholinesterase-associated aryl acylamidase activity by
anticholinesterase agents: focus on drugs potentially effective in
Alzheimer\'s disease.* Biochem Pharmacol, 1998. 55(10): p. 1733-7. The
potency of a series of anticholinesterase (anti-ChE) agents and
serotonin-related amines as inhibitors of the aryl acylamidase (AAA)
activity associated with electric eel acetylcholinesterase (AChE) (EC
3.1.1.7) and horse serum butyrylcholinesterase (BuChE) (EC 3.1.1.8) was
examined and compared with the potency of the same compounds as ChE
inhibitors. Neostigmine, physostigmine, BW 284C51, (+/-)-huperzine A,
E2020, tacrine, edrophonium and heptyl-physostigmine were, in that
order, the most potent in inhibiting eel AChE-associated AAA activity,
their inhibitor constant (Ki) values being in the range 0.02-0.37
microM. The rank order of the same compounds as AChE inhibitors
basically paralleled that of AAA, although they were in general stronger
on AChE (Ki = 0.001-0.05). The peripheral anionic site inhibitors
propidium and gallamine were inactive on AChE-associated AAA. Serotonin
and its derivatives were slightly stronger on AAA (Ki = 7.5-30 microM)
than on AChE (Ki = 20-140 microM). Tacrine (IC50 = 0.03 microM),
diisopropylfluorophosphate (IC50 = 0.04 microM), heptyl-physostigmine
(IC50 = 0.11 microM), physostigmine (IC50 = 0.15 microM) and
tetra-iso-propylpyrophosphoramide (iso-OMPA) (IC50 = 0.75 microM) were
the most potent in inhibiting horse serum BuChE-associated AAA activity.
Serotonin and related amines were very weak on BuChE-associated AAA
activity. These results indicate that the inhibitory potencies of the
active site anti-ChE agents on the AAA activity associated with eel AChE
and horse serum BuChE are closely correlated with their action on the
respective ChE. In addition, the efficacy of tacrine, E2020,
heptyl-physostigmine and (+/-)-huperzine A in the treatment of
Alzheimer\'s disease is unlikely to be related to the action of these
drugs on ChE-associated AAA.

500\. Coyle, J. and P. Kershaw, *Galantamine, a cholinesterase inhibitor
that allosterically modulates nicotinic receptors: effects on the course
of Alzheimer\'s disease.* Biol Psychiatry, 2001. 49(3): p. 289-99.
Despite the proven efficacy of acetylcholinesterase inhibitors in
Alzheimer\'s disease, there is a need for new and more effective
treatments. Galantamine is a novel treatment for Alzheimer\'s disease
that inhibits acetylcholinesterase and modulates nicotinic receptors. In
randomized, double-blind, placebo-controlled studies of up to 6 months
duration, galantamine significantly improved cognitive function.
Galantamine also had beneficial effects on instrumental and basic
activities of daily living, and postponed the progression of behavioral
symptoms. Patients who completed one of the 6-month, placebo-controlled
studies were eligible to enter a 6-month, open-extension study of the
24-mg/day dose of galantamine. At the end of 12 months, cognitive
function and activities of daily living were preserved in those patients
who had been treated throughout the study with galantamine 24 mg/day. At
12 months, this group of patients had significantly better cognitive
functions than patients who had been treated with a placebo for 6 months
before receiving galantamine. These studies indicate that galantamine
postpones the progression of symptoms in Alzheimer\'s disease. Since
galantamine shows the greatest benefits when treatment is started early,
its long-term benefits may result from an effect on the underlying
disease process; such an effect might be mediated by galantamine\'s
concomitant action on nicotinic receptors.

501\. Cummings, J.L., D.G. Gorman, and J. Shapira, *Physostigmine
ameliorates the delusions of Alzheimer\'s disease.* Biol Psychiatry,
1993. 33(7): p. 536-41. Alzheimer\'s disease (AD) patients frequently
manifest delusions, and the cholinergic deficiency of AD may contribute
to this aspect of the psychopathology of the disorder. In a
double-blind, crossover study involving two patients, we compared the
antidelusional efficacy of physostigmine, an acetylcholinesterase
inhibitor, with haloperidol, a widely used neuroleptic agent.
Physostigmine ameliorated the delusions and produced fewer side effects.
These preliminary observations suggest that the cholinergic deficiency
contributes to the occurrence of delusions in AD and cholinergic therapy
may have a role in the treatment of the delusional symptoms.

502\. Cummings, J.L., *et al.*, *Metrifonate treatment of the cognitive
deficits of Alzheimer\'s disease. Metrifonate Study Group.* Neurology,
1998. 50(5): p. 1214-21. The efficacy and safety of metrifonate, an
acetylcholinesterase inhibitor, was evaluated clinically in patients
diagnosed with mild to moderate Alzheimer\'s disease (AD). This was a
prospective, 30-week, multicenter, double-blind, randomized, parallel
group, dose-finding study, which included a 2-week screening period, a
12-week treatment period, and follow-up visits at 8 and 16 weeks
post-treatment. Patients received placebo or metrifonate once daily.
Metrifonate-treated patients received a loading dose of 0.5 mg/kg (25 to
45 mg), 0.9 mg/kg (45 to 80 mg), or 2.0 mg/kg (100 to 180 mg) for 2
weeks, followed by a maintenance dose of 0.2 mg/kg (10 to 20 mg), 0.3
mg/kg (15 to 25 mg), or 0.65 mg/kg (30 to 60 mg) for 10 weeks. Four
hundred eighty patients were enrolled. Percentages of patients
completing double-blind treatment were 96% in the placebo group and 89
to 94% in the metrifonate group. Metrifonate significantly improved
cognitive ability, as assessed by the Alzheimer\'s Disease Assessment
Scale-Cognitive Subscale (ADAS-Cog), and enhanced global function, as
assessed the Clinicians\'s Interview-Based Impression of Change with
Caregiver Input (CIBIC-Plus). At 3 months, in the intent-to-treat
patients, the treatment difference for the change in ADAS-Cog score in
favor of metrifonate was 2.94 points (95% CI, 1.61 to 4.27; p = 0.0001).
These patients also exhibited a 0.35-point improvement on the CIBIC-Plus
relative to the placebo patients (95% CI, 0.15 to 0.54; p = 0.0007).
Patients receiving lower drug doses had scores intermediate to those of
the placebo and the 0.65 mg/kg metrifonate groups on both performance
scales. The drug was well tolerated; side effects were predominantly
gastrointestinal in nature, and no hepatic toxicity was observed.
Therefore, in this study, metrifonate safely improved the cognitive
deficits and benefited the global function of AD patients.

503\. Cutler, N.R. and J.J. Sramek, *The target population in phase I
clinical trials of cholinergic compounds in Alzheimer disease: the role
of the \"bridging study\".* Alzheimer Dis Assoc Disord, 1995. 9(3): p.
139-45. Our experience with studies investigating central nervous system
active compounds in Alzheimer disease (AD) patients suggest that
conducting a \"bridging study,\" in which patients from the target
population are included in Phase I, could expedite the drug development
process in AD. With one acetylcholinesterase (AChE) inhibitor compound
(velnacrine), we found that AD patients tolerated considerably lower
dosages than young normals and healthy elderly subjects, whereas our
findings were exactly the opposite with another AChE inhibitor
(eptastigmine). In studies of a muscarinic agonist (CI-979), AD patients
were able to tolerate dosages higher than those that were well tolerated
in young normals. A possible explanation for differences in drug effect
and tolerance in the target population may be the pathologic changes in
both the brain and the peripheral nervous system that are associated
with AD.

504\. Cutler, N.R., *et al.*, *Safety and tolerability of metrifonate in
patients with Alzheimer\'s disease: results of a maximum tolerated dose
study.* Life Sci, 1998. 62(16): p. 1433-41. Metrifonate, a pro-drug that
is transformed non-enzymatically into a potent inhibitor of
acetylcholinesterase (AChE), has been used in the tropics for over 30
years for the treatment of schistosomiasis. A pilot study, and Phase I
and Phase II studies of metrifonate in Alzheimer\'s disease (AD)
patients conducted prior to the current study showed benign,
dose-dependent adverse event profiles consisting primarily of
gastrointestinal events, optimal daily dosing with a loading phase (in
the absence of a loading dose phase, 6-8 weeks were required to attain
steady-state AChE inhibition levels), and an improvement in Alzheimer\'s
Disease Assessment Scale (ADAS) scores. The current open-label study was
designed to evaluate the safety and tolerability of relatively high
loading doses, followed by lower maintenance doses of metrifonate in the
same patient population, and to determine the maximum tolerated dose
(MTD) of metrifonate. Accordingly, the first cohort of 8 probable AD
patients (per National Institute of Neurological and Communicative
Disorders and Stroke-Alzheimer\'s Disease and Related Disorders
Association \[NINCDS-ADRDA\] criteria) were administered once-daily
loading doses of 2.5 mg/kg (125-225 mg) for 14 days, followed by 4.0
mg/kg (200-360 mg) for an additional 3 days. These patients were
maintained on once-daily doses of 2.0 mg/kg (100-180 mg) for 14 days.
AChE inhibition for this cohort ranged from 88% to 94%. On Day 28 of 31,
this cohort was discontinued due to moderate to severe side effects in 6
patients; consequently, the second cohort of 8 probable AD patients
received a once-daily loading dose of 2.5 mg/kg (125-225 mg) for 14 days
followed by a once-daily maintenance dose of 1.5 mg/kg (75-135 mg) for
35 days. This maintenance dose yielded an AChE inhibition level ranging
from 89% to 91%. In spite of an AChE inhibition level comparable to that
achieved with the higher dose, the reduced dose was associated with a
more favorable adverse event profile which was mainly gastrointestinal
and musculoskeletal in nature. The maximum tolerated dose was
established at 1.5 mg/kg/day (75-135 mg/day) for maintenance dosing in
AD patients.

505\. Cutler, N.R., *et al.*, *Dose-dependent CSF acetylcholinesterase
inhibition by SDZ ENA 713 in Alzheimer\'s disease.* Acta Neurol Scand,
1998. 97(4): p. 244-50. INTRODUCTION: This study evaluates the activity
of SDZ ENA 713, a centrally-selective acetylcholinesterase (AChE)
inhibitor, in the cerebral spinal fluid (CSF) of patients with
Alzheimer\'s disease (AD), and its relationship to central and
peripheral pharmacokinetic parameters. METHODS: Eighteen AD patients
were enrolled in this open-label, multiple-dose study. Patients were
titrated in 1 mg bid/week increments to target doses of 1, 2, 3, 4, 5,
or 6 mg bid SDZ ENA 713. After patients had been maintained at their
target dose for at least 3 days, continuous CSF samples were obtained
via a lumbar catheter for 12.5 h, beginning 0.5 h prior to the final
dose of SDZ ENA 713. RESULTS: Dose-dependent inhibition of CSF AChE was
significantly correlated (P \< 0.05) with plasma drug and metabolite
concentrations. The 6 mg bid treatment group showed a maximum mean
inhibition of 62% at 5.6 h post-dose. CONCLUSION: Rapid, sustained,
dose-dependent inhibition of CSF AChE suggests that SDZ ENA 713 has
therapeutic potential in AD patients.

506\. Davidsson, P., *et al.*, *Differential increase in cerebrospinal
fluid-acetylcholinesterase after treatment with acetylcholinesterase
inhibitors in patients with Alzheimer\'s disease.* Neurosci Lett, 2001.
300(3): p. 157-60. The clinical significance and the effects of
pharmacological treatment of patients with Alzheimer\'s disease (AD)
were evaluated by measurement of acetylcholinesterase (AChE) in the
cerebrospinal fluid (CSF). CSF-AChE of AD patients was lower, not
significantly, compared with controls. However, CSF-AChE was
significantly increased after treatment of AD patients with AChE
inhibitors (donepezil and galantamine). The increase was higher in
patients treated with donezepil than in those treated with galantamine,
which might be related to different mechanisms for the substances. The
increase was also dose-dependent, and was especially marked in patients
showing a clinical response. These data suggest that CSF biomarkers are
capable not only of identifying a biochemical effect of drugs, but also
of differentiating between different compounds in a dose-dependent
manner.

507\. Davis, R.E., *et al.*, *Cholinergic therapies for Alzheimer\'s
disease. Palliative or disease altering?* Arzneimittelforschung, 1995.
45(3A): p. 425-31. Loss of cholinergic function in the neocortex and
hippocampus arising from death or atrophy of basal forebrain cholinergic
neurons is a consistent feature of the Alzheimer brain at autopsy or
biopsy. Replacement of lost cholinergic function, therefore, may be of
therapeutic benefit to the Alzheimer\'s (AD) patients. This can be
accomplished by enhancing endogenous levels of acetylcholine (ACh)
through inhibition of its degradation by acetylcholinesterase on by
directly mimicking its actions at postsynaptic muscarinic receptors.
Initial efforts focused on inhibition of cholinesterase activity with
tacrine (1,2,3,4-tetrahydroaminoacridine monochloride, CAS 1684-40-8,
THA, Cognex). Tacrine is a mixed, reversible inhibitor of cholinesterase
activity that binds near but not to the catalytically active serine in
the active site of the enzyme. Through this action tacrine indirectly
elevates ACh levels in the brains of animals and improves cognitive
performance in rodents and monkeys. More importantly, tacrine has been
shown to significantly improve several measures of cognitive performance
in probable AD patients in well-controlled clinical trials, although not
all patients respond to this agent. CI-979
((E)-1,2,5,6-tetrahydro-1-methyl-3-pyridine-carboxyaldehyde-O-meth yl
oxime, CAS 139886-04-7) is a non-subtype selective, partial muscarinic
agonist that enhances cognitive performance and increases central
cholinergic activity in rodents at doses below those required to
increase peripheral cholinergic tone. In normal healthy volunteers,
CI-979 is well tolerated at single and multiple doses (q 6 h) up to 1.0
mg. In normal healthy volunteers, CI-979 is well tolerated at single and
multiple doses (q 6 h) up to 1.0 mg. Expected signs of mild to moderate
peripheral cholinergic stimulation were noted at 0.5 to 1.0 mg doses (q
6 h).(ABSTRACT TRUNCATED AT 250 WORDS).

508\. Doody, R.S., *Clinical profile of donepezil in the treatment of
Alzheimer\'s disease.* Gerontology, 1999. 45 Suppl 1: p. 23-32. Although
the underlying pathogenesis of Alzheimer\'s disease (AD) is not fully
understood, one of its key features is the widespread loss of central
cholinergic innervation, known to be fundamental for cognitive
processes. This finding led to the hypothesis that pharmacological
enhancement of acetylcholine (ACh) neurotransmission may alleviate the
symptoms of AD. Currently, cholinergic therapy, particularly
cholinesterase (ChE) inhibition, represents the most realistic approach
to the symptomatic treatment of AD. Donepezil HCl, for example, is a
piperidine-based, reversible acetylcholinesterase (AChE) inhibitor,
chemically distinct from other ChE inhibitors and rationally designed
for the symptomatic treatment of AD. It is highly selective for
centrally acting AChE, with little or no affinity for
butyrylcholinesterase, present predominantly in the periphery. Phase I
and II clinical trials demonstrated donepezil\'s favourable
pharmacokinetic, pharmacodynamic and safety profile with no requirement
for dose modification in the elderly or in patients with renal or
hepatic impairment. Furthermore, its long half-life supports a simple
and convenient once-daily dosing regimen. Subsequent to encouraging
phase II clinical trial results, two pivotal, randomized, double-blind
phase III trials (of 15 and 30 weeks\' duration) demonstrated highly
significant improvements in cognition and global function in mild to
moderately severe AD patients treated with either 5 or 10 mg/day
donepezil compared with placebo. Adverse events in the phase II and III
trials, primarily cholinergic in nature, were transient and generally
mild in severity and resolved during continued donepezil administration.
Thus, the donepezil clinical trials programme has shown that this drug
is a clinically effective and well-tolerated, once-daily treatment for
the symptoms of mild to moderately severe AD.

509\. Doody, R.S., *et al.*, *Open-label, multicenter, phase 3 extension
study of the safety and efficacy of donepezil in patients with Alzheimer
disease.* Arch Neurol, 2001. 58(3): p. 427-33. BACKGROUND: Donepezil
hydrochloride is a selective acetylcholinesterase inhibitor approved for
the symptomatic treatment of mild to moderately severe Alzheimer disease
(AD). Controlled clinical trials of up to 24 weeks have demonstrated
that donepezil treatment (5 and 10 mg/d) significantly improves
cognition and global function. OBJECTIVE: To investigate the long-term
benefits of donepezil treatment in patients with AD. DESIGN:
Multicenter, open-label, 144-week extension of 2 US phase 3,
double-blind, placebo-controlled clinical trials: a 15-week study (12
weeks of treatment followed by a 3-week placebo washout) and a 30-week
study (24 weeks of treatment followed by a 6-week placebo washout).
INTERVENTIONS: All patients (N = 763) initially received donepezil, 5
mg/d, for 6 weeks, after which an increase to 10 mg/d was encouraged.
MEASURES: Primary efficacy measures were the Alzheimer\'s Disease
Assessment Scale-cognitive subscale and the Clinical Dementia Rating-Sum
of the Boxes. RESULTS: After the shorter 3-week placebo washout,
donepezil-associated benefits remained above original baseline values
for an additional 24 weeks of open-label treatment. Benefits on
Alzheimer\'s Disease Assessment Scale-cognitive subscale scores for
patients who received 10 mg/d in the double-blind study were evident
compared with the other groups for 108 weeks of open-label treatment. In
contrast, donepezil-associated benefits were lost after the 6-week
placebo washout, and scores decreased below original baseline values for
all patient groups. Although scores improved relative to the new
open-label study baseline scores after drug use was restarted, patients
remained below original baseline values. The most common adverse events
were associated with the nervous and digestive systems and were
generally mild and transient; 17% of patient discontinuations were
associated with adverse events. CONCLUSIONS: Donepezil is an effective
and safe drug for the long-term symptomatic treatment of mild to
moderately severe AD for up to 144 weeks (2.8 years), and sustained
treatment may confer some advantages.

510\. Dooley, M. and H.M. Lamb, *Donepezil: a review of its use in
Alzheimer\'s disease.* Drugs Aging, 2000. 16(3): p. 199-226. Donepezil
(E-2020) is a reversible, noncompetitive, piperidine-type cholinesterase
inhibitor. It is selective for acetylcholinesterase rather than
butyrylcholinesterase. Donepezil 5 and 10 mg/day significantly improved
cognition and global clinical function compared with placebo in well
designed short term trials (14 to 30 weeks) in 161 to 818 patients with
mild to moderate Alzheimer\'s disease. Beneficial effects on cognition
were observed from week 3 of treatment. Donepezil 10 mg/day
significantly delayed the deterioration in activities of daily living
(ADL) \[by 55 weeks\] compared with placebo in a retrospective analysis
of 1 trial, and in the largest trial significantly improved patients\'
abilities to perform complex tasks. However, no significant improvement
in function was observed with donepezil 5 mg/day in another trial. In
the 2 trials of longest duration donepezil (5 and 10 mg) significantly
delayed symptomatic progression of the disease. While there was no
evidence for a positive effect of donepezil on patients\' quality of
life, there are no validated measures of this parameter specific to
patients with Alzheimer\'s disease. Donepezil (5 and 10 mg)
significantly reduced caregiver burden. Long term efficacy data suggest
that improvements in cognition, global function or ADL are maintained
for about 21 to 81 weeks with donepezil (10 mg/day in most patients).
Donepezil is generally well tolerated with the majority of adverse
events being mild and transient. Predictably, most events were
cholinergic in nature and generally related to the gastrointestinal and
nervous systems. The incidence of these events was significantly higher
with donepezil 10 mg than with placebo in short term clinical trials;
however, this may have been due to the 7-day dose increase schedule used
in these studies and can be minimised by increasing the dose after a
longer (6-week) period. The incidence of serious adverse events was
generally similar between donepezil 5 and 10 mg (4 to 10%) and placebo
(5 to 9%) in short term trials. 26% of patients receiving donepezil (5
and 10 mg) reported serious events over a 98-week period in a long term
trial. Importantly, there was no evidence of hepatotoxicity with this
drug. Conclusions. Donepezil (5 and 10 mg) is an agent with a simple
once-daily dosage schedule which improves cognition and global clinical
function in the short (up to 24 weeks) and long term (up to about 1
year) in patients with mild to moderate Alzheimer\'s disease.
Improvements in ADL were also observed with donepezil 10 mg/day. Adverse
events associated with donepezil are mainly cholinergic. Donepezil has
been extensively studied and should be considered as a first-line
treatment in patients with mild to moderate Alzheimer\'s disease.

511\. Dubois, B., *et al.*, *A multicentre, randomized, double-blind,
placebo-controlled study to evaluate the efficacy, tolerability and
safety of two doses of metrifonate in patients with mild-to-moderate
Alzheimer\'s disease: the MALT study.* Int J Geriatr Psychiatry, 1999.
14(11): p. 973-82. BACKGROUND: Metrifonate is a long-lasting
acetylcholinesterase inhibitor being developed for the symptomatic
treatment of Alzheimer\'s disease (AD).OBJECTIVES: This study compared
the efficacy, tolerability and safety of two doses of metrifonate in
patients with mild-to-moderate AD, over a 26-week treatment period.
METHODS: Six hundred and five patients were randomized to placebo
(n=208), a 40/50 mg dose (40 or 50 mg by weight; n=200) or a 60/80 mg
dose (60 or 80 mg by weight; n=197) metrifonate. Patients randomized to
receive metrifonate were administered a once-daily loading dose of 80 or
120 mg based on weight for 2 weeks, followed by the relevant maintenance
dose for 24 weeks. Four main clinical domains of AD were assessed:
cognition (ADAS-cog and MMSE), psychiatric and behavioural symptoms
(ADAS-noncog and NPI), instrumental and basic activities of daily living
(DAD) and global functioning (CIBIC-plus, CIBIS-plus and GDS).RESULTS:
ADAS-cog performance was significantly improved in the 60/80 mg and
40/50 mg dose groups, compared with placebo, in the intention-to-treat
(ITT) population. In addition, statistically significant treatment
differences were demonstrated between the 60/80 mg dose group and
placebo on MMSE, ADAS-noncog, the NPI subitems of hallucinations and
apathy, DAD, CIBIC-plus, CIBIS-plus and the GDS. The performance of the
40/50 mg dose group was also significantly superior to placebo on the
CIBIS-plus and the NPI subitem aberrant motor behaviour. CONCLUSIONS:
Metrifonate significantly improved a wide range of symptoms across all
four clinical domains of AD in a dose-dependent manner, and was safe and
well tolerated at both doses studied.

512\. Ebmeier, K.P., *et al.*, *Effects of a single dose of the
acetylcholinesterase inhibitor velnacrine on recognition memory and
regional cerebral blood flow in Alzheimer\'s disease.*
Psychopharmacology (Berl), 1992. 108(1-2): p. 103-9. The effects of a
single oral dose of the acetylcholinesterase inhibitor velnacrine
maleate on word and object recognition memory and regional uptake of
99mTc-exametazime were examined in patients with Alzheimer\'s disease.
Word recognition memory was marginally improved 2 h after 75 mg
velnacrine. With the same dose of velnacrine a relative increase in
superior frontal uptake of 99mTc-exametazime was shown with single
photon emission computed tomography (SPECT). This suggests increased
regional perfusion and metabolism as a consequence of cholinergic
stimulation. The effect did not co-vary with the degree of memory
improvement, but, instead, more cognitively impaired patients showed a
greater increase in tracer uptake after velnacrine, suggesting
cholinergic hypersensitivity in the brains of Alzheimer patients.

513\. Emre, M., *Switching cholinesterase inhibitors in patients with
Alzheimer\'s disease.* Int J Clin Pract Suppl, 2002(127): p. 64-72.
Despite recognition that cholinesterase inhibitors can provide clinical
benefits for patients with Alzheimer\'s disease (AD), the average
durations of treatment and beneficial effects are not optimal in all
cases. This may be due to disappointing efficacy or poor tolerability of
the initial treatment, as well as secondary efficacy failure or adverse
effects emerging during the maintenance phase. In such cases,
pharmacological differences between available cholinesterase inhibitors
provide a good rationale to switch to another drug in the same class.
The pharmacological properties of rivastigmine, a dual inhibitor of
acetylcholinesterase (AChE) and butyrylcholinesterase, and donepezil and
galantamine, two AChE-selective inhibitors, are reviewed. Rivastigmine
is reported to show brain- and brain region-selectivity. Donepezil
appeared to be more selective for central than peripheral enzymes in
rats. Galantamine and donepezil have also been shown to exert nicotinic
receptor allosteric modulation in vitro, while rivastigmine has been
shown to increase binding of acetylcholine to nicotinic receptors in the
AD brain. Donepezil and galantamine are metabolised by the hepatic
CYP450 system, whereas rivastigmine is metabolised by its target
enzymes. Several switching studies indicated that a substantial
proportion of patients who fail to benefit from treatment with donepezil
could draw benefits after being switched to rivastigmine. An immediate
switch from donepezil to rivastigmine was reported to be well tolerated
and was not associated with cholinergic side effects. A post hoc
analysis of a 5-month trial with galantamine showed that patients had
similar efficacy outcomes, whether or not they had received prior
anticholinesterase therapy, suggesting that a previous failure to
respond to another cholinesterase inhibitor did not predict response to
galantamine. On the basis of available data it is suggested that
patients not tolerating or not responding to one particular
cholinesterase inhibitor may still draw benefits upon switching to
another.

514\. Farlow, M.R., *Pharmacokinetic profiles of current therapies for
Alzheimer\'s disease: implications for switching to galantamine.* Clin
Ther, 2001. 23 Suppl A: p. A13-24. Although no pharmacologic treatments
have been proved to alter the pathology of Alzheimer\'s disease,
acetylcholinesterase inhibitor (AChEI) therapy offers symptomatic
improvements in or delays in the progression of cognitive, behavioral,
and functional deficits. Tacrine, donepezil, rivastigmine, and
galantamine are the best studied agents in this class. These drugs have
varying pharmacokinetic, safety, and tolerability profiles that can
affect patient outcomes. Specifically, certain metabolic parameters (ie,
half-life and route of metabolism/elimination) can affect a drug\'s
tolerability and become important when a switch from one agent to
another is contemplated. The mechanism of action of galantamine, the
most recently approved AChEI. varies from that of the other AChEIs in
that it has allosteric modulating activity at nicotinic receptors in
addition to its ability to inhibit acetylcholinesterase. Benefits of
this dual mode of action on the effects of the disease have been
suggested.

515\. Farlow, M.R., *Do cholinesterase inhibitors slow progression of
Alzheimer\'s disease?* Int J Clin Pract Suppl, 2002(127): p. 37-44. In
the absence of a cure for Alzheimer\'s disease (AD), treatment has
focused on therapy to provide symptomatic benefits and to slow
progression of the disease, so that patients can maintain their
independence for as long as possible. New research suggests that
rivastigmine, a potent, pseudo-irreversible inhibitor of both
acetylcholinesterase (AChE) and butyrylcholinesterase that shows
preferential selectivity for the G1 form of AChE, may provide
symptomatic and disease progression slowing effects. The drug\'s
pharmacological properties may help to slow the conversion of diffuse,
benign amyloid plaques to neuritic plaques associated with clinical
dementia. In \'delayed-start\' paradigms\--open-label extensions of
placebo-controlled studies involving mild to moderate AD patients\--the
treatment effects of rivastigmine on cognitive and non-cognitive
outcomes at 52 weeks were even greater than those observed at 26 weeks,
and patients who received rivastigmine for the entire 52 weeks had
better outcomes than those who received rivastigmine only for the latter
26 weeks (having received placebo for the first 26 weeks during the
placebo-controlled phase). These treatment effects were even more robust
in patients with moderately severe disease, indicating that the
sustained long-term benefits of rivastigmine apply across the continuum
of disease severity. The results seen in those patients with mild and
moderately severe AD suggest that the progression of AD was being slowed
in treated patients and that a disease-modifying effect may have been
taking place. The effects of rivastigmine on cognition remain clinically
relevant for at least 2 years, with benefits over projected placebo
increasing over time. The long-term benefits of rivastigmine have also
been reported in behavioural domains of patients with mild to moderate
AD for 104 weeks and in patients with the Lewy body variant of AD for 96
weeks. Rivastigmine may slow AD progression, allowing patients to
maintain autonomy for longer.

516\. Ferris, S.H., *Switching previous therapies for Alzheimer\'s
disease to galantamine.* Clin Ther, 2001. 23 Suppl A: p. A3-7.
Acetylcholinesterase inhibitors (AChEIs) are the most frequently
prescribed drugs for the treatment of Alzheimer\'s disease (AD). To
date, donepezil is prescribed most often, but newer AChEIs have become
available. Rivastigmine entered the pharmaceutics market for AD in 2000,
and galantamine was approved for use in the United States in February
2001. Some patients with AD may already be taking a cholinesterase
inhibitor, but they or their caregivers may want to change therapies for
various reasons, such as lack of efficacy or poor tolerability.
Therefore, defined protocols for discontinuing one therapy and
initiating another therapy (ie, \"switching\") while maintaining
efficacy and minimizing cholinergic toxicity will be essential. A
post-hoc analysis of a clinical trial that enrolled patients with and
without previous exposure to AChEIs indicated that the efficacy and
tolerability of a second and different cholinesterase treatment were
similar in both subpopulations of patients. These findings suggest that
discontinuation of prior AChEI treatment is not predictive of future
poor response to an effective treatment.

517\. Fink, D.M., *et al.*, *Synthesis and evaluation of
5-amino-5,6,7,8-tetrahydroquinolinones as potential agents for the
treatment of Alzheimer\'s disease.* J Med Chem, 1995. 38(18): p.
3645-51. A series of 5-amino-5,6,7,8-tetrahydroquinolinones was designed
and synthesized as acetylcholinesterase inhibitors. The compounds are
related to hyperzine A, a naturally occurring cholinesterase inhibitor.
They inhibit acetylcholinesterase in vitro, and many are active in vivo
in reversing a scopolamine-induced impairment of 24 h memory in a
passive avoidance paradigm. Although these compounds were designed as
partial structures of huperzine A, it is unlikely that they bind to the
enzyme in a similar fashion, since they lack the unsaturated
three-carbon bridge of huperzine A and both the quinolinone nitrogen and
the amino group must be substituted in order to obtain good enzyme
affinity.

518\. Forette, F., R. Anand, and G. Gharabawi, *A phase II study in
patients with Alzheimer\'s disease to assess the preliminary efficacy
and maximum tolerated dose of rivastigmine (Exelon).* Eur J Neurol,
1999. 6(4): p. 423-9. Rivastigmine is a carbamate acetylcholinesterase
(AChE) inhibitor with central selectivity. Early studies showed that
daily doses up to 6 mg/day have some efficacy in patients with dementia
of the Alzheimer type (DAT). The present study was designed to assess
the safety, tolerability and efficacy of rivastigmine at doses up to 12
mg/day. A total of 114 patients with mild-moderate DAT were randomly
assigned to either rivastigmine (b.i.d. (twice daily) or t.i.d. (three
times daily)) or placebo in a double-blind fashion titrated to their
maximum tolerated dose over 10 weeks followed by an eight-week
maintenance phase. The mean maximum tolerated dose was approximately 10
mg/day (b.i.d. or t.i.d.). Gastrointestinal complaints, the majority of
which were mild to moderate, were the most frequently reported adverse
events. No clinically relevant changes in vital signs, haematology or
organ function were detected. Significantly more patients taking
rivastigmine b.i.d. were considered improved according to the
Clinicians\' Interview-Based Impression of Change-Plus (CIBIC-Plus) vs.
placebo (57% vs. 16%, respectively; P = 0.027). The Nurses\' Observation
Scale for Geriatric Patients (NOSGER) (memory component) and the
Alzheimer\'s Disease Assessment Scale-cognitive subscale (ADAS-cog) also
improved in the rivastigmine b.i.d. group vs. placebo (mean change from
baseline on NOSGER = -0.7 vs. +1.3, respectively; P = 0.037: mean change
from baseline on ADAS-cog = -2.7 vs. +0.2, respectively; P = 0.054).
Despite the relatively small size and limited duration of the study, the
finding that rivastigmine induced changes in the same (positive)
direction in all three dimensions measured suggests that rivastigmine at
doses of up to 12 mg/day has useful efficacy in patients with
mild-moderate DAT. Reports from larger phase III studies confirm this
finding. The results of this study also suggest that b.i.d. is the more
efficacious regimen and has comparable tolerability to the t.i.d.
regimen. Copyright Lippincott Williams & Wilkins.

519\. Fuschillo, C., *et al.*, *Cognitive deficits in Alzheimer\'s
disease: Treatment with acetylcholinesterase inhibitor agents.* Arch
Gerontol Geriatr, 2001. 33 Suppl 1: p. 151-158. .

520\. Garfield, F.B., *et al.*, *Assessment of Health Economics in
Alzheimer\'s Disease (AHEAD): Treatment with Galantamine in Sweden.*
Pharmacoeconomics, 2002. 20(9): p. 629-37. BACKGROUND: Like other
developed countries with aging populations, Sweden is expecting large
increases in the prevalence of Alzheimer\'s disease and corresponding
escalations in the cost of care for patients with this disease.
Galantamine, a new acetylcholinesterase inhibitor and nicotinic
modulator, has proved effective in managing patients with Alzheimer\'s
disease in clinical trials. OBJECTIVE: To estimate the long-term health
and economic impact of galantamine from the perspective of the public
health payer in Sweden. DESIGN AND SETTING: The Assessment of Health
Economics in Alzheimer\'s Disease (AHEAD) model compares galantamine
treatment with no pharmacologic treatment. It consists of a module based
on trial data followed by a projection module that uses the trial
results to predict the time until patients require full-time care (FTC)
or until their death. Forecasts were made for up to 10 years. The model
was customised to Sweden by using Swedish resource use profiles obtained
from the literature. RESULTS: Galantamine is predicted to reduce the
time patients require FTC by almost 10%. Approximately 5.6 patients with
mild-to-moderate disease would need to be treated to avoid one year of
FTC. This would result in savings averaging 27 436 Swedish kronas (SEK)
\[3131 euros (EUR)\] per patient over 10 years (1998 values). To avoid
one year of FTC, 3.9 patients with moderate disease would need to be
treated, with savings averaging SEK49 019 (EUR5594) per patient over
10.5 years. Sensitivity analyses of key parameters, such as proportion
of patients needing FTC treated in the community, cost of care in an
institution, cost of FTC care in the community, the price of
galantamine, and the discount rate, found savings with galantamine would
occur under most circumstances. CONCLUSION: Galantamine can increase the
time before patients require FTC, and may also lead to savings as
treatment costs are offset by reductions in other healthcare
expenditures and the costs associated with FTC.

521\. Geib, S.J., W. Tuckmantel, and A.P. Kozikowski, *Huperzine A\--a
potent acetylcholinesterase inhibitor of use in the treatment of
Alzheimer\'s disease.* Acta Crystallogr C, 1991. 47 ( Pt 4): p. 824-7.
Huperzine A, 9-amino-13-ethylidene-11-methyl-4-azatricyclo
\[7.3.1.0(3,8)\]trideca-3(8),6,11-trien-5-one, C15H18N2O, Mr = 242.32,
monoclinic, P2(1)/n, a = 8.8574 (6), b = 12.1833 (7), c = 12.4278 (7) A,
beta = 99.956 (5) degrees, V = 1320.9 (1) A3, Z = 4, Dx = 1.22 g cm-3,
lambda(Cu K alpha) = 1.54178 A, mu = 5.75 cm-1, F(000) = 520, T = 296 K,
RF = 6.30% for 1402 reflections with Fo greater than or equal to 5
sigma(Fo) and 183 parameters. The pyridone ring is planar and the
stereochemistry of the C(11)\--C(12) double bond is E.

522\. Gelinas, I., S. Gauthier, and P.A. Cyrus, *Metrifonate enhances
the ability of Alzheimer\'s disease patients to initiate, organize, and
execute instrumental and basic activities of daily living.* J Geriatr
Psychiatry Neurol, 2000. 13(1): p. 9-16. The objective of this analysis
was to evaluate comprehensively the efficacy of metrifonate, a
long-acting acetylcholinesterase inhibitor, in improving the ability of
mild-to-moderate Alzheimer\'s disease (AD) patients to perform
activities of daily living (ADLs). Alzheimer\'s disease patients with
Mini-Mental State Examination scores of 10 to 26 were enrolled in three
26-week trials to receive once-daily placebo (n = 430) or metrifonate 30
to 60 mg (by weight, n = 650) or 60/80 mg (by weight, n = 197).
Metrifonate efficacy was assessed using the Disability Assessment for
Dementia scale. Data from the three studies were pooled and analyzed
retrospectively. The intent-to-treat analysis (last observation carried
forward) at 26 weeks demonstrated that metrifonate significantly
improved the ability of AD patients to perform ADLs when compared with
placebo (30-60 mg dose, delta = 3.03; P = .002; 60/80 mg dose, delta =
5.25; P = .0002). Metrifonate significantly improved the ability of the
AD patients to perform instrumental ADLs, those abilities typically lost
first during the disease process (30-60 mg dose, delta = 3.88, P = .002;
60/80 mg dose, delta = 5.79, P = .003). Metrifonate also tended to
improve, relative to placebo, the ability of AD patients to use three
levels of executive skills when performing ADLs: initiation (30-60 mg
dose, delta = 3.45, P = .001; 60/80 mg dose, delta = 5.44, P = .003),
planning/organization (30-60 mg dose, delta = 4.50, P = .004; 60/80 mg
dose, delta = 4.89, P = .014), and effective execution (30-60 mg dose,
delta = 1.80, P = .076; 60/80 mg dose, delta = 4.06, P = .030). These
results indicate that metrifonate has a beneficial effect on the ADLs in
mild-to-moderate AD patients.

523\. Giacobini, E., *Selective inhibitors of butyrylcholinesterase: a
valid alternative for therapy of Alzheimer\'s disease?* Drugs Aging,
2001. 18(12): p. 891-8. The brain of mammals contains two major forms of
cholinesterases (ChEs): acetylcholinesterase (AChE) and
butyrylcholinesterase (BuChE). The two forms differ genetically,
structurally and in their kinetics. Butyrylcholine is not a
physiological substrate in mammalian brains which makes the function of
BuChE difficult to interpret. In human brains, BuChE is found in neurons
and glial cells as well as in neuritic plaques and tangles in patients
with Alzheimer\'s disease (AD).While AChE activity decreases
progressively in the brain of patients with AD, BuChE activity shows
some increase. In order to study the function of BuChE, we perfused
intracortically the rat brain with a selective BuChE inhibitor. We found
that extracellular acetylcholine levels increased 15-fold from 5 nmol/L
to 75 nmol/L concentrations, with little cholinergic adverse effect in
the animal. Based on these data, we postulated that two pools of ChEs
may be present in the brain: one mainly neuronal and AChE dependent; and
one mainly glial and BuChE dependent. The two pools show different
kinetic properties with regard to regulation of acetylcholine
concentration in the brain and can be separated with selective
inhibitors. The recent development of highly selective BuChE inhibitors
will allow us to test these new agents in patients with AD in order to
find out whether or not they represent an advantage for the treatment of
patients with AD as compared with selective (donepezil) or relatively
non-selective (rivastigmine, galantamine) ChE inhibitors presently in
use. The association between a BuChE-K variant and AD has not been
confirmed in several studies. In conclusion, additional experimental and
clinical work is necessary in order to elucidate the role of BuChE in
normal brain function and in the brains of patients with AD. In the
future, it may be possible that selective BuChE inhibitors will have a
role in treatment of patients with advanced AD.

524\. Giacobini, E., *et al.*, *Inhibition of acetyl- and
butyryl-cholinesterase in the cerebrospinal fluid of patients with
Alzheimer\'s disease by rivastigmine: correlation with cognitive
benefit.* J Neural Transm, 2002. 109(7-8): p. 1053-65. SUMMARY:
Cholinesterase (ChE) inhibition represents the most efficacious
treatment approach for Alzheimer\'s disease (AD) to date. This
multiple-dose study has examined the relationship between inhibition of
acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities
in the cerebrospinal fluid (CSF) and cognitive change (measured by the
Computerised Neuropsychological Test Battery \[CNTB\]) following
administration of the ChE inhibitor, rivastigmine (Exelon((R))). In 18
patients with mild to moderate AD, CNTB scores, activities of AChE and
BuChE in the CSF, and plasma BuChE activity were determined prior to
treatment with rivastigmine. Doses of rivastigmine were then titrated (1
mg b.i.d./week) to final doses of 1, 2, 3, 4, 5 or 6 mg b.i.d. (n = 3
per dose). Following treatment with the target dose of rivastigmine for
at least 3 days, CNTB scores were re-determined. CSF samples were
continuously collected together with plasma samples prior to and for 12
hours after the final dose of rivastigmine, and AChE and BuChE
activities determined.AChE in CSF and BuChE in plasma were
dose-dependently inhibited by rivastigmine treatment. The inhibition of
BuChE in CSF was not clearly dose-dependent. A statistically significant
correlation was observed between the change in CNTB summary score and
inhibition of AChE activity (r = -0.56, p \< 0.05) and BuChE activity (r
= -0.65, p \< 0.01) in CSF. Improvement in speed-, attention- and
memory-related subtests of the CNTB correlated significantly with
inhibition of BuChE but not AChE activity in CSF. Weak or absent
correlation with change in cognitive performance was noted for
inhibition of plasma BuChE. These results indicate that cognitive
improvement with rivastigmine in AD is associated with central
inhibition of ChEs and support a role for central BuChE in addition to
AChE inhibition in modulating cholinergic function in AD.

525\. Giubilei, F., *et al.*, *Cardiac autonomic dysfunction in patients
with Alzheimer disease: possible pathogenetic mechanisms.* Alzheimer Dis
Assoc Disord, 1998. 12(4): p. 356-61. We studied a possible correlation
between autonomic cardiac activity and the level of the red blood cell
acetylcholinesterase (AChE) in patients with probable Alzheimer disease
(AD). The influence of cholinesterase inhibitor treatment on this
autonomic activity was evaluated. Twelve patients satisfying the
NINCDS-ADRDA criteria of probable AD and 10 healthy controls were
studied. Autonomic cardiac activity was evaluated by means of power
spectral analysis (PSA) of heart rate variability (HRV) using an
autoregressive algorithm on 250 consecutive electrocardiographic R-R
intervals. All patients received oral eptastigmine, a new cholinesterase
inhibitor, for 1 month. Before treatment, a simultaneous recording of
the electrocardiographic and respiratory activities was performed at
rest and subsequently during head-up tilt test at 700. Recording was
repeated on the last day of treatment. The level of AChE activity during
each recording was also evaluated. Spectrum power was calculated in
three main frequency bands: high frequency (HF), 0.15-0.4 Hz; low
frequency (LF), 0.04-0.15 Hz; very low frequency (VLF), \<0.04 Hz. In
addition, we calculated the total spectrum power (TSP) and the LF/HF
ratio. The TSP and the absolute value of each spectral component were
significantly lower in AD patients than in controls. In contrast with
controls, AD patients did not show any significant change before
treatment in either the LF and HF components or in the LF/HF ratio
during the tilt test. However, the modification in the LF component,
induced by tilting, showed a significant correlation with the level of
AChE activity (p \< 0.03). During the tilt test, the treatment caused
changes in LF and HF components and in the LF/HF ratio similar to those
observed in controls. These results suggest that the presence of
autonomic cardiac dysfunction in AD patients might be due to a
cholinergic deficit in the peripheral autonomic nervous system. Some
aspects of this autonomic dysfunction can be normalized by
cholinesterase inhibitor treatment.

526\. Gobburu, J.V., *et al.*, *Pharmacokinetic-pharmacodynamic modeling
of rivastigmine, a cholinesterase inhibitor, in patients with
Alzheimer\'s disease.* J Clin Pharmacol, 2001. 41(10): p. 1082-90.
Rivastigmine is a cholinersterase inhibitor approved recently for the
treatment of Alzheimer\'s disease (AD). The objective of this study is
to characterize the pharmacokinetics-pharmacodynamics of rivastigmine in
patients with AD. Eighteen AD patients received doses ranging from 1 to
6 mg bid for about 11 weeks. Rivastigmine and its active (major)
metabolite (ZNS 114-666, also called NAP 226-90), plasma, and
cerebrospinal fluid (CSF) concentrations were determined together with
the AChE activity and computerized neuropsychological test battery
(CNTB) scores. Nonlinear mixed-effects modeling of pharmacokinetic and
pharmacodynamic data was conducted using NONMEM. Rivastigmine and its
metabolite exhibited dose-disproportional pharmacokinetics. The apparent
clearance and volume of distribution (plasma) of rivastigmine were
estimated to be 120 L/h and 236 L, respectively. The relative
bioavailability at the 6 mg dose was about 140%. The metabolite had a
clearance of about 100 L/h and a volume of distribution of 256 L. The
kinetics of the parent and metabolite in CSF showed an equilibration
half-life of about 0.2 and 0.5 hours, respectively. The metabolite
levels in CSF correlated very well with the acetylcholinesterase
inhibition, with a ZNS 114-666 concentration of about 5.4 microg/L
required for half-maximal inhibition of acetylcholinesterase activity.
No statistically significant correlation of the CNTB scores with enzyme
inhibition, parent or metabolite concentration (plasma/CSF), or
rivastigmine dose could be established. The PK-PD model presented in
this study can provide valuable information to optimize the drug
development of rivastigmine and other related compounds and also in
rationalizing dosing recommendations.

527\. Gottwald, M.D. and R.I. Rozanski, *Rivastigmine, a brain-region
selective acetylcholinesterase inhibitor for treating Alzheimer\'s
disease: review and current status.* Expert Opin Investig Drugs, 1999.
8(10): p. 1673-1682. Alzheimer\'s disease is, in part, characterised by
the loss of neurones in the basal forebrain cholinergic cells that
project to the cerebral cortex and hippocampus. These impairments have
correlated with the memory loss noted in dementia of the Alzheimer\'s
type. This \'cholinergic hypothesis\' has led to the rational design of
drugs to enhance or stimulate acetylcholine-mediated neurotransmission.
Early acetylcholinesterase inhibitors, such as tacrine and
physostigmine, are poorly tolerated and have a short duration of action.
Rivastigmine is a centrally-selective acetylcholinesterase inhibitor
with a relatively long duration of action and is a
\'pseudo-irreversible\' cholinesterase inhibitor due to slow
dissociation of a carbamoyl derivative from the esteratic site of
acetylcholinesterase. Preclinical studies confirmed the central
selectivity of the drug and its distribution into the cerebrospinal
fluid (CSF). Early studies demonstrated that rivastigmine improved
cognition and was relatively well-tolerated at moderate doses. Clinical
investigations of rivastigmine administered at doses of 6 - 12 mg/day
significantly improved cognition, as measured by the ADAS-Cog score, and
activities of daily living, as measured by the Progressive Deterioration
Scale. Significant global improvements were also noted as measured by
the Clinician\'s Interview Based Impression of Change that required the
use of caregiver information. The most frequent adverse effects noted in
clinical trials were consistent with peripheral cholinergic stimulation
and included nausea, vomiting, abdominal pain, dizziness and diarrhoea.
These effects were dose-related and minimised by slow dose-escalation
upon initiation of therapy. Rivastigmine undergoes minimal metabolism by
the cytochrome P450 system. As a result, it has few drug interactions.
The drug is currently marketed widely in over 60 countries worldwide. In
the United States, the drug received \'approvable\' status subsequent to
the NDA filing, and should be available later this year.

528\. Greig, N.H., *et al.*, *The experimental Alzheimer drug
phenserine: preclinical pharmacokinetics and pharmacodynamics.* Acta
Neurol Scand Suppl, 2000. 176: p. 74-84. Phenserine, a phenylcarbamate
of physostigmine, is a new potent and highly selective
acetylcholinesterase (AChE) inhibitor, with a \> 50-fold activity versus
butyrylcholinesterase (BChE), in clinical trials for the treatment of
Alzheimer\'s disease (AD). Compared to physostigmine and tacrine, it is
less toxic and robustly enhances cognition in animal models. To
determine the time-dependent effects of phenserine on cholinergic
function, AChE activity, brain and plasma drug levels and brain
extracellular acetylcholine (ACh) concentrations were measured in rats
before and after phenserine administration. Additionally, its maximum
tolerated dose, compared to physostigmine and tacrine, was determined.
Following i.v. dosing, brain drug levels were 10-fold higher than those
achieved in plasma, peaked within 5 min and rapidly declined with
half-lives of 8.5 and 12.6 min, respectively. In contrast, a high (\>
70%) and long-lasting inhibition of AChE was achieved (half-life \> 8.25
h). A comparison between the time-dependent plasma AChE inhibition
achieved after similar oral and i.v. doses provided an estimate of oral
bioavailability of 100%. Striatal, in vivo microdialysis in conscious,
freely-moving phenserine-treated rats demonstrated \> 3-fold rise in
brain ACh levels. Phenserine thus is rapidly absorbed and cleared from
the body, but produces a long-lasting stimulation of brain cholinergic
function at well tolerated doses and hence has superior properties as a
drug candidate for AD. It selectively inhibits AChE, minimizing
potential BChE side effects. Its long duration of action, coupled with
its short pharmacokinetic half-life, reduces dosing frequency, decreases
body drug exposure and minimizes the dependence of drug action on the
individual variations of drug metabolism commonly found in the elderly.

529\. Hasegawa, K., *How to cope with Alzheimer\'s disease?* Neurobiol
Aging, 1998. 19(1 Suppl): p. S107-8. Alzheimer\'s disease (AD) is the
most common causative brain disease of primary dementia in the elderly.
The incidence of AD rises exponentially with age. Many countries, where
the aging population is a national problem, have to face how to cope
with AD. The main strategies against AD include the estimation of the
exact size of the problem, the elucidation of etiology of AD, the
development of effective treatment, and the establishment of the caring
system for AD sufferers in the community. A recent fruit of the research
is the new cholinomimetic agent E2020 (Donepezil), which is a highly
selective acetylcholinesterase inhibitor. As a result of clinical
trials, statistically significant improvements were seen in cognitive
function of AD patients. However, E2020 is one of the neurotransmitter
substitution therapies and is not specifically linked to the etiological
treatment. We have to make efforts to establish a definitive therapy for
AD and this depends on basic research, such as the molecular biology of
AD. Many AD patients and their families expect fruitful result from this
symposium, which will be a big milestone for the research of AD toward
the 21st Century.

530\. Hollister, L. and N. Gruber, *Drug treatment of Alzheimer\'s
disease. Effects on caregiver burden and patient quality of life.* Drugs
Aging, 1996. 8(1): p. 47-55. Alzheimer\'s disease is a devastating
illness that will become more common as the population ages. Although
clinical diagnosis of the illness is not certain without histological
examination of the brain, and misdiagnosis may occur, broad working
criteria to help diagnose the likely presence of Alzheimer\'s disease
are available. Thoughtful clinical evaluation improves diagnostic
accuracy, and appropriately diagnosed patients are critical for
involvement in research into new antidementia agents. Essential to the
discovery of new drugs is careful measurement of illness response. A
variety of scales\--some aimed at patients, others at their caregivers,
and yet others for clinicians\--assess Alzheimer\'s disease severity,
progression, symptom response, and quality of life. Of note, patient
response is not the only measurement of treatment benefit today. Growing
interest is also being placed on tracking the possible amelioration of
caregiver \'burden\'. This burden refers to the psychological, physical,
and material costs of providing care for an Alzheimer\'s patient over
long periods of time. A number of scales and questionnaires have been
developed and are occasionally used. Many drugs have been tried in
Alzheimer\'s disease, but very few have produced any benefit, and this
is often modest. Ergoloid mesylates, initially thought to be effective,
are now considered of little value. The cholinomimetic drugs, especially
the acetylcholinesterase inhibitor tacrine, have provided a very modest
benefit, slowing the progression of the illness for a number of months.
No cognitive improvement has been noted with the various nootropic
agents such as piracetam. Early studies with levacecarnine
(acetyl-L-carnitine), a substance that facilitates the use of fatty
acids, memantidine, the dimethyl derivative of amantidine, and the
calcium channel blocker nimodipine, have shown some promise, but require
larger, more rigorous studies. As mentioned above, documenting effects
in individual patients is crucial; examining for potential benefit to
caregivers is a growing part of research design. Current treatment
efforts will become more sophisticated as a deeper understanding of the
neurobiology of Alzheimer\'s disease develops. For the immediate future,
the goal is not cure but slowing of the disease process. Achieving this
limited goal would have a substantial impact on the financial and human
costs of the illness.

531\. Jane, F., *\[Pharmacological treatment of Alzheimer\'s disease:
present situation and perspectives\].* Rev Neurol, 1995. 23(119): p.
103-7. Alzheimer\'s disease (AD) is the commonest cause of dementia.
Although its ethology is unknown, there is increasing evidence in
support of the view that an abnormal degradation of the amyloid
precursor protein (APP), perhaps influenced by a number of genetic,
tisular or environmental factors, may be the primary cause of the many
biochemical and morphological disorders that exist in the associative
areas of the brain of these patients. Histopathologically it can be
shown by the presence of extracellular senile plaques, intraneuronal
fibrilar tangles and neuronal loss. There is no specific pharmacological
treatment at present to prevent the disease or its development, in spite
of the numerous and diverse drugs studied. Many of these studies are
methodologically inadequate. The attempt of activating the cholinergic
system has deserved special attention. A reversible inhibitor of
acetylcholinesterase, tacrine, has been approved in the United States
and other countries for the symptomatic treatment of mild to moderate
AD, but its use still arises many questions. Different drug and non drug
related interventions may be of great value in the care of these
patients, and may influence the specific pharmacological treatments. The
complexity and heterogeneity of AD and the multiple factors which may
take part in its evolution make it necessary to place special attention
on the methodological aspects of the clinical trials with new drugs for
the treatment of this disease.

532\. Jann, M.W., *Rivastigmine, a new-generation cholinesterase
inhibitor for the treatment of Alzheimer\'s disease.* Pharmacotherapy,
2000. 20(1): p. 1-12. Rivastigmine is a cholinesterase inhibitor (ChEI)
with a structural formula different from that of currently available
ChEIs. Tacrine and donepezil are classified as short-acting or
reversible agents since binding to acetylcholinesterase enzyme (AChE) is
hydrolyzed within minutes. Rivastigmine is classified as an
intermediate-acting or pseudo-irreversible agent due to its long
inhibition on AChE of up to 10 hours. Preclinical biochemical studies
indicated that rivastigmine has central nervous system selectivity over
peripheral inhibition. It ameliorated memory impairment in rats with
forebrain lesions. The drug is rapidly absorbed orally, with a
bioavailability of 0.355 and low protein binding (40%). Its elimination
half-life is less than 2 hours, and it is converted to an inactive
metabolite at the site of action, bypassing hepatic metabolic pathways.
Its disposition essentially is unaltered in patients with renal or
hepatic impairment. It also has dose-dependent effects on AChE
inhibition. In the two large multicenter clinical trials (total 1324
patients) that used a forced-dosage titration scheme, rivastigmine 6-12
mg/day was superior to placebo on three cognitive and functioning scales
(p\<0.001). Gastrointestinal symptoms are the most frequently reported
adverse events. They occurred mostly during the dosage titration phase
and decreased during the maintenance phase. Rivastigmine offers
clinicians another therapeutic agent to treat Alzheimer\'s disease.

533\. Johansson, M., E. Hellstrom-Lindahl, and A. Nordberg,
*Steady-state pharmacokinetics of tacrine in long-term treatment of
Alzheimer patients.* Dementia, 1996. 7(2): p. 111-7. The
pharmacokinetics of the cholinesterase inhibitor tacrine was studied in
5 Alzheimer patients during 12-31 months of treatment. A mean average
steady-state concentration in plasma ranging from 1.1 to 30 ng/ml was
obtained with doses ranging from 40 to 160 mg of tacrine daily. During
treatment with 80 mg daily a maximal plasma concentration of tacrine
(8.7 +/- 0.6 ng/ml) was obtained 1.3 +/- 0.2 h after intake of the
morning dose. The mean elimination half-life was estimated at 5-7 h and
remained unchanged when the tacrine dose was increased. The plasma
concentration of tacrine was stable during long-term treatment with
tacrine and no tolerance was observed regarding its cholinesterase
inhibitory effect. A maximal 40% inhibition of plasma cholinesterase
(ChE) activity and 60% inhibition of acetylcholinesterase activity in
red blood cells was measured following treatment with the highest dose
of 160 mg tacrine daily. A significant correlation was obtained between
the plasma concentration of tacrine and the inhibition of ChE activity
(p \< 0.001). The tacrine concentration in CSF was measured in each
patient on 1-3 occasions during the treatment and the ratio CSF/plasma
concentration was estimated to be 0.47 +/- 0.09 (n = 11).

534\. Kamal, M.A., *et al.*, *Kinetics of human acetylcholinesterase
inhibition by the novel experimental Alzheimer therapeutic agent,
tolserine.* Biochem Pharmacol, 2000. 60(4): p. 561-70. Characterization
of the kinetic parameters of tolserine, a novel acetylcholinesterase
(AChE) inhibitor of potential in the therapy of Alzheimer\'s disease, to
inhibit purified human erythrocyte AChE was undertaken for the first
time. An IC(50) value was estimated by three methods. Its mean value was
found to be 8.13 nM, whereas the IC(100) was observed to be 25.5 nM as
calculated by single graphical method. The Michaelis-Menten constant
(K(m)) for the hydrolysis of the substrate acetylthiocholine iodide was
found to be 0.08 mM. Dixon as well as Lineweaver-Burk plots and their
secondary replots indicated that the nature of the inhibition was of the
partial non-competitive type. The value of K(i) was estimated as 4.69 nM
by the primary and secondary replots of the Dixon as well as secondary
replots of the Lineweaver-Burk plot. Four new kinetic constants were
also investigated by polynomial regression analysis of the relationship
between the apparent K(i) (K(Iapp)) and substrate concentration, which
may open new avenues for the kinetic study of the inhibition of several
enzymes by a wide variety of inhibitors in vitro. Tolserine proved to be
a highly potent inhibitor of human AChE compared to its structural
analogues physostigmine and phenserine.

535\. Kaufer, D., *Beyond the cholinergic hypothesis: the effect of
metrifonate and other cholinesterase inhibitors on neuropsychiatric
symptoms in Alzheimer\'s disease.* Dement Geriatr Cogn Disord, 1998. 9
Suppl 2: p. 8-14. Preliminary studies suggest that non-cognitive
behavioural and personality alterations in Alzheimer\'s disease may
benefit from agents which inhibit central acetylcholinesterase (AChE). A
double-blind, placebo-controlled, 26-week study of the AChE inhibitor
metrifonate using the NeuroPsychiatric Inventory (NPI) to assess the
effects of treatment on neuropsychiatric symptoms observed statistically
significant mean change differences favouring treatment in the total NPI
score and in symptoms of depression, apathy and hallucinations, as well
as a nearly significant difference in aberrant motor behaviours. These
data are consistent with previous studies and are believed to represent
the first large prospective, controlled study demonstrating a beneficial
effect of AChE inhibitor therapy on neuropsychiatric symptoms in
Alzheimer\'s disease. The nature of non-cognitive symptom responses to
AChE inhibitor therapy and their potential impact on caregivers is
discussed.

536\. Kennedy, J.S., *et al.*, *Preferential cerebrospinal fluid
acetylcholinesterase inhibition by rivastigmine in humans.* J Clin
Psychopharmacol, 1999. 19(6): p. 513-21. This study sought to examine
the feasibility of prolonged assessment of acetylcholinesterase (AChE)
activity in the cerebrospinal fluid (CSF) of volunteers and to test the
hypothesis that rivastigmine (ENA-713; Exelon, Novartis Pharma AG,
Basel, Switzerland) selectively inhibits AChE in CSF in humans at a dose
producing minimal inhibition of the peripheral enzyme. Lumbar CSF
samples were collected continuously (0.1 mL x min(-1)) for 49 hours from
eight healthy volunteers who took either placebo or a single oral dose
of rivastigmine (3 mg). CSF specimens and samples of blood cells and
blood plasma were analyzed at intervals for rivastigmine and its
metabolite NAP 226-90 (\[-\] \[3-(\[1-dimethylaminolethyl)-phenol\]),
erythrocyte AChE activity, CSF AChE activity, and plasma and CSF
butyrylcholinesterase (BuChE) activity. Safety evaluations were
performed 23 hours after drug dosing and at the end of the study.
Evaluable data were obtained from six subjects. The mean time to maximal
rivastigmine plasma concentration (tmax) was 0.83 +/- 0.26 hours, the
mean maximal plasma concentration (Cmax) was 4.88 +/- 3.82 ng x mL(-1),
the mean plasma area under the concentration versus time curve
(AUC0-infinity) was 7.43 +/- 4.74 ng x hr x mL(-1), and the mean plasma
t1/2 was 0.85 +/- 0.115 hours. The concentration of rivastigmine in CSF
was lower than the quantification limit for assay (0.65 ng x mL(-1)),
but NAP 226-90 reached a mean Cmax of 3.14 +/- 0.57 ng x mL(-1). Only
minimal inhibition of erythrocyte AChE activity (approximately 3%) was
observed. Inhibition of AChE in the CSF after rivastigmine
administration was significantly greater than after placebo for up to
8.4 hours after the dose and was maximal (40%) at 2.4 hours. Plasma
BuChE activity was significantly lower after rivastigmine than after
placebo, but this was not clinically relevant. BuChE activity in CSF was
significantly lower after rivastigmine than after placebo for up to 3.6
hours after dosing, but this difference was not sustained. This study
confirms the feasibility of using continuous measurement of AChE
activity in CSF over prolonged periods, that rivastigmine markedly
inhibits CSF AChE after a single oral dose of 3 mg, and that the
inhibition of central AChE is substantially greater than that of
peripheral AChE or BuChE.

537\. Kosasa, T., *et al.*, *Inhibitory effect of orally administered
donepezil hydrochloride (E2020), a novel treatment for Alzheimer\'s
disease, on cholinesterase activity in rats.* Eur J Pharmacol, 2000.
389(2-3): p. 173-9. Donepezil hydrochloride
((+/-)-2-\[(1-benzylpiperidin-4-yl)methyl\]-5, 6-dimethoxy-indan-1-one
monohydrochloride: E2020: donepezil) is a potent and selective
acetylcholinesterase inhibitor developed for the treatment of
Alzheimer\'s disease. The present experiments were designed to compare
the inhibitory effects of orally administered donepezil and other
cholinesterase inhibitors, tacrine (9-amino-1,2, 3,4-tetrahydroacridine
hydrochloride),
(S)-N-ethyl-3-\[(1-dimethyl-amino)ethyl\]-N-methyl-phenylcarbamate
hydrogentartrate (ENA-713, rivastigmine) and
3-\[1-(phenylmethyl)-4-piperidinyl\]-1-(2,3,4,
5-tetrahydro-1H-1-benzazepin-8-yl)-1-propanone fumarate (TAK-147), on
the cholinesterase activity in the brain and plasma of rats. Moreover,
in order to validate the cholinesterase inhibition data, we measured the
brain and plasma concentrations of these drugs. Oral administration of
donepezil, tacrine, ENA-713 or TAK-147, caused a dose-dependent
inhibition of brain and plasma cholinesterase activities. The ID(50)
values of these compounds for brain cholinesterase activity were 6.3,
40.5, 7.2 and 26.8 micromol/kg, respectively. On the other hand, the
ID(50)170, 9.7 and 51.2 micromol/kg, respectively. Thus, the ratios of
the ID(50)4.2, 1.3 and 1.9, respectively. Brain and plasma
concentrations of donepezil, tacrine and TAK-147 increased
dose-dependently. The ratios of the concentrations (brain/plasma) of
these compounds were 6.1-8.4 for donepezil, 14.5-54.6 for tacrine and
7.0-20.6 for TAK-147. The values of 50% inhibitory concentration of
these drugs in the brain were 0.42, 3.5 and 1.1 nmol/g, respectively. In
contrast, the brain and plasma concentrations of ENA-713 at all doses,
except the two highest doses, were below the quantification limit. These
results suggest that orally administered donepezil satisfactorily
penetrates into the brain and inhibits cholinesterase there, and that
donepezil is a potent and selective inhibitor of brain cholinesterase in
comparison with plasma cholinesterase in vivo.

538\. Kuhl, D.E., *et al.*, *Limited donepezil inhibition of
acetylcholinesterase measured with positron emission tomography in
living Alzheimer cerebral cortex.* Ann Neurol, 2000. 48(3): p. 391-5.
Based on surrogate assays of peripheral red blood cells, reports state
that widely prescribed doses of donepezil hydrochloride provide nearly
complete inhibition of cerebral cortical acetylcholinesterase activity
in the treatment of Alzheimer\'s disease (AD). To test this, direct
positron emission tomography measures of cerebral acetylcholinesterase
activity were made in AD patients before and after treatment with
donepezil (5 and 10 mg/day) for at least 5 weeks and compared with
similar measures in normal controls who were untreated or after acute
administration of another AChE inhibitor, physostigmine salicylate (1.5
mg/hr). After physostigmine, acetylcholinesterase inhibition averaged
52% in normal cerebral cortex. After donepezil, cerebral cortical
inhibition in AD brain averaged only 27%. Clinical trials of this
donepezil dose schedule are not testing the effect of nearly complete
cerebral cortical inhibition.

539\. Lilienfeld, S., *Galantamine - a novel cholinergic drug with a
unique dual mode of action for the treatment of patients with
Alzheimer\'s disease.* CNS Drug Rev, 2002. 8(2): p. 159-76. Galantamine
hydrobromide is a tertiary alkaloid drug that has been developed and
approved in a number of countries including the USA and several
countries in Europe as a treatment for mild-to-moderate Alzheimer\'s
disease (AD). Galantamine has a unique, dual mode of action. It is a
reversible, competitive inhibitor of acetylcholinesterase (AChE), and is
the only drug actively marketed for the treatment of AD with proven
activity as an allosteric modulator of nicotinic acetylcholine receptors
(nAChRs). This latter activity is thought to be particularly important
since decreases in the expression and activity of nAChRs make a large
contribution to the reduction in central cholinergic neurotransmission
in patients with AD. Galantamine exhibits favorable pharmacokinetic
characteristics including predictable linear elimination kinetics at the
recommended maintenance doses (16 and 24 mg/day), a relatively short
half-life (approximately 7 h) and high bioavailability. It is
extensively metabolized in numerous pathways, mainly in the liver via
cytochrome P450 enzymes CYP2D6 and CYP3A4, and has a low potential for
clinically significant drug-drug interactions. During four large
randomized, double-blind, placebo-controlled trials of up to 6 months
duration, galantamine 16 and 24 mg/day significantly benefited cognitive
and global function, ability to perform activities of daily living (ADL)
and behavior, relative to placebo and baseline, for up to 6 months.
Caregiver burden (time spent by caregivers supervising patients or
assisting them with ADL), and caregiver distress (related to patients\'
behavioral symptoms) were also reduced. Cognitive and functional
abilities were preserved at or near baseline for at least 12 months in
patients who received galantamine 24 mg/day for 12 months in a long-term
US study. These benefits were maximized by early and continued
galantamine treatment and, again, were associated with significant
reductions in caregiver burden. Trials of the efficacy of galantamine in
dementia related to cerebrovascular disease have also yielded positive
results. There are no safety concerns associated with the use of
galantamine. The incidence of adverse events, particularly
cholinergically mediated events affecting the gastrointestinal system,
is generally low and can be minimized using the recommended slow
dose-escalation scheme. Galantamine may, therefore, help to reduce the
overall burden and cost involved in caring for dementia patients. Taking
all evidence into account, galantamine has the potential to become a
first-line therapy for dementia.

540\. Lopez-Pousa, S. and C. Lombardia Fernandez, *\[Treatment of
Alzheimer\'s disease: acetylcholinesterase inhibitors\].* Neurologia,
1999. 14(4): p. 180-8. AIM: The cognitive deficiency of Alzheimer\'s
disease is attributed to a dysfunction in the cerebral cholinergic
systems. Current drug treatments are directed at stimulating cholinergic
transmission. The aim of this study was to evaluate the latest
cholinergic drugs available an those about to appear in the market.
METHODS: A review of the most recent studies published regarding the
physiopathology of Alzheimer disease and the results following treatment
with donepezil, rivastigmine and metriphonate was carried out. RESULTS:
Donepezil is a specific, reversible acetylcholinesterase inhibitor of
close to 100% absorption and a half-life of 70 h, achieving stable
concentrations at approximately 3 weeks. Patients treated with a single
daily dosis of 5 or 10 mg improve in the ADAS-Cog scale. The medication
is initiated with a dosis of 5 mg/day. Rivastigmine is a competitive,
pseudoirreversible inhibitor with a half-life of 2 h, although it acts
for approximately 10 h. The Adas-Cog scale and the CIBIC-Plus improve in
patients treated with a daily dosis of 6 or 12 mg taken in two doses.
Administration should be initiated at low doses (3 mg/day) which are
progressively increased. Metriphonate is a prodrug of short life which
inhibits acetylcholinesterase through a metabolite (DDVP) with a
half-life in the circulation of 2 h. Improvement is observed in the
ADAS-Cog scale and the CIBIC-Plus and in behavior disorders at doses of
0.3 and 0.65 mg/kg/day. Doses between 30 and 60 mg/day are effective.
CONCLUSIONS: Different studies carried out with the acetylcholinesterase
inhibitors donepezil, rivastigmine and metriphonate have been effective
in the control of the cognitive symptoms of Alzheimer disease in the
initial or moderate phases of the disease.

541\. Mattio\*, T., *et al.*, *The effects of physostigmine on
acetylcholinesterase activity of CSF plasma and brain. A comparison of
intravenous and intraventricular administration in beagle dogs.*
Neuropharmacology, 1986. 25(10): p. 1167-77. The effects of various
doses of physostigmine (Phy) on the activity of acetylcholinesterase
(AChE) in plasma, cerebrospinal fluid (CSF) and brain were studied in
beagle dogs. Two routes of administration were compared: intravenous
(i.v.) and intracerebroventricular (i.c.v.). With
intracerebroventricular administration, over 90% inhibition of the
activity of AChE in CSF was reached within 5 min of injection at all
doses (10-120 micrograms). Even at the smallest dose (10 micrograms),
50% inhibition of activity of the enzyme in CSF was still present at 90
min. The activity of AChE in plasma was only minimally inhibited by
intraventricular administration of physostigmine. A different response
was obtained following intravenous administration of physostigmine
(250-1000 micrograms). The activity of AChE in plasma was inhibited but
the activity of AChE in CSF was increased (36-80% at 180 min). This
increase was dose-dependent and was blocked by pretreatment with
atropine (1.5 mg i.v.) which suggests the involvement of a muscarinic
receptor mechanism. The time course of the accumulation and regional
distribution of \[3H\]physostigmine in brain also varied with the route
of administration. At 5 min, with intravenous administration,
physostigmine (1000 micrograms) reached greater concentrations and
caused greater inhibition of AChE in the cortex. With intraventricular
administration, physostigmine (80 micrograms) reached greater
concentrations in two regions adjacent to the ventricular surface: the
striatum and hippocampus. These regions also showed greater inhibition
of the activity of AChE. Moderate to severe symptoms of cholinergic
hyperactivity were seen only with the largest intraventricular dose (120
micrograms). This study suggests that intraventricular administration of
physostigmine, a reversible inhibitor of cholinesterase (ChE), may offer
distinct advantages over intravenous administration. Inhibition of
acetylcholinesterase in CSF was more pronounced and persisted longer
when physostigmine was administered directly into the CSF than when
given intravenously. The implications of this study for a cholinergic
therapy of Alzheimer\'s disease are discussed.

542\. McKeith, I.G., *The clinical trial protocol of the Metrifonate in
Alzheimer\'s Trial (MALT).* Dement Geriatr Cogn Disord, 1998. 9 Suppl 2:
p. 2-7. The promising results of early trials in Alzheimer\'s disease
with the acetylcholinesterase inhibitor metrifonate prompted initiation
of the Metrifonate in ALzheimer\'s Trial (MALT). MALT is an
international, randomized, double-blind, placebo-controlled,
parallel-group study which was designed to determine, over a 26-week
period, the efficacy, tolerability and safety of two doses of
metrifonate in patients with probable Alzheimer\'s disease. A total of
605 patients were randomized to receive either a daily dose of oral
metrifonate 40/50 mg (n = 200, by body weight \<65 kg/\> or =65 kg) or
metrifonate 60/80 mg (n = 197, by body weight \<65 kg/\> or = 65 kg).
Patients were assessed in the key symptom domains of Alzheimer\'s
disease, i.e. cognition, behavioural and psychiatric disturbances,
activities of daily living and global function. In summary,
administration of metrifonate for 26 weeks to the intent-to-treat
population significantly benefited cognitive performance, global
function and certain aspects of behaviour and functional ability
compared with placebo. These efficacy results were associated with high
levels of acetylcholinesterase inhibition and a good safety and
tolerability profile. The protocol of MALT is discussed here. Full
results of the study will be available in a separate publication.

543\. McLendon, B.M. and P.M. Doraiswamy, *Defining meaningful change in
Alzheimer\'s disease trials: the donepezil experience.* J Geriatr
Psychiatry Neurol, 1999. 12(1): p. 39-48. Regulatory guidelines in the
US and Europe generally require that a drug specifically indicated for
treating Alzheimer\'s disease (AD) must demonstrate an effect upon the
core manifestations of dementia. Progressive cognitive and functional
losses are the cardinal features of AD. In the US, current guidelines
require that new AD treatments show effectiveness on performance-based
measures of cognition and on clinician-rated global assessments.
Improvement in function is also emphasized in the European guidelines.
The primary instruments that have been used to evaluate changes in
cognition and global function in most recent AD trials are the cognitive
subscale of the Alzheimer\'s Disease Assessment Scale and a version of
the Clinician\'s Interview Based Impression of Change, respectively. The
results from three pivotal trials investigating the acetylcholinesterase
inhibitor, donepezil, are used to demonstrate the way in which these
tools are used, how to interpret the data they provide, and to determine
their overall value in ascertaining efficacy in clinical practice.

544\. Minthon, L., L. Edvinsson, and L. Gustafson, *Tacrine treatment
modifies cerebrospinal fluid neuropeptide levels in Alzheimer\'s
disease.* Dementia, 1994. 5(6): p. 295-301. Biochemical and
histochemical studies have demonstrated a widespread deficit in the
activity of acetylcholinesterase (AChE) in the brains of patients with
Alzheimer\'s disease (DAT). Multiple disturbances in several transmitter
systems have been found. The most consistent neurochemical changes in
DAT are reductions in the cholinergic system. The major pharmacological
approach today in DAT is based on the cholinergic theory assuming that
acetylcholine has a major cortical impact on cognitive processes.
Tetrahydroaminoacridine (THA, tacrine) is a centrally active reversible
acetylcholinesterase inhibitor. A large number of trials have been
performed in patients with DAT. This article was to evaluate whether THA
treatment induced neuropeptide alteration in DAT before and after 1 year
on oral THA treatment.

545\. Misson, J. and M.J. Kendall, *Therapeutic advances: donepezil for
the treatment of Alzheimer\'s disease.* J Clin Pharm Ther, 1997. 22(4):
p. 251-5. Until recently, few drugs have been available for the
treatment of Alzheimer\'s disease. The first such drug to be launched in
the U.K. was the acetylcholinesterase inhibitor, donepezil. The limited
published data on donepezil shows only modest cognitive benefit in
patients with Alzheimer\'s disease. The cost of diagnosis and drug
treatment, the distressing nature of the disease and the limited
evidence available, pose difficult decisions for the introduction of new
drugs and the management of this condition.

546\. Molloy, D.W. and R.D. Cape, *Acute effects of oral pyridostigmine
on memory and cognitive function in SDAT.* Neurobiol Aging, 1989. 10(2):
p. 199-204. This study reports the effects of the anticholinesterase
pyridostigmine on cognitive function in 15 elderly patients with senile
dementia of the Alzheimer type (SDAT). Each patient was given placebo
and pyridostigime 60 mg orally four times over 26 hours, with a seven
day washout between, using a randomized double-blind cross-over design.
There was no significant improvement in cognitive function following
placebo or pyridostigmine. We did not perform any preliminary
dose-finding trials to find the optimum dose of pyridostigmine, but gave
the drug in a predetermined fixed dosage to each patient. We conclude
that with this dosage, pyridostigmine did not significantly improve
cognitive function more than placebo in this group of elderly patients.

547\. Morris, J.C., *et al.*, *Metrifonate benefits cognitive,
behavioral, and global function in patients with Alzheimer\'s disease.*
Neurology, 1998. 50(5): p. 1222-30. OBJECTIVE: To evaluate the efficacy
and safety of metrifonate, an acetylcholinesterase inhibitor, in
patients clinically diagnosed with probable Alzheimer\'s disease (AD) of
mild to moderate severity. METHODS: A prospective, 36-week, multicenter,
double-blind, randomized, parallel group study of metrifonate in
probable AD patients, including a 2-week screening period, a 26-week
double-blind treatment period, and a follow-up visit at 8 weeks
post-treatment. A total of 24 ambulatory clinics in the United States in
a variety of settings, including contract research organizations, public
health facilities, and universities. Patients met diagnostic criteria
for probable AD as defined by the work group of the National Institute
for Neurological and Communicative Diseases and Stroke and the
Alzheimer\'s Disease and Related Disorders Association. Patients had
Mini-Mental State Examination (MMSE) scores of 10 to 26 and Ischemic
Scores (Rosen Modification) of \<4. A total of 408 patients were
enrolled. Percentages of patients completing double-blind treatment were
88% and 79% in the placebo and metrifonate groups, respectively. Rates
of discontinuation due to adverse events were 4% in the placebo group
and 12% in the metrifonate group. Placebo or metrifonate was
administered once daily. Metrifonate-treated patients received a loading
dose of 100 to 180 mg based on weight (2.0 mg/kg) for 2 weeks, followed
by a maintenance dose of 30 to 60 mg based on weight (0.65 mg/kg) for 24
weeks. Primary efficacy variables were the Alzheimer\'s Disease
Assessment Scale-Cognitive Subscale (ADAS-Cog) and the Clinician\'s
Interview-Based Impression of Change with Caregiver Input (CIBIC-plus).
Secondary efficacy variables included the Neuropsychiatric Inventory
(NPI), the Disability Assessment in Dementia, the Global Deterioration
Scale (GDS), the ADAS-Noncognitive subscale (ADAS-Noncog), the MMSE, and
the Clinician\'s Interview-Based Impression of Severity with Caregiver
Input (CIBIS-plus). Outcome measures reflected changes from baseline at
week 26 for all variables. Safety was assessed with incidences of
premature termination, treatment-emergent events and mortality, and
routine safety evaluations. RESULTS: After 26 weeks of metrifonate
therapy, a 2.86-point treatment difference (p = 0.0001) was observed in
the ADAS-Cog scores of the intent-to-treat AD patients. The treatment
difference in the mean CIBIC-plus score at this time was 0.28 points (p
= 0.0071). At week 26, treatment differences also were observed in the
mean NPI total score (p = 0.0161). Analysis of the remaining secondary
efficacy variables showed treatment differences that favored metrifonate
but did not reach statistical significance. Metrifonate adverse events
were predominantly mild in intensity. No hepatotoxicity was observed.
CONCLUSIONS: Metrifonate was safe and well-tolerated. It enhanced not
only the cognitive and global function, but also the behavioral function
of patients diagnosed with mild to moderate AD. Therefore, metrifonate
appears to be useful in the symptomatic treatment of AD.

548\. Moss, D.E., *et al.*, *Methanesulfonyl fluoride (MSF): a
double-blind, placebo-controlled study of safety and efficacy in the
treatment of senile dementia of the Alzheimer type.* Alzheimer Dis Assoc
Disord, 1999. 13(1): p. 20-5. The purpose of the present study was to
evaluate methanesulfonyl fluoride (MSF), a very long-acting
CNS-selective acetylcholinesterase (AChE) inhibitor, as a palliative
treatment for senile dementia of the Alzheimer type (SDAT). In
experiment I, MSF (0.03-0.18 mg/kg) was administered orally to 10 normal
volunteers to measure toxicity and establish dose/response function in
erythrocyte AChE. MSF produced a dose-response function of %inhibition =
(40)(Log10\[MSF mg/kg\] + 51.7) with no toxicity at these doses.
Experiment II was a 16-week double-blind, placebo-controlled study of
the safety and efficacy of MSF in doses of up to 0.18 mg/kg given three
times per week in 5 men and 10 women (60-82 years), with Mini-Mental
State Examination (MMSE) scores of 9-24, who had SDAT. MSF produced a
mean of 89.5% inhibition of erythrocyte AChE in patients and improved
cognitive performance as measured by the MMSE, Alzheimer Disease
Assessment Scale-Cognitive Subscale (ADAS-COG), Global Deterioration
Scale, and the Clinical Interview Based Impression of Change (CIBIC).
Most of the improvement on the ADAS-COG was maintained 8 weeks after
ending MSF. No patients left the study because of drug-related adverse
events and there were no toxic effects. MSF may be a safe and effective
palliative treatment for SDAT and further clinical trials in larger
groups of patients are warranted.

549\. Nobili, F., *et al.*, *Brain perfusion follow-up in Alzheimer\'s
patients during treatment with acetylcholinesterase inhibitors.* J Nucl
Med, 2002. 43(8): p. 983-90. Transient cognitive and behavioral
stabilization of patients with Alzheimer\'s disease (AD) is the main
goal of long-term acetylcholinesterase inhibitor (AChEI) therapy, but
response to treatment is variable and, indeed, only some of the patients
are stabilized. This is usually assessed by means of clinical and
neuropsychologic scales, whereas functional neuroimaging could allow
objective evaluation of the topographic correlates of the effect of
therapy on brain functioning. The aim of this study was to evaluate
brain perfusion changes by SPECT in AD patients during chronic AChEI
therapy in relation to their cognitive evolution. METHODS: Forty-seven
consecutive outpatients with mild-to-moderate probable AD (as defined by
the National Institute of Neurological and Communicative Disorders and
Stroke-Alzheimer\'s Disease and Related Disorders Association and the
Diagnostic and Statistical Manual of Mental Disorders \[4th edition
criteria\] and a score of \> or =15 on the Mini-Mental State Examination
\[MMSE\]) were enrolled in 2 centers over a 1-y period and underwent
SPECT with 99mTc-hexamethylpropyleneamine oxime at the time of
enrollment (t(0)). All of them started AChEI therapy. Nine patients were
lost at follow-up, and drugs were withdrawn from 3 patients. Of the
remaining 35 patients, who received regular AChEI therapy (donepezil, 5
or 10 mg/d; rivastigmine, 6 or 9 mg/d) throughout the observation
period, only the 31 patients receiving donepezil were considered to
avoid the possible confounding effect of different drugs. The 31
patients completed the study and a second SPECT examination was
performed 15.0 +/- 3.0 mo later (t(1)). They were divided into
stabilized (17 patients) and nonstabilized (14 patients) subgroups on
the basis of the minimum expected annual rate of decline of the MMSE
score, derived from a meta-analysis of the literature. SPECT data were
analyzed by means of statistical parametric mapping. RESULTS: At
baseline, the stabilized and nonstabilized patients were comparable for
age, sex distribution, education, MMSE scores, memory impairment
(selective reminding test \[SRT\]), apolipoprotein E genotype, AChEI
dose regimen, and SPECT findings. The SRT scores decreased significantly
(P \< 0.01) in the nonstabilized subgroup but not in the stabilized
subgroup. No significant difference was found between the baseline and
repeated SPECT data in the stabilized subgroup. In contrast, in the
nonstabilized subgroup a significant perfusion reduction was found in
the frontal, temporal, and parietal superficial cortex and in the
occipital precuneus in the right hemisphere and in the frontal and
mesial temporal cortex in the left hemisphere. On repeated SPECT,
regional cerebral blood flow was significantly lower in a left frontal
region in the nonstabilized group than in the stabilized group.
CONCLUSION: The regional cerebral blood flow decreases in several
cortical regions in AD patients with cognitive deterioration despite
long-term AChEI therapy, similar to that observed in untreated patients,
whereas it remains stable in AD patients with stabilized cognitive
performance during therapy.

550\. Nordberg, A. and A.L. Svensson, *Cholinesterase inhibitors in the
treatment of Alzheimer\'s disease: a comparison of tolerability and
pharmacology.* Drug Saf, 1998. 19(6): p. 465-80. Cholinesterase
inhibitors are currently the most established treatment strategy in
Alzheimer\'s disease. The treatment effect appears mainly to be
symptomatic. Effects on progression of the disease following long term
treatment, and possible neuroprotective effects, have been investigated.
Delay until nursing home placement has been reported. Three
cholinesterase inhibitors, tacrine, donepezil and rivastigmine, are in
clinical use. Other cholinesterase inhibitors, such as galantamine
(galanthamine), metrifonate, physostigmine, eptastigmine, are currently
under clinical evaluation. So far the efficacy appears to be comparable
between the various cholinesterase inhibitors; treatment for up to 6
months has produced an improvement in Alzheimer\'s Disease Assessment
Scale \-- Cognitive Subscale score (ADAS-cog) of between 1.8 and 4.9 in
patients with Alzheimer\'s disease. Tacrine, donepezil, galantamine and
physostigmine are reversible inhibitors of acetylcholinesterase and
butyrylcholinesterase, while metrifonate is considered to be an
irreversible inhibitor and rivastigmine a pseudoirreversible inhibitor.
Tacrine and physostigmine have lower bioavailability, 17 to 37% and 3 to
8%, respectively, than the other cholinesterase inhibitors such as
rivastigmine, galantamine and donepezil (40 to 100%). The elimination
half-life is considerably longer for donepezil (70 to 80h) in comparison
to most of the other cholinesterase inhibitors (0.3 to 12h). Donepezil
is therefore administered once daily in comparison to rivastigmine which
is administered twice daily and tacrine which is administered 4 times
daily. Simultaneous food intake lowers the plasma concentration of
tacrine and reduces the adverse effects of rivastigmine. Drugs like
theophylline and cimetidine have been reported to change the
pharmacokinetics of tacrine and donepezil. In contrast, concomitant
medication with various drugs with rivastigmine does not seem to cause
any drug interactions in patients with Alzheimer\'s disease. Tacrine,
donepezil and galantamine are metabolised via the cytochrome P450 (CYP)
liver enzymes. Active metabolites are known for tacrine and galantamine.
Rivastigmine is not metabolised via CYP enzymes, but via esterases and
is excreted in the urine. Tacrine is associated with hepatotoxicity
while other cholinesterase inhibitors seem devoid this adverse effect.
Increased liver enzyme values have been observed in 49% of patients with
Alzheimer\'s disease treated with tacrine. Rechallenge with tacrine
reduces the incidence of elevated liver enzyme levels. Peripheral
cholinergic adverse effects are common for the cholinesterase
inhibitors, with an incidence ranging between 7 to 30%. For some
cholinesterase inhibitors, such as rivastigmine, the cholinergic adverse
effects such as nausea, vomiting, dizziness, diarrhoea and abdominal
pain can be reduced by slowing the rate of dose titration.

551\. Olin, J. and L. Schneider, *Galantamine for Alzheimer\'s disease.*
Cochrane Database Syst Rev, 2001(1): p. CD001747. BACKGROUND:
Galantamine (also called galanthamine, marketed as Reminyl (Janssen))
can be isolated from several plants, including daffodil bulbs, and now
synthesized. Galantamine is a specific, competitive, and reversible
acetylcholinesterase inhibitor. It is also an allosteric modulator at
nicotinic cholinergic receptor sites potentiating cholinergic nicotinic
neurotransmission. A small number of early studies showed mild cognitive
and global benefits for patients with Alzheimer\'s disease, and recently
several multicentre clinical trials have been published with positive
findings. Galantamine has received regulatory approval in Sweden, is
available in Austria, and awaits marketing approval in the United
States, Europe, and other countries. OBJECTIVES: The objective of this
review is to assess the clinical effects of galantamine in patients with
probable Alzheimer\'s disease, and to investigate potential moderators
of an effect. SEARCH STRATEGY: The Cochrane Dementia Group specialized
register of clinical trials was searched using the terms
\'galantamine,\' and \'galanthamine\' (15 February 2000) as was the
Cochrane Controlled Trials Register (2000, Issue 2). These terms were
also used to search the following databases: EMBASE, MEDLINE, PsychLit;
Combined Health Information Database, NRR (National Research Register),
ADEAR (Alzheimer\'s Disease Education and Referral Centre clinical
database, BIOMED (Biomedicine and Health), Glaxo-Wellcome Clinical
Trials Register, National Institutes of Health Clinical Trials
Databases, Current Controlled Trials, Dissertation Abstracts (mainly
North American dissertations) 1961-1994, Index to UK Theses (British
dissertations) 1970-1994. Published reviews were inspected for further
sources. Additional information was collected from an unpublished
investigational brochure for galantamine. SELECTION CRITERIA: Trials
selected were randomized, double-blind, parallel-group, and unconfounded
comparisons of galantamine with placebo for a treatment duration of
greater than 4 weeks in people with Alzheimer\'s disease. DATA
COLLECTION AND ANALYSIS: Data were extracted independently by the
reviewers and pooled where appropriate and possible. The pooled odds
ratios (95%CI) or the average differences (95%CI) were estimated.
Intention-to-treat and observed cases data were both reported, if the
data were available to be reported. -Outcomes of interest include the
Alzheimer\'s Disease Assessment Scale-cognitive subscale (ADAS-cog),
clinical global impression of change (CIBIC-plus or CGIC), Alzheimer\'s
Disease Cooperative Study/Activities of Daily Living (ADCS-ADL),
Disability Assessment for Dementia scale (DAD) and Neuropsychiatric
Inventory (NPI). - Potential moderating variables of a treatment effect
included trial duration and dose. MAIN RESULTS: Seven trials were
identified that met criteria for entry, with 6 being Phase II or III
industry-sponsored multicentre trials. One was of 12 weeks duration; one
of 5 months; one of 29 weeks; and the rest of 6 months duration. Trials
of 5 months or more were aggregated in the analyses as \'6 months\'.
Overall, galantamine showed significant treatment effects at daily doses
of 16-32 mg/d for trials of 3- to 6-months duration. For global ratings,
trials of 3 months duration with doses of 24-32mg/d (Odds Ratio (OR)
2.2; 95%CI 1.4 to 3.7) and 36mg/d (OR 3.3; 95%CI 1.2 to 9.3) were
statistically significant in favour of treatment. For trials of 6 months
duration (5-months to 29 weeks), only doses of 8mg/d failed to be
statistically significant (24mg: OR 2.0; 95%CI 1.5 to2.5; 32mg: OR 1.9;
95%CI 1.4 to 2.5). For cognitive function over 6 months duration: at a
24mg/d, improvements measured -3.5 points (k=3; 95%CI -4.3 to -2.8) on
weighted mean difference on the ADAS-Cog scale, and -4.0 points at
32mg/d (k=2; 95%CI -5.0 to -3.0). Both observed cases (WMD 3.8; 95%CI
0.3 to 7.3) and intention to treat analyses using the Disability
Assessment of Dementia gave statistically significant results in favour
of treatment for daily doses of 32mg for 6 months duration. The small
number of trials available for analysis, however, limited the power of
analyses to detect differences. Galantamine consistently failed to show
statistically significant treatment effects at doses of 8mg/day.
Galantamine\'s adverse effects appear similar to those of other
cholinesterase inhibitors, in that it tends to produce gastrointestinal
effects acutely and with dosage increases. Overall, people treated with
galantamine at doses of 24-32 mg/d were more likely to discontinue
participation in most trials than were people treated with lower doses
or placebo, but in the one trial with a slower rate of titration the
discontinuation rate was not significantly greater than placebo for the
16 mg/day dose. (ABSTRACT TRUNCATED).

552\. Nitsch, R.M., *et al.*, *The selective muscarinic M1 agonist
AF102B decreases levels of total Abeta in cerebrospinal fluid of
patients with Alzheimer\'s disease.* Ann Neurol, 2000. 48(6): p. 913-8.
beta-Amyloid (Abeta) deposits in diffuse and compact senile plaques in
the brain are one of the defining histopathological features of
Alzheimer\'s disease (AD). Preventing Abeta deposition is a goal of drug
therapy for AD, because excessive amounts of Abeta may be toxic to
neurons. In preclinical studies, activation of the muscarinic M1
receptor subtype inhibited Abeta secretion from cultured cells. To
determine whether a similar sequence occurs in human beings, we
administered the selective M1 agonist AF102B to 19 AD patients and
measured total Abeta (Abeta(total)) levels in cerebrospinal fluid (CSF)
before and during treatment. Abeta(total) levels in CSF decreased in 14
patients by 22%, increased in 3 patients, and were unchanged in 2
patients; the overall decrease in the group as a whole was statistically
significant. To test the specificity of the M1 effect, we also measured
the relative changes in Abeta(total) levels in CSF during treatments in
separate sets of AD patients with the acetylcholinesterase inhibitor
physostigmine or the anti-inflammatory drug hydroxychloroquine. CSF
Abeta(total) levels did not change significantly in the 9 AD patients in
the physostigmine protocol or in the 10 AD patients in the
hydroxychloroquine study. These data provide evidence that the
activation of M1 receptors reduces Abeta levels in the CSF of AD
patients. If this effect also occurs in brain, M1 agonists may have
long-term therapeutic benefits by lowering amyloid in AD.

553\. Olin, J. and L. Schneider, *Galantamine for Alzheimer\'s disease
(Cochrane Review).* Cochrane Database Syst Rev, 2002(3): p. CD001747.
BACKGROUND: Galantamine (also called galanthamine, marketed by Janssen
as Reminyl) was originally isolated from several plants, including
daffodil bulbs, but is now synthesized. Galantamine is a specific,
competitive, and reversible acetylcholinesterase inhibitor. It is also
an allosteric modulator at nicotinic cholinergic receptor sites
potentiating cholinergic nicotinic neurotransmission. A small number of
early studies showed mild cognitive and global benefits for patients
with Alzheimer\'s disease (AD), and recently several multicentre
clinical trials have been published with positive findings. Galantamine
has received regulatory approval in 29 counties: Argentina, Australia,
Canada, Czechia, the European Union (except for The Netherlands),
Iceland, Korea, Mexico, Norway, Poland, Singapore, South Africa,
Switzerland, Thailand, and the United States. OBJECTIVES: The objective
of this overview is to assess the clinical effects of galantamine in
patients with probable AD, and to investigate potential moderators of an
effect. SEARCH STRATEGY: The trials were identified from a search of the
Specialized Register of the Cochrane Dementia and Cognitive Improvement
Group on 15 May 2002 using the terms galantamine and Reminyl. Published
reviews were inspected for further sources. Additional information was
collected from an unpublished investigational brochure for galantamine.
SELECTION CRITERIA: Trials selected were randomized, double-blind,
parallel-group, unconfounded comparisons of galantamine with placebo for
a treatment duration of greater than 4 weeks for people with AD. DATA
COLLECTION AND ANALYSIS: Data were extracted independently by the
reviewers and pooled where appropriate and possible. The pooled odds
ratios (95%CI) or the average differences (95%CI) were estimated.
Intention-to-treat and observed cases data were both reported, if the
data were available. \~bullet\~Outcomes of interest include the
Alzheimer\'s Disease Assessment Scale-cognitive subscale (ADAS-cog),
clinical global impression of change (CIBIC-plus or CGIC), Alzheimer\'s
Disease Cooperative Study Activities of Daily Living Scale (ADCS-ADL),
Disability Assessment for Dementia scale (DAD) and Neuropsychiatric
Inventory (NPI). \~bullet\~Potential moderating variables of a treatment
effect included trial duration and dose. MAIN RESULTS: Seven trials were
identified that met criteria for entry, with six being Phase II or III
industry-sponsored multicentre trials. Two were of 12 weeks duration;
one of 13 weeks, one of 5 months; one of 29 weeks; and two of 6 months
duration. Trials of 5 months or more were aggregated together in the
analyses as \'6 months.\' Overall, galantamine showed significant
treatment effects at daily doses of 16-32 mg for trials of 3- to
6-months duration. For global ratings, trials of 3 months duration with
doses of 24-32mg/d (Odds Ratio (OR) 2.3; 95%CI 1.3 - 3.9) and 36mg/d (OR
3.4; 95%CI 1.2 - 9.5) were statistically significant in favour of
treatment. For trials of 6 months duration (5-months to 29 weeks), only
doses of 8mg/d failed to be associated with statistically significant
benefit (16mg: OR 2.25; 95% CI 1.6 - 3.3; 24mg: OR 2.0; 95%CI 1.5 -2.5;
32mg: OR 1.9; 95%CI 1.4 - 2.5). For cognitive function over 6 months
duration: at 16mg/d, improvements measured -3.3 points (k=1; 95%CI
-4.4 - -2.1) on weighted mean difference on the ADAS-Cog scale; -3.5
points at 24mg/d (k=3; 95%CI -4.3 - -2.8), and -4.0 points at 32mg/d
(k=2; 95%CI -5.0 - -3.0). The two 3-month trials with ADAS-Cog data also
showed statistically significant improvement. Both observed cases (WMD
3.8; 95%CI 0.3 - 7.3) and intention-to-treat analyses using the
Disability Assessment of Dementia scale gave statistically significant
results in favour of treatment for daily doses of 32mg for 6 months
duration (as did the single 3-month trial of 24-32mg/d treatment that
used this scale). The small number of trials available for analysis,
however, limited the power of subgroup analyses to detect differences.
Galantamine consistently failed to show statistically significant
treatment effects at doses of 8mg/day. Galantamine\'s adverse effects
appear similar to those of other cholinesterase inhibitors, in that it
tends to produce gastrointestinal symptoms acutely and with dosage
increases. Overall, participants treated with galantamine at all doses
for 3 months were more likely to discontinue that were those given
placebo. Participants treated with galantamine at doses of 24-32 mg/d
for 6 months were more likely to discontinue in most trials than were
those treated with lower doses or placebo, with 32mg/d being associated
with significantly higher withdrawal rates than was 24mg/d. However, in
the one trial with a slower rate of titration the discontinuation rate
was not significantly greater than placebo for the 16 mg/day dose.
REVIEWER\'S CONCLUSIONS: Patients in these trials were similar to those
seen in earlier anti dementia AD trials, and consisted predominantly of
mildly to moderately impaired outpatients. Galantamine\'s effects on
more severely impaired people has not yet been assessed. Never the less,
this review shows consistent positive effects for galantamine for trials
of 3 months, 5 months and 6 months duration. In addition, although there
was not a statistically significant dose-response effect, benefits
associated with doses above 8mg/d were, for the most part, consistently
statistically significant. There is therefore evidence for efficacy of
galantamine on global ratings, cognitive tests, assessments of ADLs and
behaviour. This magnitude for the cognitive effect is similar to that
associated with other cholinesterase inhibitors including donepezil,
rivastigmine, and tacrine. Galantamine\'s safety profile is similar to
that of other cholinesterase inhibitors with regard to cholinergically
mediated gastrointestinal symptoms. No information is available on
adverse events that occurred less than 5% of the time. It appears that
doses of 16 mg/d were best tolerated in the single trial where
medication was titrated over 4-week periods, and because this dose
showed statistically indistinguishable efficacy with higher doses, it is
probably preferable initially. Longer-term use of galantamine has not
been assessed in a controlled fashion.

554\. Pacheco, G., R. Palacios-Esquivel, and D.E. Moss, *Cholinesterase
inhibitors proposed for treating dementia in Alzheimer\'s disease:
selectivity toward human brain acetylcholinesterase compared with
butyrylcholinesterase.* J Pharmacol Exp Ther, 1995. 274(2): p. 767-70.
One consistent finding in senile dementia of the Alzheimer\'s type is
that the brain has reduced ability to synthesize acetylcholine. This has
been related, in part, to memory dysfunctions. Although a cholinergic
deficit is not singularly responsible for symptoms of dementia,
treatment strategies have been designed to facilitate cholinergic
activity by inhibiting acetylcholinesterase (AChE). To minimize
toxicity, however, a cholinesterase inhibitor selective for only AChE
would be an ideal treatment. The purpose of this study was to determine
the selectivity of physostigmine, metrifonate, methanesulfonyl fluoride
and tetrahydroaminoacridine (tacrine) toward AChE as compared with
butyrylcholinesterase (BChE) in human cortex. The results show that
methanesulfonyl fluoride is selective as an inhibitor of AChE as
compared with BChE. Physostigmine inhibited AChE more than BChE.
Metrifonate was found to inhibit BChE more than AChE.
Tetrahydroaminoacridine inhibited both enzymes in a complex way.

555\. Parent, A., C. Csonka, and P. Etienne, *The occurrence of large
acetylcholinesterase-containing neurons in human neostriatum as
disclosed in normal and Alzheimer-diseased brains.* Brain Res, 1984.
291(1): p. 154-8. The human neostriatum was found to contain large
neurons (maximum diameter: 30-40 microns) that stain intensely for
acetylcholinesterase (AChE). These neurons are few in number,
representing less than 5% of the total striatal neuronal population, and
appear uniformly scattered throughout the caudate nucleus and putamen.
They are morphologically similar to the AChE-containing neurons
disclosed in the striatum of rat, cat and monkey after AChE inhibitor
(DFP) pretreatment. In Alzheimer-diseased brains the number,
morphological characteristics, and staining intensity of the striatal
AChE neurons were found to be unaltered despite a marked loss of AChE
cells in the adjoining nucleus basalis. These findings suggest that
large intrinsic cholinergic neurons exist in human neostriatum and that
these elements, in contrast to those of nucleus basalis, are not
affected in Alzheimer\'s disease.

556\. Parnetti, L., *Clinical pharmacokinetics of drugs for Alzheimer\'s
disease.* Clin Pharmacokinet, 1995. 29(2): p. 110-29. Pharmacological
treatment of patients with Alzheimer\'s disease is becoming more
important, as evidenced by the number of drugs being developed in
different countries. It has been shown in the majority of clinical
trials that cholinesterase inhibitors, such as tacrine
(tetrahydroaminoacridine), are able to induce beneficial effects in
cognition and memory. Tacrine, like most of the other oral antidementia
agents, is rapidly absorbed from the gastrointestinal tract. It is
excreted mainly through the kidney, with a terminal elimination
half-life of about 3 hours. Tacrine has nonlinear pharmacokinetics and
there are large interindividual differences in pharmacokinetic
parameters after oral, intravenous and rectal administration. A positive
relationship between cognitive changes and plasma tacrine concentrations
has been recently described. Similarly, velnacrine exhibits evidence of
nonlinearity in some pharmacokinetic parameters, but renal excretion is
a minor route of elimination for this drug. Pharmacokinetic data
pertaining to eptastigmine, a third cholinesterase inhibitor, is more
limited. However, the drug is rapidly distributed to the tissues after
oral administration and readily enters the central nervous system, where
it can be expected to effectively inhibit acetylcholinesterase in the
brain for a prolonged period. Pharmacokinetic data for the nootropic
agents are more limited. However, of the 3 agents reviewed only
pramiracetam penetrates the central nervous system (CNS) poorly. Indeed,
oxiracetam crosses the blood-brain barrier and persists for longer in
the CNS than in the serum. Selegiline (deprenyl), a neuroprotective
agent, is readily absorbed from gastrointestinal tract. It is
metabolised mainly in the liver, and to a minimal extent in the lung or
kidneys. The steady-state concentrations of metabolites in the
cerebrospinal fluid (CSF) and serum are very similar, reflecting their
easy penetration into the CNS. Idebenone, another neuroprotective agent,
likewise is rapidly absorbed and achieves peak concentrations in the
brain comparable to those in plasma. Similarly, CSF concentrations of
metabolites of ST 200 (acetyl-L-carnitine) parallel those in plasma,
suggesting that they easily cross the blood-brain-barrier. Gangliosides
(GM1) can be given intramuscularly or subcutaneously, but the latter
route of administration provides a concentration 50% higher both in the
serum and the ganglioside fraction. However, because of its longer
elimination, the intramuscular route is the best form of administration
when the brain is the target organ for the treatment. Absorption of
nimodipine is quite rapid. The pharmacokinetics of nimodipine during
multiple-dose treatment have not been studied extensively; however, the
drug does not appear to accumulate during repeated administration of
standard doses.(ABSTRACT TRUNCATED AT 400 WORDS).

557\. Pearson, V.E., *Galantamine: a new alzheimer drug with a past
life.* Ann Pharmacother, 2001. 35(11): p. 1406-13. OBJECTIVE: To review
the historic, pharmacologic, pharmacokinetic, therapeutic, and
toxicologic features of galantamine, a new acetylcholinesterase
inhibitor, and to assess its role in the treatment of Alzheimer disease
symptoms. DATA SOURCES: A search of articles was conducted using
MEDLINE, TOXLINE, and the literature database Psychinfo, from 1966 to
June 1999. The manufacturers, Janssen and SoPharm (Bulgaria), were
contacted to obtain relevant preclinical data. Published textbooks of
meeting symposia were also reviewed. STUDY SELECTION: Studies with
animals and humans addressing preclinical pharmacology, human studies on
pharmacokinetics, open clinical trials, and controlled studies were
evaluated. DATA EXTRACTION: Relevant data were extracted from published
studies and meeting abstracts only. DATA SYNTHESIS: Galantamine has an
extensive record of activity as a reversal agent for neuromuscular
blockade. Galantamine is also effective in the treatment of mild to
moderate Alzheimer disease symptoms. Its efficacy versus similar
Alzheimer treatment agents has yet to be determined. Adverse effects are
gastrointestinal in nature and usually appear during the first weeks of
therapy. CONCLUSIONS: Galantamine is a useful agent for the treatment of
Alzheimer disease and for the reversal of neuromuscular blockade. It
acts as both an acetylcholinesterase inhibitor and a nicotinic receptor
agonist.

558\. Peters, B.H. and H.S. Levin, *Effects of physostigmine and
lecithin on memory in Alzheimer disease.* Ann Neurol, 1979. 6(3): p.
219-21. Because there is evidence that central cholinergic mechanisms
are depleted in dementia, we studied the effects of central cholinergic
augmentation on the memory of 5 patients with Alzheimer disease.
Patients received placebo, lecithin, physostigmine, or lecithin plus
physostigmine in a double-blind study using titrated doses of the
acetylcholinesterase inhibitor physostigmine. Memory was evaluated with
alternate forms of the selective reminding procedure. Compared with
lecithin alone, the combination of physostigmine and lecithin
consistently enhanced memory storage and retrieval; physostigmine
without lecithin produced no memory facilitation. The strategy of
combining a cholinergic agonist and precursor holds promise, although a
larger clinical trial is needed.

559\. Pettigrew, L.C., *et al.*, *Pharmacokinetics, pharmacodynamics,
and safety of metrifonate in patients with Alzheimer\'s disease.* J Clin
Pharmacol, 1998. 38(3): p. 236-45. Metrifonate is converted
nonenzymatically to 2.2, dimethyl dichlorovinyl phosphate (DDVP), an
inhibitor of acetylcholinesterase (AChE). This 21-day, randomized,
double-blind, placebo-controlled trial of metrifonate in patients with
Alzheimer\'s disease (n = 27) evaluated four doses, each administered
orally once daily. All patients received a loading dose (LD) for 6 days
followed by a maintenance dose (MD) for 15 days. The treatment groups
were: panel 1, LD = 1.5 mg/kg (75-135 mg), MD = 0.25 mg/kg (12.5-25 mg);
panel 2, LD = 2.5 mg/kg (125-225 mg), MD = 0.40 mg/kg (20-35 mg); panel
3, LD = 4.0 mg/kg (200-335 mg), MD = 0.65 mg/kg (30-60 mg); and panel 4,
LD = 4.0 mg/kg (200-335 mg), MD = 1.0 mg/kg (50-90 mg). All metrifonate
doses were well tolerated. Most adverse events were mild to moderate in
intensity, gastrointestinal in nature, and transient. Mean area under
the concentration-time curve (AUC) and maximum concentration (Cmax) for
both metrifonate and DDVP increased in relation to dose. Metrifonate and
DDVP had similar, largely dose-independent mean values for time to Cmax
(tmax) and half-life (t1/2). There was little or no accumulation of
either metrifonate or DDVP with long-term administration. After 21 days
of treatment, mean percent erythrocyte AChE inhibition was 14%, 35%,
66%, 77%, and 82% for placebo and panels 1 through 4, respectively.
Cognitive improvement was observed with the two highest metrifonate
doses. These results reflect favorable safety and pharmacokinetic
profiles for the use of metrifonate in the treatment of Alzheimer\'s
disease.

560\. Poirier, J., *et al.*, *Apolipoprotein E4 allele as a predictor of
cholinergic deficits and treatment outcome in Alzheimer disease.* Proc
Natl Acad Sci U S A, 1995. 92(26): p. 12260-4. Apolipoprotein E (apoE)
is critical in the modulation of cholesterol and phospholipid transport
between cells of different types. Human apoE is a polymorphic protein
with three common alleles, APO epsilon 2, APO epsilon 3, and APO epsilon
4. ApoE4 is associated with sporadic and late-onset familial Alzheimer
disease (AD). Gene dose was shown to have an effect on risk of
developing AD, age of onset, accumulation of senile plaques in the
brain, and reduction of choline acetyltransferase (ChAT) activity in the
hippocampus of AD subjects. To characterize the possible impact of the
apoE4 allele on cholinergic markers in AD, we examined the effect of
apoE4 allele copy number on pre- and postsynaptic markers of cholinergic
activity. ApoE4 allele copy number showed an inverse relationship with
residual brain ChAT activity and nicotinic receptor binding sites in
both the hippocampal formation and the temporal cortex of AD subjects.
AD cases lacking the apoE4 allele showed ChAT activities close or within
age-matched normal control values. The effect of the apoE4 allele on
cholinomimetic drug responsiveness was assessed next in a group (n = 40)
of AD patients who completed a double-blind, 30-week clinical trial of
the cholinesterase inhibitor tacrine. Results showed that \> 80% of
apoE4-negative AD patients showed marked improvement after 30 weeks as
measured by the AD assessment scale (ADAS), whereas 60% of apoE4
carriers had ADAS scores that were worse compared to baseline. These
results strongly support the concept that apoE4 plays a crucial role in
the cholinergic dysfunction associated with AD and may be a prognostic
indicator of poor response to therapy with acetylcholinesterase
inhibitors in AD patients.

561\. Poirier, J., *Evidence that the clinical effects of cholinesterase
inhibitors are related to potency and targeting of action.* Int J Clin
Pract Suppl, 2002(127): p. 6-19. Since degenerative alterations
associated with cholinergic changes in the brains of demented patients
occur in specific regions, optimal efficacy may be achieved by targeting
the actions of potent cholinesterase inhibitors in relevant regions.
When evaluating the activities of these agents, only cerebrospinal fluid
(CSF)-based studies in demented patients provide reliable data.
Preclinical or healthy volunteer studies of cholinesterase inhibitory
activity using plasma or erythrocytes as an enzyme source are
inconclusive due to differences between enzymes, their relative
activities, and the profiles of their isoforms from different sources,
with additional changes during disease progression. Tacrine and
rivastigmine inhibit both acetylcholinesterase (AChE) and
butyrylcholinesterase (BuChE) in the CSF of Alzheimer\'s disease
patients. Both enzymes are involved in the breakdown of acetylcholine
(ACh) in the brain and dual inhibition may lead to greater, broader
efficacy, as well as a greater potential for disease modification.
However, potent and rapid elevation in levels of ACh may also induce
more acute tolerability problems, such as nausea and vomiting. Only
rivastigmine appears to show brain region-selectivity, particularly for
regions involved in attention and behaviour and that are known to
degenerate during the progression of various dementia types. This
selectivity is due to preferential inhibition of the G1 form of AChE
and, probably, also BuChE. Cholinesterase inhibitors that lack
preferential selectivity for particular isoforms may provide less
targeted actions. This may explain the relatively higher incidences of
certain peripheral side effects observed during maintenance treatment
with some of these drugs. All cholinesterase inhibitors interact via
ACh, additionally available due to enzyme inhibition, with nicotinic and
muscarinic receptors (nAChRs and mAChRs). Allosteric modulation of a
presynaptic nAChR has been shown in vitro with many of these agents, and
it has been proposed, but not demonstrated, that this may result in an
increased release and potentiation of ACh in the brain. The clinical
relevance of this mechanism is unknown. The rapidly reversible actions
of donepezil, tacrine and galantamine may lead to tolerance due to their
ability to upregulate target enzyme activities; however upregulation is
not seen with the slowly reversible (pseudo-irreversible) inhibitor
rivastigmine. Available clinical data support the hypothesis that
potent, slowly reversible inhibitors of AChE and BuChE targeted to the
G1 isoforms may lead to greater, broader and more sustained benefits.
However, further investigation of the cholinesterase inhibitors to
elucidate more definitely the clinical consequences of their differing
pharmacological properties is required.

562\. Polinsky, R.J., *Clinical pharmacology of rivastigmine: a
new-generation acetylcholinesterase inhibitor for the treatment of
Alzheimer\'s disease.* Clin Ther, 1998. 20(4): p. 634-47. Rivastigmine
(ENA 713, or carbamoylatine) is an acetylcholinesterase (AChE) inhibitor
with brain-region selectivity and a long duration of action. Both
preclinical studies and studies in human volunteers have shown that
rivastigmine induces substantially greater inhibition of AChE in the
central nervous system (CNS) compartment than in the periphery (40%
inhibition of central AChE compared with 10% inhibition of plasma
butylcholinesterase in healthy volunteers). Moreover, rivastigmine
preferentially inhibits the G1 enzymatic form of AChE, which
predominates in the brains of patients with Alzheimer\'s disease (AD).
Evidence from animal studies also suggests that rivastigmine is a more
potent inhibitor of AChE in the cortex and hippocampus, the brain
regions most affected by AD. Absorption of rivastigmine is rapid and
almost complete (\>96% of the administered dose). Extensive, saturable
first-pass metabolism, however, leads to bioavailability of
approximately 35% of the administered dose and nonlinear
pharmacokinetics. The principal metabolite of rivastigmine has at least
10-fold lower activity against AChE compared with the parent drug.
Rivastigmine is completely metabolized; the major route of elimination
of the metabolites is renal. Although patients with AD demonstrate 30%
to 50% higher plasma concentrations of rivastigmine and its principal
metabolite than do healthy elderly patients, there is no evidence of
drug accumulation, which is consistent with rivastigmine\'s short
pharmacokinetic half-life. Distribution of rivastigmine into the CNS is
extensive, and inhibition of AChE in the cerebrospinal fluid is
detectable 1.2 hours after oral dosing in both healthy volunteers and
patients with AD. Peak activity is reached somewhat more slowly in AD
patients than in healthy subjects, and the inhibitory effects have a
longer duration (6.0 vs 2.4 hours and 12.0 vs 8.5 hours, respectively).
Rivastigmine is inactivated during the process of interacting with and
inhibiting AChE, and, in contrast to other AChE inhibitors, the hepatic
cytochrome P-450 (CYP-450) system is not involved in the metabolism of
rivastigmine. This reduces its propensity to interact with drugs
metabolized by specific CYP-450 isoenzymes. Consistent with
rivastigmine\'s pharmacokinetic and pharmacodynamic profiles, Phase II
and III trials have demonstrated that the drug is a well-tolerated and
effective treatment for AD.

563\. Rainer, M., *et al.*, *Cognitive relapse after discontinuation of
drug therapy in Alzheimer\'s disease: cholinesterase inhibitors versus
nootropics.* J Neural Transm, 2001. 108(11): p. 1327-33. In a
cross-sectional study of outpatients diagnosed with dementia of the
Alzheimer type who had been treated with a broad variety of drugs
supposed to improve cognition or to delay cognitive decline, we have
investigated the effects of abruptly discontinuing therapy on cognition.
Termination of therapy with any cholinesterase inhibitor was associated
with a cognitive decline during the following 6-7 weeks which was
significantly more pronounced than that experienced by patients who had
received nootropic drugs or calcium channel blockers (3.41 vs. 1.17
points on the ADAS-Cog scale; -1.14 vs. -0.06 points on the MMSE scale).
This effect was not modified by gender, apolipoprotein E genotype, or
the extent of ventricular enlargement on CT scans. Its magnitude was
comparable to the cognitive response observed in published clinical
trials when cholinesterase therapy commenced, and also with the data
obtained during a 6-week placebo washout phase.

564\. Raskind, M.A., *et al.*, *The effects of metrifonate on the
cognitive, behavioral, and functional performance of Alzheimer\'s
disease patients. Metrifonate Study Group.* J Clin Psychiatry, 1999.
60(5): p. 318-25. BACKGROUND: The objective of this study was to
evaluate the efficacy and safety of metrifonate, a long-acting
acetylcholinesterase inhibitor, in patients clinically diagnosed with
probable Alzheimer\'s disease of mild-to-moderate severity. METHOD: This
was a prospective, multicenter, 26-week, double-blind, parallel group
study. The 264 randomized patients met diagnostic criteria of the
National Institute of Neurological and Communicative Diseases and Stroke
and the Alzheimer\'s Disease and Related Disorders Association for
probable Alzheimer\'s disease. Patients had Mini-Mental State
Examination (MMSE) scores of 10-26 and ischemic scores (Rosen
modification) of \<4. Metrifonate-treated patients received a single
50-mg dose once daily. The efficacy of metrifonate was investigated with
respect to 3 symptom domains. Cognitive performance was analyzed using
the Alzheimer\'s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog)
and the MMSE. Psychiatric and behavioral disturbances were analyzed
using the Neuropsychiatric Inventory (NPI) and the ADAS-Noncognitive
subscale (ADAS-Noncog). The ability to perform instrumental and basic
activities of daily living was evaluated using the Disability Assessment
for Dementia (DAD) scale. Additionally, global state was assessed using
the Clinician Interview-Based Impression of Change with Caregiver Input
(CIBIC-Plus) scale. RESULTS: After 26 weeks of metrifonate therapy, a
statistically significant benefit of metrifonate was observed in the
cognitive performance of Alzheimer\'s disease patients (ADAS-Cog, t =
2.55, df = 237, p = .012; MMSE, t = 4.60, df = 237, p = .0001).
Metrifonate also significantly attenuated the deterioration in
activities of daily living of the patients (DAD total score, t = -2.11,
df = 233, p = .036) and relieved patients\' psychiatric and behavioral
disturbances (NPI total score, t = 2.51, df = 233, p = .013). In
addition, metrifonate significantly improved the scores for the global
state of the patients (CIBIC-Plus, t = 2.07, df = 232, p = .039).
Metrifonate was well tolerated; adverse events were predominantly mild
in intensity, and no hepatotoxicity was observed. CONCLUSION: In this
study, metrifonate was safe and well tolerated. It benefited the
cognitive decline, psychiatric and behavioral disturbances, impaired
ability to perform instrumental and basic activities of daily living,
and global state of patients diagnosed with mild-to-moderate
Alzheimer\'s disease.

565\. Rogers, S.L., *Perspectives in the management of Alzheimer\'s
disease: clinical profile of donepezil.* Dement Geriatr Cogn Disord,
1998. 9 Suppl 3: p. 29-42. Donepezil HCI is a piperidine-based
reversible acetylcholinesterase (AChE) inhibitor, chemically distinct
from other cholinesterase (ChE) inhibitors and rationally designed to
treat the symptoms of Alzheimer\'s disease (AD). It is highly selective
for AChE in the central nervous system (CNS), with little or no affinity
for butyrylcholinesterase (BuChE). In preclinical studies in animals,
donepezil produced increased CNS acetylcholine. The resultant
enhancement of cholinergic activity gave rise to improved performance by
rats on tests of learning and memory, with no evidence of hepatic or
renal toxicity. In subsequent phase I clinical evaluations in healthy
volunteers, donepezil demonstrated favorable pharmacokinetic,
pharmacodynamic and safety profiles. Its long terminal disposition
half-life supported once-daily administration, with no requirement for
dose modification in the elderly or in patients with renal or hepatic
impairment. A 14-week, phase II dose-finding study in patients with mild
to moderate AD (Clinical Dementia Rating \[CDR\], 1-2; Mini-Mental State
Examination \[MMSE\], 10-26) showed that donepezil at a dose of 5 mg/day
produced highly significant improvements in cognition (as measured by
the Alzheimer\'s Disease Assessment Scale, cognitive subscale
\[ADAS-cog\]). Subsequently, two pivotal parallel-group,
placebo-controlled phase III trials (of 15 and 30 weeks\' duration)
showed highly statistically significant improvements in ADAS-cog, MMSE,
Clinician\'s Interview-Based Impression of Change with caregiver input
(CIBIC plus) and CDR-SB (Sum of the Boxes) scores, compared with
placebo, in mild to moderate AD patients treated with either 5 or 10
mg/day donepezil. Adverse events in the phase II and III trials were
mild and transient and resolved with continued donepezil administration.
The donepezil clinical trials program has shown that this drug is a
clinically effective and well-tolerated once-daily treatment for the
symptoms of mild to moderate AD.

566\. Rogers, S.L., *et al.*, *Donepezil improves cognition and global
function in Alzheimer disease: a 15-week, double-blind,
placebo-controlled study. Donepezil Study Group.* Arch Intern Med, 1998.
158(9): p. 1021-31. BACKGROUND: Donepezil hydrochloride (Aricept) is a
selective acetylcholinesterase inhibitor developed for the treatment of
Alzheimer disease. This phase 3 study was 1 of 2 pivotal trials
undertaken to establish the efficacy and safety of using donepezil in
patients with mild to moderately severe Alzheimer disease. OBJECTIVES:
To further examine the efficacy and safety of using donepezil in the
treatment of patients with mild to moderately severe Alzheimer disease.
To examine the relationships between plasma donepezil concentrations,
inhibition of red blood cell acetylcholinesterase activity, and clinical
response. METHODS: This was a 12-week, double-blind, placebo-controlled,
parallel-group trial with a 3-week single-blind washout. Outpatients at
23 centers in the United States were randomized to receive placebo, 5 mg
of donepezil hydrochloride, or 10 mg of donepezil hydrochloride (5 mg/d
during week 1 then 10 mg/d thereafter) administered once daily at
bedtime. Primary efficacy was measured using the Alzheimer\'s Disease
Assessment Scale-Cognitive Subscale (ADAS-cog) and Clinician\'s
Interview-Based Impression of Change including caregiver information
(CIBIC plus). RESULTS: A total of 468 patients entered the study, more
than 97% of whom were included in the intention-to-treat (end point)
analyses. The use of donepezil produced statistically significant
improvements in ADAS-cog, CIBIC plus, and Mini-Mental State Examination
scores, relative to placebo. The mean drug-placebo differences, at end
point, for the groups receiving 5 mg/d and 10 mg/d of donepezil
hydrochloride were, respectively, 2.5 and 3.1 units for ADAS-cog
(P\<.001); 0.3 and 0.4 units for CIBIC plus (P\< or =.008); and 1.0 and
1.3 units for Mini-Mental State Examination (P\< or =.004). On the CIBIC
plus scale, 32% and 38% of patients, respectively, treated with 5 mg/d
and 10 mg/d of donepezil hydrochloride demonstrated clinical improvement
(a score of 1, 2, or 3) compared with placebo (18%). The mean (+/-SEM)
donepezil plasma concentrations at study end point were 25.9 +/- 0.7
ng/mL and 50.6 +/- 1.9 ng/mL in the groups receiving dosages of 5 mg/d
and 10 mg/d, respectively. Corresponding mean (+/-SEM) percentages of
inhibition of red blood cell acetylcholinesterase activity were 63.9%
+/- 0.9% and 74.7% +/- 1.2% for these 2 dosages, respectively. There was
a statistically significant positive correlation between plasma
concentrations of donepezil and acetylcholinesterase inhibition; the
EC50 (50% effect) was obtained at a concentration of 15.6 ng/mL. A
plateau of inhibition (80%-90%) was reached at plasma donepezil
concentrations higher than 50 ng/mL. The correlations between plasma
drug concentrations and both ADAS-cog (P\<.001) and CIBIC plus (P =
.006) were also statistically significant, as were the correlations
between red blood cell acetylcholinesterase inhibition and change in
ADAS-cog (P\<.001) and CIBIC plus (P = .005). The incidence of
treatment-emergent adverse events with both dosages of donepezil
(68%-78%) was comparable with that observed with placebo (69%). The use
of 10 mg/d of donepezil hydrochloride was associated with transient mild
nausea, insomnia, and diarrhea. There were no treatment-emergent
clinically significant changes in vital signs or clinical laboratory
test results. More important, the use of donepezil was not associated
with the hepatotoxic effects observed with acridine-based cholinesterase
inhibitors. CONCLUSION: Donepezil hydrochloride (5 and 10 mg)
administered once daily is a well-tolerated and efficacious agent for
treating the symptoms of mild to moderately severe Alzheimer disease.

567\. Rouhart, F., *\[New therapeutic prospects in Alzheimer disease\].*
Rev Med Interne, 1995. 16(11): p. 860-3. The approval for marketing of
tacrine (Cognex), an acetylcholinesterase inhibitor, allowed physicians
and the general people to attract attention to a degenerative disease,
which prevalence dramatically increases every year. This drug is
hopeful. Meanwhile, we must keep in mind that it has only a symptomatic
effect. Its hepatotoxicity requires regular biological tests. Many
medications are actually in earlier stages of development along with
various etiological approaches.

568\. Samuels, S.C. and K.L. Davis, *A risk-benefit assessment of
tacrine in the treatment of Alzheimer\'s disease.* Drug Saf, 1997.
16(1): p. 66-77. Tacrine, the first drug specifically approved for
Alzheimer\'s disease, produces symptomatic improvement. The theoretical
rationale behind treating Alzheimer\'s disease with tacrine is based on
central cholinergic depletion. Tacrine is centrally acting,
uncompetitive reversible inhibitor of acetylcholinesterase and
butyrylcholinesterase. Multiple clinical trials support the
effectiveness of tacrine in Alzheimer\'s disease. High dosages of
tacrine are required for efficacy, with the potential for hepatic and
mild gastrointestinal adverse effects. However, the benefits of tacrine
currently outweigh its risks, and a trial of the drug should be offered
to patients. As clinical experience with tacrine increases, the long
term risk-benefit equation may be refined.

569\. Scott, L.J. and K.L. Goa, *Galantamine: a review of its use in
Alzheimer\'s disease.* Drugs, 2000. 60(5): p. 1095-122. Currently,
acetylcholinesterase (AChE) inhibitors are the most promising class of
drugs for the treatment of Alzheimer\'s disease (AD). Galantamine is a
reversible, competitive, tertiary alkaloid AChE inhibitor. The drug is
selective for AChE rather than butyrylcholinesterase. In addition to
inhibition of AChE galantamine interacts allosterically with nicotinic
acetylcholine receptors to potentiate the action of agonists at these
receptors. Recipients of galantamine 16 or 24 mg/day achieved
significant improvements in cognitive and global symptoms relative to
placebo recipients in large (n = 285 to 978 patients with mild to
moderate AD) well-designed trials of 3 to 6 months\' duration.
Galantamine also improved activities of daily living in these patients
and significantly reduced the requirement for caregiver assistance with
activities of daily living. Moreover, galantamine recipients achieved
significantly better outcomes on behavioural symptoms than placebo
recipients. In a long term study (12 months), galantamine 24 mg/day
slowed the progression of symptoms of the disease and maintained
cognitive function and activities of daily living in patients with mild
to moderate AD. Galantamine was generally well tolerated with the
majority of adverse events being mild to moderate in intensity and
transient. Predictably, adverse events were cholinergic in nature and
generally related to the gastrointestinal system. These effects were
reduced in patients receiving the recommended dose escalation regimen.
Galantamine had no clinically relevant effects on vital signs,
haematological or biochemical laboratory parameters and, importantly,
there were no reports of hepatotoxicity. The incidence of serious
adverse events was similar between galantamine (8 to 32 mg/day) and
placebo groups (6 to 16% of patients across all treatment groups).
CONCLUSIONS: Galantamine is an effective well tolerated symptomatic
treatment for AD which improves cognition, function and activities of
daily living in the short term (up to 6 months) in patients with mild to
moderate AD. In addition, it delays the development of behavioural
disturbances and psychiatric symptoms, and reduces caregiver burden (as
measured by caregiver time). In the long term (up to 1 year),
galantamine maintains cognition and activities of daily living. Adverse
events associated with galantamine are mainly cholinergic, usually mild
to moderate in intensity and transient. Galantamine has been evaluated
in several large well-designed studies and, given the relative lack of
established treatment options, it may be considered as one of the
first-line pharmacological treatments in patients with mild to moderate
AD.

570\. Shen, Z.X., *The significance of the activity of CSF
cholinesterases in dementias.* Med Hypotheses, 1996. 47(5): p. 363-76.
This article reviews the significance of changes in the level of
cerebrospinal fluid acetylcholinesterase or cholinesterase in patients
with Alzheimer\'s disease or other dementias. Evidence has shown that
the methodology of assaying cerebrospinal fluid acetylcholinesterase or
cholinesterase is reliable and the activity of the enzyme is stable. Low
acetylcholinesterase or cholinesterase levels presenting in
cerebrospinal fluid of a demented individual may confirm the clinical
diagnosis of Alzheimer\'s disease or other organic dementia. A low
activity of acetylcholinesterase or cholinesterase existing in
cerebrospinal fluid of a non-demented individual may indicate a brain at
risk, or that the person is in the preclinical stage of dementia.
Recognition of the presence of the preclinical stage may be very
beneficial for explaining the real meaning of the \'overlap\' in the
biochemistry and pathology between dementia and non-dementia, and also
very important for prevention and treatment. Therefore, the strategy of
prevention and of treatment should no longer be designed to inhibit
acetylcholinesterase activity. In contrast, it should be designed to
enhance the neuronal acetylcholinesterase activity or to delay the
degeneration of brain acetylcholinesterase system.

571\. Shen, Z.X., *CSF cholinesterase activity in demented and
non-demented subjects.* Neuroreport, 1998. 9(3): p. 483-8. Samples of
cerebrospinal fluid (CSF) were examined, looking mainly at total
cholinesterase (ChE) and acetyl-cholinesterase (AChE) levels from 139
living subjects. At the completion of the study, 35 of the 139 patients
had died and pathological confirmation of the presence of dementia had
been obtained. These results, together with results from other
laboratories, provide evidence that a low CSF ChE level presenting in
demented patients may indicate a depletion of the brain AChE system, and
this may confirm a clinical diagnosis of AD as well as other types of
dementia which are associated with an alteration of the brain AChE
system. The overlap in the levels of CSF biochemical markers between
demented and non-demented subjects which has led to many conflicting
reports has always disappointed investigators. It is suggested that some
\'control\' subjects with CSF ChE activity indistinguishable from that
in AD patients may have an abnormal ageing process in their brains
(brain at risk), although the symptoms of dementia have not yet been
detected. Recognition of a pre-clinical or incubation period is very
beneficial for explaining discrepancies in biochemistry and pathology in
the literature, and must be considered for both the treatment and the
prevention of dementia. The long used treatment, which was designed to
inhibit AChE, should no longer be used: treatment must be designed to
enhance the activity of the neuronal AChE system, or slow its
degeneration.

572\. Sherman, K.A. and E. Messamore, *Cholinesterase inhibitor therapy
for Alzheimer dementia: what do animal models tell us?* Prog Clin Biol
Res, 1989. 317: p. 1209-22. Despite a strong rationale for the use of
cholinesterase (ChE) inhibitors and related drugs to augment cholinergic
function as palliative treatment for Alzheimer dementia, this approach
met with limited and variable success until the striking results
recently reported with tacrine (THA). Our previous studies have shown
the potential utility of blood ChE inhibition to define the optimum dose
of such drugs. In the present studies, THA was reinvestigated in rats
because several literature reports of weak inhibition of blood and brain
acetylcholinesterase (AChE) after systemic treatment leave unresolved
the mechanism of action for THA. Consistent with previous reports, we
find an in vitro IC50 of 1 microM THA or less for brain or red blood
cell AChE, dependent on the substrate concentration. Results were
independent of tissue dilution in vitro. However, after in vivo THA, the
inhibition of plasma ChE or brain AChE declined as a log function of
tissue dilution. These results indicate that the degree of inhibition is
underestimated as a result of dilution of tissue for enzyme assay. We
therefore used minimal tissue dilution to establish the dose-response
and time course functions after s.c. administration of THA and to
compare the effect of THA in various brain regions with that on blood
enzymes. Pons-medulla AChE was much less sensitive to the effects of THA
than hippocampus, cortex, cerebellum or plasma ChE, particularly at
doses of 2.5 mg/kg or less. In these other brain regions, AChE was
inhibited 22-44% after doses of 1.25 to 2.5 mg/kg THA, the dose range
which maximally improved retention performance in mice. Peak inhibition
occurred rapidly in plasma, but was delayed in brain (30-60 min after
THA). Inhibition was long-lasting in both plasma and cortex (greater
than or equal to 5 hr). It is concluded that long-lasting inhibition of
the metabolism of acetylcholine is the most heuristic explanation of
THA\'s pharmacological activity.

573\. Shigeta, M. and A. Homma, *Donepezil for Alzheimer\'s disease:
pharmacodynamic, pharmacokinetic, and clinical profiles.* CNS Drug Rev,
2001. 7(4): p. 353-68. Donepezil was developed in order to overcome the
disadvantages of physostigmine and tacrine. Its use is based on the
cholinergic hypothesis. Donepezil is a piperidine-based, reversible
acetylcholinesterase inhibitor, that is chemically unrelated to other
cholinesterase inhibitors. It was developed for the symptomatic
treatment of Alzheimer\'s disease (AD). Donepezil is highly selective
for acetylcholinesterase with a significantly lower affinity for
butyrylcholinesterase, which is present predominantly in the periphery.
Phase I and II clinical trials demonstrated donepezil\'s favorable
pharmacokinetic, pharmacodynamic and safety profile. There is no need to
modify the dose of donepezil in the elderly or in patients with renal
and hepatic failure. Pivotal phase-III trials in the US, European
countries, and Japan showed that donepezil significantly improved
cognition and global function in patients with mild to moderate AD. In
long-term trials, donepezil maintained cognitive and global function for
up to 1 year prior to the resumption of gradual deterioration. Donepezil
is generally well tolerated; most of its adverse events are mild,
transient and cholinergic in nature. Donepezil produces no clinically
significant changes in laboratory parameters, including liver function.
The drug is approved for the treatment of mild to moderate Alzheimer\'s
disease, but donepezil therapy does not have to be discontinued if a
patient continues to deteriorate. Possible new indications for donepezil
in psychiatric and neurologic diseases, other than AD, include dementia
with Lewy bodies, brain injury, attention deficit hyperactivity,
multiple sclerosis, Down\'s syndrome, delirium, mood disorders,
Huntington\'s disease and sleep disorders.

574\. Shih, J.H., *et al.*, *Acute effects of oral pyridostigmine
bromide on conditioned operant performance in rats.* Pharmacol Biochem
Behav, 1991. 38(3): p. 549-53. Pyridostigmine bromide (Pyr), the current
drug of choice in the management of myasthenia gravis, has been
suggested for use in Alzheimer\'s dementia, and as a prophylactic
treatment for intoxication with organophosphate cholinesterase
inhibitors. The present study was undertaken to evaluate the
dose-response and time-course effects of acute oral administration of
Pyr over a broad dose range (3-40 mg/kg) on the lever pressing of rats
maintained under a multiple fixed-ratio (FR-20) time-out schedule of
reinforcement for water reward. The drug produced a dose-dependent
biphasic response depression in the overall rate of FR responding. Low
doses of Pyr (less than or equal to 12 mg/kg) that caused no gross signs
of toxicity only moderately decreased rates of responding, primarily due
to a decrease in response rates. Whereas high doses of Pyr (greater than
24 mg/kg) which produced overt signs of peripheral cholinergic
intoxication markedly suppressed overall responding, primarily due to
cessation of responding. The lowest effective dose of performance
disruption was 6 mg/kg, and the ED50 was calculated as 23.3 (17.9-28.7)
mg/kg. The time-course data of performance disruption showed that low
doses of Pyr (less than or equal to 12 mg/kg) had an onset latency
within 40-80 min and a duration of 20-80 min, whereas high doses
(greater than or equal to 24 mg/kg) had an onset latency of 20-40 min
and a duration greater than 80 min. These results suggest the
recommended human therapeutic or prophylactic regimen of 30-120.mg Pyr,
orally taken each 8 hours, might adversely affect behavioral
performance.

575\. Shikiar, R., *et al.*, *The impact of metrifonate therapy on
caregivers of patients with Alzheimer\'s disease: results from the MALT
clinical trial. Metrifonate in Alzheimer\'s Disease Trial.* J Am Geriatr
Soc, 2000. 48(3): p. 268-74. OBJECTIVE: To assess the impact on burden
reported by caregivers of patients with mild to moderate Alzheimer\'s
disease (AD) who were treated with metrifonate during a randomized
double blind clinical trial. DESIGN: Randomized clinical trial, with a
2-week screening period and a 26-week double blind, placebo controlled,
treatment phase. Caregivers were assessed at baseline, at 12 weeks, and
at end of trial. SETTING: Caregivers were interviewed at clinics as part
of the assessment of the patients. PARTICIPANTS: Six hundred and three
caregivers of AD patients who were enrolled in the MALT trial; 591 (98%)
provided data suitable for analysis at baseline, and 546 (91%) provided
data allowing for inclusion in the analysis of change scores.
MEASUREMENTS: The Caregiver Burden Assessment consisted of the Screen
for Caregiver Burden, including both subjective (SCB-subj) and objective
(SCB-obj) scores; the cognitive subscale of Poulshock and Deimling (PD);
an abridged version of the Relatives Stress Scale (aRSS); assessments of
time spent in providing care, including the Caregiver Activity Time
Scale (CATS); and demographic and background variables on both the
patient and caregiver. RESULTS: Treatment of mild to moderate AD
patients with metrifonate for a duration of 26 weeks significantly
reduced the psychological burden of care to the caregivers, as measured
by the SCB-subj, the PD, and the aRSS. There were no statistically
significant differences on the measures assessing the time spent in
caregiving, except for the caregiver\'s subjective impression of the
change in time spent providing care during the trial. When comparing
individual dose groups, most of the measures of burden showed the
largest benefits in burden for the 60/80 mg group, followed by the 40/50
mg group, and then the placebo group. However, there was no
statistically significant dose effect. CONCLUSIONS: This study provides
the first evidence from a randomized clinical trial of any
acetylcholinesterase inhibitor used in the treatment of AD demonstrating
a positive impact on the patient\'s caregiver as well as benefits to the
patient. These results were shown consistently across several
measurement scales and were observed after six months of treatment.
These findings reinforce the clinical significance of research that has
shown that metrifonate has beneficial impacts on the cognitive,
behavioral, and functional abilities of AD patients. Because caregiver
burden is a leading factor in the decision for institutional care
placement, the ability to favorably impact that burden through
pharmacological treatment of the patient is important.

576\. Shintani, E.Y. and K.M. Uchida, *Donepezil: an anticholinesterase
inhibitor for Alzheimer\'s disease.* Am J Health Syst Pharm, 1997.
54(24): p. 2805-10. The pharmacology, pharmacokinetics, clinical
efficacy, adverse effects, drug interactions, and dosage and
administration of donepezil are reviewed. Donepezil is a synthetic
noncovalent reversible inhibitor of acetylcholinesterase (AChE) for the
treatment of mild to moderate dementia associated with Alzheimer\'s
disease. In contrast to tacrine hydrochloride, the only comparable agent
currently approved by FDA, donepezil exhibits a relatively high degree
of selectivity for neuronal AChE as opposed to butyrylcholinesterase. It
has a half-life of 60 hours in young adults and 104 hours in elderly
patients. In clinical trials, donepezil has been associated with
significant improvements in Alzheimer\'s Disease Assessment
Scale-cognitive subscale and Clinical Interview-Based Impression of
Change scores. The most common adverse effects associated with donepezil
are nausea, diarrhea, anorexia, and vomiting, which are most likely to
occur during dose initiation or adjustment. Hepatotoxicity, a
dose-limiting adverse effect that sometimes requires discontinuation of
tacrine, has not been reported with donepezil. Donepezil does not appear
to interact with theophylline, cimetidine, warfarin, or digoxin.
Ketoconazole and quinidine inhibit the metabolism of donepezil in vitro,
but there is a lack of clinical data showing that these drugs decrease
the clearance of donepezil. The initial recommended dosage is 5 mg daily
before bedtime, with a dosage increase to 10 mg after four to six weeks
according to the patient\'s response and tolerance. Donepezil appears to
be preferable to tacrine as the initial agent for patients with mild to
moderate dementia associated with Alzheimer\'s disease.

577\. Smith, C.P., *et al.*, *Pharmacological activity and safety
profile of P10358, a novel, orally active acetylcholinesterase inhibitor
for Alzheimer\'s disease.* J Pharmacol Exp Ther, 1997. 280(2): p.
710-20. 1-\[(3-Fluoro-4-pyridinyl)amino\]-3-methyl-1(H)-indol-5-yl
methyl carbamate (P10358) is a potent, reversible acetylcholinesterase
inhibitor that produces central cholinergic stimulation after oral and
parental administration in rats and mice. P10358 is a 2.5 times more
potent acetylcholinesterase inhibitor than THA in vitro (IC50 = 0.10 +/-
0.02 microM vs. IC50 = 0.25 +/- 0.03 microM). It also inhibits
butyrylcholinesterase activity as potently as THA (IC50 = 0.08 +/- 0.05
microM vs. IC50 = 0.07 +/- 0.01 microM). Ex vivo, P10358 (0.2 - 20
mg/kg, p.o.) produced dose-dependent inhibition of brain
acetylcholinesterase activity. At 10 and 20 mg/ kg, it produced profound
and long-lasting hypothermia in mice. P10358 enhanced performance in
rats in a step-down passive avoidance task (0.62 and 1.25 mg/kg) and in
a social recognition paradigm (0.32, 0.64 and 1.25 mg/kg) in mice. It
reversed scopolamine-induced deficits in the Morris Water maze in rats
(1.25 and 2.5 mg/kg) and a higher dose elevated striatal homovanillic
acid levels. These behavioral and biochemical effects are consistent
with central cholinergic stimulation. Hemodynamic studies in the rat
demonstrated a 16-fold separation between behaviorally active doses
(1.25 mg/kg) and those that elevated arterial pressure (20 mg/kg).
Lethality in rats occurred at an oral dose of 80 mg/kg, but not at lower
doses. Chemically, P10358 is an N-aminoindole and may not have the
hepatotoxic liability associated with aminoacridine structure of
tacrine. P10358 had weak affinity (\>10 microM) at a variety of
aminergic and peptidergic receptors and uptake carriers. These
properties suggest that P10358 may be a safe and promising symptomatic
treatment for Alzheimer\'s disease.

578\. Sobow, T.M. and I. Kloszewska, *\[Risperidone in the ambulatory
treatment of behavior disorders in demented patients of Alzheimer\'s
type: a retrospective analysis\].* Psychiatr Pol, 2001. 35(6): p.
1033-45. Behavioural disturbances are common in the course of dementia
in Alzheimer\'s disease (AD) and their treatment is usually difficult.
Different pharmacological and non-pharmacological options are employed
basing mainly on clinical experience, still the number of well-designed,
controlled studies in the field is very small. Novel, atypical
neuroleptics, including risperidone might potentially be one of these
options, taking into account their good safety profile and clinical
efficacy in closely related syndromes. We present the results of a
retrospective analysis of 57 outpatients with behavioural symptoms
complicating AD treated with risperidone, either alone or in combination
with one of the acetylcholinesterase inhibitor (AchEI; donepezil or
rivastigmine). Seventy five percent of patients treated responded to
risperidone with the usual effective dose of 0.5-1 mg/day. The influence
of risperidone treatment on behavioural symptomatology was irrespective
to the use of AchEI and equally well safe in both groups. The clinical
response to the treatment was seen usually within first 2-3 weeks, those
who did not respond early tended not to respond later on as well.
Additionally, if not responding to low doses of risperidone (0.5-1
mg/day), patients usually did not respond to higher doses or could not
tolerate them, mainly due to emerging extrapyramidal symptoms (EPS). Low
doses of risperidone were well tolerated, with the fraction of patients
experiencing EPS not achieving 10%. EPS observed, were dose dependent
and tended to appear if the dose acceleration was fast. We then
recommend low doses of risperidone and its slow titration if needed.

579\. Soininen, H., *et al.*, *Dopamine-beta-hydroxylase and
acetylcholinesterase activities of cerebrospinal fluid in Alzheimer\'s
disease.* Acta Neurol Scand, 1984. 70(1): p. 29-34. Recent neurochemical
studies have indicated that in Alzheimer\'s disease there is disturbance
of the cholinergic metabolism of the brain. Defects in other transmitter
systems have also been suggested. As a marker of noradrenergic
metabolism of the central nervous system, we measured
dopamine-beta-hydroxylase (EC. 1.14.17.1) activity in cerebrospinal
fluid (CSF) from 60 Alzheimer patients and 20 controls of the same age
and sex. Dopamine-beta-hydroxylase activities of the CSF from Alzheimer
patients did not differ significantly from those for the controls. The
dopamine-beta-hydroxylase activities were not correlated with severity
of dementia. As reported previously, the activity of a cholinergic
marker, acetylcholinesterase (EC 3.1.1.7), was reduced in the CSF of
Alzheimer patients. Interestingly, dopamine-beta-hydroxylase activities
were correlated with acetylcholinesterase activities both in Alzheimer
patients and control group.

580\. Spencer, C.M. and S. Noble, *Rivastigmine. A review of its use in
Alzheimer\'s disease.* Drugs Aging, 1998. 13(5): p. 391-411.
Rivastigmine (SDZ ENA 713) is a carbamylating, long-acting reversible
and noncompetitive carbamate acetylcholinesterase inhibitor that is
indicated as an oral treatment for patients with mild to moderately
severe Alzheimer\'s disease. The drug has been evaluated for this use in
3 well designed, adequately powered, phase II/III, 26-week clinical
trials that included a total of 1479 rivastigmine and 647 placebo
recipients. Most of these patients had concomitant disorders that were
being treated with numerous other drugs. Individual and pooled results
of these trials indicate that rivastigmine 6 to 12 mg/day usually
produces cognitive, global and functional changes that indicate
significantly less deterioration than was observed with placebo in
patients with mild to moderately severe Alzheimer\'s disease. Individual
results of the 2 pivotal trials and pooled analysis also show that,
compared with placebo recipients, significantly more rivastigmine 6 to
12 mg/day recipients respond to therapy. Indeed, after 26 weeks of
therapy in the 2 pivotal trials, significantly more rivastigmine 6 to 12
mg/day than placebo recipients achieved clinically meaningful
improvements as defined by 3 separate response criteria. The lower
dosage range of 1 to 4 mg/day was not as effective as 6 to 12 mg/day, as
measured using these criteria and other efficacy parameters.
Rivastigmine causes adverse events that are generally those expected
from an acetylcholinesterase inhibitor. They are usually mild to
moderate, of short duration and responsive to dosage reduction.
Unpublished data from 3989 patients indicate that rivastigmine and
placebo were associated with similar incidences of serious adverse
events and changes in laboratory parameters, ECG and cardiorespiratory
vital signs. The most common events were gastrointestinal, central and
peripheral nervous system and whole body adverse events. However,
compared with placebo, rivastigmine more commonly caused adverse events
resulting in treatment withdrawal. These events were most frequently
gastrointestinal and were more common in women. CONCLUSION: Rivastigmine
is a useful option for the treatment of patients with mild to moderately
severe Alzheimer\'s disease. Although only short term (6- month)
comparisons with placebo are available, given the lack of established
treatment options it should be considered for first-line use in this
population.

581\. Sramek, J.J., *et al.*, *Safety/tolerability trial of SDZ ENA 713
in patients with probable Alzheimer\'s disease.* Life Sci, 1996. 58(15):
p. 1201-7. SDZ ENA 713 (ENA 713) is an acetylcholinesterase inhibitor
being developed as a potential treatment for Alzheimer\'s disease (AD).
A prior Phase II safety and efficacy study used an upper dose limit of 6
mg/day ENA 713. The present study was designed to assess the safety and
tolerability of higher doses of ENA 713 in probable AD patients. Fifty
AD patients (22M; 28F, mean age 68 yrs, range 45-90) were assigned to a
fixed, nine-week dose escalation schedule in which they were randomized
to receive up to 12 mg/day of ENA 713 bid (n=20) or tid (n=20), or
placebo (n=10) followed by a one-week washout. Mg/day dose escalation
for the bid and tid ENA 713 groups was identical, beginning with 2
mg/day on Days 1 to 3 and escalating to 12 mg/day in Weeks 8 and 9.
Doses through 12 mg/day were well tolerated. Most adverse events were
mild to moderate in severity and of limited duration, most commonly
headache, nausea, dizziness, and diarrhea. Three of forty patients on
ENA 713 discontinued, all due to adverse events. Two experienced nausea
and vomiting; the third experienced an unrelated mild atrial
fibrillation.

582\. Sramek, J.J., *et al.*, *NXX-066 in patients with Alzheimer\'s
disease: a bridging study.* Life Sci, 1999. 64(14): p. 1215-21. Reduced
cholinergic transmission is a key neurotransmitter dysfunction in
Alzheimer\'s Disease (AD). NXX-066, a physostigmine analog and
acetylcholinesterase (AChE) inhibitor, has demonstrated activity in
animal models of memory function, and was well tolerated in healthy
subjects up to a single dose of 64 mg and multiple doses of 60 mg QD for
seven days. Since AChE inhibitors are often tolerated differently in AD
patients than in healthy volunteers, a randomized, placebo-controlled,
double-blind, single-center, inpatient bridging study was conducted to
determine the maximum tolerated dose (MTD) of NXX-066 in the target
patient population. Seven consecutive panels of eight AD patients each
(6 active, 2 placebo) received fixed oral doses of NXX-066 (20, 30, 40,
50, 60, 70, or 80 mg BID) for seven days. Initiation of each subsequent
panel (dose group) was contingent upon the tolerability of lower dose
levels. The MTD was determined to be 70 mg BID when four of six patients
receiving 80 mg BID were prematurely discontinued from the study due to
nausea and/or vomiting, accompanied in some patients by mild to moderate
dizziness, headache, asthenia, and gastric symptoms. Wide variability in
plasma levels of NXX-066 was observed in all dose panels. AChE
inhibition in whole blood correlated with both maximum plasma
concentration and dose; however, AChE inhibition was not predictive of
adverse events. In this study, AD patients tolerated larger daily doses
of NXX-066 on a BID regimen than healthy normal subjects had tolerated
with QD dosing. Further studies are warranted to examine whether
differing tolerability between patients and healthy subjects or the
reduced dosing interval explains these findings.

583\. Sramek, J.J. and N.R. Cutler, *RBC cholinesterase inhibition: a
useful surrogate marker for cholinesterase inhibitor activity in
Alzheimer disease therapy?* Alzheimer Dis Assoc Disord, 2000. 14(4): p.
216-27. Red blood cell (RBC) acetylcholinesterase (AChE) inhibition has
been used as a peripheral surrogate marker for the activity of centrally
acting AChE inhibitors (AChEIs) in the treatment of Alzheimer disease.
As a valid peripheral surrogate marker, RBC AChE inhibition should
reflect the central pharmacodynamic activity of the compound and should
demonstrate a relation with cognitive or global improvement in patients
with Alzheimer disease. As a useful clinical tool, RBC AChE inhibition
should also provide an advantage in dose optimization. However, the
application of surrogate markers in research and clinical use is
controversial (Prentice, 1989; Gotzsche, 1996; Colburn, 1997; De
Gruttola et al., 1997). For instance, surrogate markers that have been
identified or applied inappropriately can lead to erroneous conclusions,
slowing the drug development process (Colburn, 1997). Also, the
validation of surrogate markers for the pharmacodynamic activity of
central nervous system drugs is not always possible because samples of
brain tissue cannot be analyzed in humans. Finally, although validation
of peripheral markers for central nervous system drugs has been
approached via analysis of cerebrospinal fluid (Cutler et al., 1998a),
few markers have been subjected to such rigorous evaluation in clinical
studies. The extent to which measures of peripheral AChE inhibition
accurately model central drug activity and therapeutic effectiveness of
AChEIs, both as individual agents and as a drug class, is the focus of
this review. AChEIs comprise a group of structurally diverse compounds
with a wide range of relative specificities for the various molecular
species of cholinesterase found in plasma, RBCs, and the brain. Studies
of RBC AChE inhibition after administration of AChEIs in animals are of
limited utility because of the differential sensitivity of AChEIs for
human versus animal forms of AChE, the poor correlation between
effective doses in animals and humans, and the lack of standardized
measurements of effectiveness. Although clinical studies of donepezil,
metrifonate, and eptastigmine have suggested the potential use of RBC
AChE inhibition as a predictor of clinical response, the degree of
inhibition yielding maximum cognitive improvements was highly variable
from compound to compound (30-80%). Further, investigators did not prove
a relation between central and peripheral pharmacodynamics or
demonstrate an advantage over dose in the ability of RBC AChE inhibition
to predict clinical response. A study of rivastigmine in patients with
Alzheimer disease revealed that cerebrospinal fluid AChE inhibition
correlated well with cognitive performance, whereas peripheral
inhibition did not. Therefore, RBC cholinesterase inhibition is not a
reliable surrogate marker for the activity of AChEIs as a class of
drugs, and its usefulness as a dose optimization tool for individual
agents has yet to be demonstrated clearly.

584\. Sugimoto, H., *Donepezil hydrochloride: a treatment drug for
Alzheimer\'s disease.* Chem Rec, 2001. 1(1): p. 63-73. The role of the
cholinergic system with respect to cognitive deficits characteristic of
Alzheimer\'s disease (AD) has led to a number of studies focusing on the
development of acetylcholinesterase (AChE) inhibitors as a drug for
treating this disease. The earliest known AChE inhibitors, namely,
physostigmine and tacrine, performed poorly in clinical trials (e.g.,
poor oral activity, brain penetration, and hepatotoxic liability).
Studies were then focused on finding a new type of acetylcholinesterase
inhibitor that would overcome the disadvantages of these two compounds.
Donepezil hydrochloride inaugurates a new class of AChE inhibitors with
longer and more selective action and with manageable adverse effects.

585\. Summers, W.K., K.H. Tachiki, and A. Kling, *Tacrine in the
treatment of Alzheimer\'s disease. A clinical update and recent
pharmacologic studies.* Eur Neurol, 1989. 29 Suppl 3: p. 28-32. The
initial report of the effectiveness of tacrine or
tetrahydroaminoacridine (THA) in the treatment of some patients with
Alzheimer\'s disease has been confirmed by further study of additional
subjects and by preliminary reports from other investigators. The major
side effect, elevation of liver enzymes, is shown to be reversible,
dose-dependent and without significant hepatic pathology. Therapeutic
serum concentrations of THA vary between 7 and 20 ng/ml. In addition to
its presumed action as an acetylcholinesterase inhibitor, data are
presented demonstrating marked effects on other brain neurotransmitters
in animal models.

586\. Suwata, J., *et al.*, *New acetylcholinesterase inhibitor
(donepezil) treatment for Alzheimer\'s disease in a chronic dialysis
patient.* Nephron, 2002. 91(2): p. 330-2. The new-generation
acetylcholinesterase inhibitor, donepezil, is useful in the treatment of
mild-to-moderate Alzheimer\'s disease. A 72-year-old male chronic
hemodialysis patient was diagnosed as having moderate Alzheimer\'s
disease. We administered donepezil at 3 mg/day orally to the patient.
After 1 month\'s treatment, the patient improved to a controllable
psychiatric condition and was discharged from the hospital. The 24-hour
plasma concentration profile of donepezil following the 3-mg once-daily
dose varied from 11.1 to 18.2 ng/ml. The through level of donepezil was
reduced from 12.4 to 10.9 ng/ml over a 3-month period. We did not
experience any episodes of drug toxicity or adverse effects in this
chronic dialysis patient. Donepezil treatment might have a beneficial
impact on patients with severe renal dysfunction.

587\. Swanwick, G.R. and B.A. Lawlor, *Initiating and monitoring
cholinesterase inhibitor treatment for Alzheimer\'s disease.* Int J
Geriatr Psychiatry, 1999. 14(4): p. 244-8. The availability of
acetylcholinesterase inhibitors for the treatment of Alzheimer\'s
disease raises a number of clinical and ethical questions. Many of the
guidelines published in an attempt to tackle these questions lack either
clinical or scientific validity. Against this background a model is
proposed whereby specialist monitoring using formal tests is neither
appropriate nor necessary to determine whether an individual patient
should continue or stop treatment. Instead the primary care physician
should refer potentially suitable patients for specialist assessment to
confirm the diagnosis/He/she should then initiate, monitor, and
discontinue treatment based on the establishment of realistic treatment
goals agreed with the patient/carer at the outset.

588\. Taylor, P., *Development of acetylcholinesterase inhibitors in the
therapy of Alzheimer\'s disease.* Neurology, 1998. 51(1 Suppl 1): p.
S30-5; discussion S65-7. Acetylcholinesterase (AChE) inhibitors were
first administered in Europe to human subjects in the 1860s, and
synthetic derivatives of the natural alkaloid inhibitors were developed
in the 1930s to modulate peripheral cholinergic function. However, only
within the last decade have these agents been systematically studied for
therapy of central cholinergic deficits. This time interval parallels
the cloning of the gene and determination of the structure of the target
molecule, AChE. Because AChE in mammals is encoded by a single gene and
the portion of the gene encoding the catalytic domain is invariant,
selectivity of action can be achieved only by altering parameters of
disposition and pharmacokinetics of action of the inhibitor rather than
its specificity for particular AChE isozymes in various regions of the
CNS. This article describes the mechanism of action of short-acting,
carbamoylating, and phosphorylating inhibitors of cholinesterase and
suggests possible strategies for enhancing therapeutic efficacy.

589\. Trabace, L., *et al.*, *Biochemical and neurobehavioral profile of
CHF2819, a novel, orally active acetylcholinesterase inhibitor for
Alzheimer\'s disease.* J Pharmacol Exp Ther, 2000. 294(1): p. 187-94.
1,2,3,3a,8,8a-Hexahydro-1,3a,8-trimethylpyrrolo inverted question
mark2,3-bindol-5-ol 2-ethylphenylcarbamate N-oxide hydrochloride
(3aS-cis) (CHF2819) is a novel acetylcholinesterase inhibitor that
produces central cholinergic stimulation after oral administration in
rats. In vivo studies show that CHF2819 (0.5, 1.5, and 4.5 mg/kg p.o.)
significantly increases acetylcholine levels in young adult rat
hippocampus in a dose-dependent manner. Moreover, aged animals, which
show a significant decrease in basal acetylcholine levels with respect
to young adult rats, also exhibit a marked increase in the hippocampal
concentrations of this neurotransmitter after the administration of
CHF2819. This compound (1.5 mg/kg p.o.) significantly attenuates
scopolamine-induced amnesia in a passive avoidance task. Furthermore,
CHF2819 induces a significant decrease in dopamine levels and a
significant elevation of extracellular concentrations of
5-hydroxytryptamine, whereas it does not modify norepinephrine and
gamma-aminobutyric acid levels in the hippocampus of young adult rats.
Functional observational battery screening demonstrates that CHF2819
(1.5 and 4.5 mg/kg p.o.) does not affect activity, excitability,
autonomic, neuromuscular, and sensorimotor domains, as well as
physiological end points (body weight and temperature). However, this
compound induces involuntary motor movements (ranging from mild tremors
to myoclonic jerks) in a dose-dependent manner. These findings suggest
that the anti-amnestic properties of CHF2819, together with its
stimulatory effect on cholinergic and serotonergic functions, might have
a therapeutic potential mainly for the symptomatic treatment of
Alzheimer\'s disease patients in which the cognitive impairment is
accompanied by a depressive syndrome.

590\. Unni, L., *et al.*, *The recovery of cerebrospinal fluid
acetylcholinesterase activity in Alzheimer\'s disease patients after
treatment with metrifonate.* Methods Find Exp Clin Pharmacol, 2000.
22(1): p. 57-61. We investigated the relationship between peripheral and
central cholinesterase (ChE) inhibition levels after chronic treatment
of Alzheimer\'s disease (AD) patients with metrifonate (MTF). In a
6-month, double-blind, placebo-controlled trial in AD patients treated
with a weekly 2.9 mg/kg MTF dose, we observed 17.15 +/- 23.43, 66.92 +/-
7.30 and 60.80 +/- 12.20% inhibition (n = 6) of cerebrospinal fluid
(CSF) and red blood cell (RBC) acetylcholinesterase (AChE) and plasma
butyrylcholinesterase (BuChE), respectively. In another study, AD
patients were treated with daily MTF to achieve RBC AChE inhibition
levels of 85.90%. The CSF AChE inhibition was 67.93 +/- 13.69% (n = 3)
at 3-4 h after the last treatment and 6.62 +/- 9.36% (n = 2) at 8 days
after dosing. The recovery half time of CSF AChE was 2.21 +/- 1.22 days.
These data show that CSF AChE recovers faster than the peripheral plasma
and RBC enzymes. Under conditions of chronic weekly dosing with MTF, RBC
AChE inhibition does not reflect CSF, and arguably, brain AChE
inhibition. Our data do not support continuous central neuronal AChE
inhibition as the mechanism for the long-term efficacy of metrifonate
for the treatment of AD.

591\. Vida, S., L. Gauthier, and S. Gauthier, *Canadian collaborative
study of tetrahydroaminoacridine (THA) and lecithin treatment of
Alzheimer\'s disease: effect on mood.* Can J Psychiatry, 1989. 34(3): p.
165-70. Several lines of evidence have implicated acetylcholine (ACh) as
one of the neurotransmitters found to be decreased in Alzheimer\'s
disease (AD). Various methods of cholinergic augmentation have been
attempted, with mixed results. Tetrahydroaminoacridine (THA), an
acetylcholinesterase inhibitor, is currently being investigated at the
McGill Centre for Studies in Aging. Preliminary uncontrolled data from a
10-week clinical trial of THA and lecithin, reported elsewhere, suggest
a clinically modest but statistically significant beneficial effect on
cognition, although problems exist with side effects, particularly
gastrointestinal. Since the suggestion by Janowsky in 1972 that
cholinergic neurotransmission may exert an inhibitory or depressant
effect on mood, the evidence accumulated in the literature has been
inconclusive. We undertook to assess several potential pretreatment
correlates of depressive symptoms in AD and to monitor the course of
these symptoms during the 10 week treatment period, using the Geriatric
Depression Scale (GDS) of Brink and Yesavage. Pretreatment GDS scores
were found to correlate with degree of overall disability and dementia
as measured by the Rapid Disability Rating Scale (RDRS) and the Mini
Mental State Examination (MMS), respectively. GDS scores over the
treatment period did not change to a statistically significant degree.
The meaning of these results is discussed, particularly with reference
to the difficulty of diagnosis and measurement of depression in the
setting of dementia.

592\. Wang, H., *et al.*, *Effects of bis(7)-tacrine, a novel
anti-Alzheimer\'s agent, on rat brain AChE.* Neuroreport, 1999. 10(4):
p. 789-93. The anticholinesterase effects of bis(7)-tacrine were
compared with tacrine in vitro and in vivo. Based on IC50 ratios, the
dimeric analog bis(7)-tacrine was, in a reversible manner, up to
150-fold more potent and 250-fold more selective than tacrine for
acetylcholinesterase (AChE) over butyrylcholinesterase (BChE). Following
a single oral administration, both bis(7)-tacrine and tacrine produced
dose-dependent inhibitions of AChE in rat brain, but bis(7)-tacrine
exhibited higher efficacy and AChE/BChE selectivity than tacrine. The
anti-AChE efficacy of bis(7)-tacrine was quite similar following an oral
or i.p. administration, but tacrine showed much lower efficacy when
administered orally than when given i.p. These findings suggest
bis(7)-tacrine, a highly potent and selective inhibitor of AChE, can
probably be used as an improved drug in the palliative treatment of AD.

593\. Weinstock, M., *The pharmacotherapy of Alzheimer\'s disease based
on the cholinergic hypothesis: an update.* Neurodegeneration, 1995.
4(4): p. 349-56. Alzheimer\'s disease (AD) is a neurodegenerative
disorder with impairment of cognitive function and personality. The
synaptic loss, neuronal atrophy and degeneration of cholinergic nuclei
in the basal forebrain may be associated with a reduction in oxidative
metabolism of glucose, a fall in acetyl CoA and ATP. Current
pharmacological strategies, aimed at increasing cholinergic activity
include acetylcholinesterase (AChE) inhibitors, cholinergic agonists,
acetylcholine (ACh) releasers and stimulants of nerve growth factors
(NGF). AChE inhibitors, physostigmine and Tacrine can slow the decline
of cognitive function and memory in some patients with mild or moderate
AD, if given for at least 3-6 months in sufficient doses to inhibit
brain AChE. Their main disadvantages are low oral bioavailability,
peripheral cholinergic hyperactivity and liver toxicity with Tacrine.
Newer, less toxic AChE inhibitors, with selective central activity,
formulations of physostigmine, selective Ml and nicotinic agonists are
becoming available with improved bioavailability and pharmacokinetics.
These may increase the likelihood of therapeutic benefit in AD.
Nootropic drugs, e.g. piracetam, which release ACh and are relatively
non-toxic could possibly slow the progression of the disease. A
combination of an AChE inhibitor, piracetam and a stimulator of NGF may
show additive effects on memory processes but with a lower incidence of
untoward effects.

594\. Weinstock, M., *et al.*, *TV3326, a novel neuroprotective drug
with cholinesterase and monoamine oxidase inhibitory activities for the
treatment of Alzheimer\'s disease.* J Neural Transm Suppl, 2000(60): p.
157-69. TV3326, \[(N-propargyl-(3R) aminoindan-5-yl)-ethyl methyl
carbamate\] is a novel aminoindan derivative of the selective
irreversible monoamine oxidase (MAO)-B inhibitor, rasagiline
(N-propargyl-(1R)-aminoindan), possessing both cholinesterase (ChE) and
MAO-inhibitory activity. In doses of 35-100 micromoles/kg administered
orally to rats, it inhibits ChE by 25-40% and antagonises
scopolamine-induced impairments in spatial memory. After daily
administration of 75 micromoles/kg for 2 weeks, TV3326 does not show any
motor stimulant effects but significantly reduces immobility in the
forced swim test, an action consistent with that of known
antidepressants. This could result from more than 70% inhibition of both
MAO-A and B in the brain that occurs under these conditions, since it is
not shared by the S-isomer, TV3279, which does not block MAO. TV3326
also shows selectivity for brain MAO, even after 2 months of daily
administration, with little or no effect on the enzyme in the intestinal
tract and liver. This reduces the likelihood of it producing the
\"cheese effect\" if administered with tyramine-containing foods or
beverages. TV3326 and TV3279 protect against ischemia-induced
cytotoxicity in PC12 cells and reduce the oedema, deficits in motor
function and memory after closed head injury in mice. These
neuroprotective effects do not result from MAO inhibition. The
pharmacological actions of TV3326 could be of clinical importance for
the treatment of AD, and the drug is currently in development for this
purpose.

595\. Wilkinson, D.G., *The pharmacology of donepezil: a new treatment
of Alzheimer\'s disease.* Expert Opin Pharmacother, 1999. 1(1): p.
121-35. Donepezil (donepezil hydrochloride, E-2020, Aricept, Eisai),
launched in March 1997, was the first drug to be marketed for the
symptomatic treatment of Alzheimer\'s disease (AD) in the UK. It had
been launched a year earlier in the US where clinicians had already had
experience of tacrine (THA). Donepezil is a piperidine based, potent,
specific, non-competitive and reversible inhibitor of
acetylcholinesterase (AChE). It is structurally dissimilar from other
established cholinesterase inhibitors, namely THA (an acridine compound)
and the carbamates, physostigmine and rivastigmine and has a
pharmacokinetic and tolerability profile distinct from these agents.
Experimentally, donepezil inhibits AChE activity in human erythrocytes
and increases extracellular acetylcholine levels in the cerebral cortex
and the hippocampus of the rat. Pharmacologically, donepezil has a
half-life of approximately 70 h lending itself to once daily
administration. The most common adverse events reported in clinical
trials have been gastrointestinal, typically nausea, vomiting, diarrhoea
and constipation. Headache, dizziness and sleep disturbance have also
been reported; there has been no evidence of hepatotoxicity. Clinically
a number of placebo-controlled trials have shown that donepezil 5 or 10
mg daily was associated with significant improvements in cognitive
function, as assessed by the Alzheimer\'s disease Assessment
Scale-cognitive subscale (ADAS cog) after 12 or 24 weeks treatment.
Significant improvements in global function and activities of daily
living have also been demonstrated after 24 weeks treatment compared
with placebo in patients with mild to moderate AD. Donepezil was the
first rational treatment available in the UK for this disabling
condition and as such received considerable attention. Much of the
original attention was negative, ostensibly based on the scientific view
that there was not enough published evidence to justify widespread use,
but this was driven by concerns about the potentially high drug costs if
all patients with AD were eligible to receive it. Considerable data have
now been produced from Phase II, III and post-marketing surveillance.
This drug evaluation will review the basic pharmacology of donepezil and
place it in context with the trial data and the author\'s clinical
experience with the drug.

596\. Wilkinson, D. and J. Murray, *Galantamine: a randomized,
double-blind, dose comparison in patients with Alzheimer\'s disease.*
Int J Geriatr Psychiatry, 2001. 16(9): p. 852-7. OBJECTIVES: To
investigate whether Galantamine significantly improves the core symptoms
of Alzheimer\'s disease (AD). BACKGROUND: Galantamine is a reversible,
competitive, selective inhibitor of acetylcholinesterase (AChE) that
also allosterically modulates nicotinic acetylcholine receptors. This
dual mechanism of action provided the rationale for a phase II trial of
galantamine in AD. METHOD: A multicentre, randomized, parallel,
double-blind, placebo-controlled trial was carried out to evaluate the
efficacy and tolerability of galantamine 18, 24 and 36 mg/day
administered for 3 months in 285 patients with mild-to-moderate probable
AD. The primary outcome measure was the Alzheimer\'s Disease Assessment
Scale cognitive subscale (ADAS-cog); secondary outcome measures were the
Clinical Global Impression of Change (CGIC) and the Progressive
Deterioration Scale (PDS). RESULTS: Patients treated with galantamine 24
mg/day had a significantly better outcome than placebo on ADAS-cog; the
treatment difference was 3 points on the intention-to-treat (ITT)
analysis ( p = 0.01) and 4.2 points on per protocol analysis ( p =
0.001). Per protocol analysis showed that galantamine had a
significantly better outcome than placebo on PDS ( 24-mg/day dose, p \<
0.05) and CGIC (36-mg/day dose, p \< 0.05). Galantamine was well
tolerated at the lower doses of 18 and 24 mg/day where it produced mild,
transient effects typical of cholinomimetic agents. CONCLUSION: This
study shows that, relative to placebo, galantamine significantly
improves the core symptoms of Alzheimer\'s disease.

597\. Woo, J.K. and M.S. Lantz, *Alzheimer\'s disease: how to give and
monitor tacrine therapy.* Geriatrics, 1995. 50(5): p. 50-3. Up to
one-third of patients with mild to moderate Alzheimer\'s disease may
show improvement in cognitive function with tacrine, a centrally-acting,
noncompetitive inhibitor of acetylcholinesterase. Candidates for tacrine
must have a diagnosis of probable Alzheimer\'s dementia based on
NINCDS-ADRDA or DSM-IV criteria and should have no history of liver
disease. For patients receiving the drug, do follow-up cognitive testing
with a sensitive measure such as the Alzheimer\'s Disease Assessment
Scale. The most common adverse effects associated with tacrine therapy
are elevated liver transaminases and gastrointestinal effects. Weekly
blood tests are necessary to monitor liver function. A reliable
caregiver is essential to ensure compliance with frequent dosing and
weekly blood testing.

598\. Xiao, X.Q., *et al.*, *Bis(7)-tacrine, a promising
anti-Alzheimer\'s agent, reduces hydrogen peroxide-induced injury in rat
pheochromocytoma cells: comparison with tacrine.* Neurosci Lett, 2000.
290(3): p. 197-200. The present study investigates the effects of
bis(7)-tacrine, a novel dimeric acetylcholinesterase inhibitor, on
hydrogen peroxide(H(2)O(2))-induced cell injury with comparison to the
corresponding monomer, tacrine. Exposure of rat pheochromocytoma line
PC12 cells to H(2)O(2) induced significant cell damage. This reagent
also caused redox desequilibrium as indicated by a decrease in
activities of intracellular antioxidant enzymes such as glutathione
peroxidase as well as catalase and an accumulation of malondialdehyde, a
product of lipid peroxidation. Pretreatment of cells with bis(7)-tacrine
or tacrine attenuated H(2)O(2)-induced cell toxicity, and bis(7)-tacrine
demonstrated higher potency than tacrine in improving redox
desequilibrium. These results suggest that bis(7)-tacrine and tacrine
significantly protect against H(2)O(2) insult, which might be beneficial
for their potential usage in the prevention and treatment of
Alzheimer\'s disease.

599\. Xu, M., *et al.*, *Determination of basal acetylcholine release in
vivo by rat brain dialysis with a U-shaped cannula: effect of SM-10888,
a putative therapeutic drug for Alzheimer\'s disease.* Neurosci Lett,
1991. 123(2): p. 179-82. A U-shaped dialysis cannula was implanted into
rat frontal cortex, hippocampus and striatum, and after 1 day for
surgical recovery the cannula was perfused with Ringer\'s solution
without any acetylcholinesterase (AChE) inhibitor under freely moving
conditions. With a highly sensitive assay method for acetylcholine
(ACh), the basal ACh content in the dialysates were detectable in those
brain regions for several hours. The basal levels in the frontal cortex,
hippocampus and striatum were 82 +/- 9, 72 +/- 4, 70 +/- 8 fmol/20
microliters (mean +/- S.E.M.), respectively. When SM-10888, a novel AChE
inhibitor and putative therapeutic drug for Alzheimer\'s disease, was
injected intraperitoneally, ACh in the dialysate of the cortex increased
in a dose-dependent manner. Changes in the levels of hippocampal and
striatal ACh release evoked by SM-10888 were similar to, but smaller
than, that in the cortex. These data suggest that since the present
assay method is able to determine in vivo basal ACh release in the
dialysate without any AChE inhibitor, it is possible to study the effect
of a novel drug such as SM-10888 in the brain regions.

600\. Yu, Q., *et al.*, *Synthesis of novel phenserine-based-selective
inhibitors of butyrylcholinesterase for Alzheimer\'s disease.* J Med
Chem, 1999. 42(10): p. 1855-61. Four novel analogues (8-11) of cymserine
(2) were synthesized by methods similar to those recently developed for
the total syntheses of N8-norphenserine (Yu, Q. S.; et al. J. Med. Chem.
1997, 40, 2895-2901) and N1,N8-bisnorphenserine (Yu, Q. S.; et al. J.
Med. Chem. 1998, 41, 2371-2379). As our structure-activity studies
predicted, these compounds are highly potent and selective inhibitors of
human butyrylcholinesterase (BChE) and will test the novel hypothesis
that BChE inhibitors are useful in the treatment of Alzheimer\'s
disease. In a similar manner, the same modifications that provided BChE
selectivity were applied to the acetylcholinesterase (AChE)-selective
inhibitor, tolserine (5), to provide the novel tolserine analogues
12-15. As predicted, these modifications altered the AChE-selective
action of tolserine (5) to favor a lack of cholinesterase enzyme subtype
selectivity.

601\. Zhang, W., B.R. Johnson, and T.D. Bjornsson, *Pharmacologic
inhibition of transglutaminase-induced cross-linking of Alzheimer\'s
amyloid beta-peptide.* Life Sci, 1997. 60(25): p. 2323-32. The brain of
Alzheimer\'s disease (AD) patients contains deposits of amyloid
beta-peptide (A beta). Recent studies have shown that A beta is a
substrate for tissue transglutaminase (TGase), which induces the
formation of cross-linked dimers and polymers, and that tacrine,
indomethacin and deferoxamine, which have widely different chemical
structures, attenuate the progression of symptoms of AD. This report
evaluated the potential of a total of ten different pharmacological
agents to inhibit TGase-induced cross-linking of A beta, including known
TGase inhibitors (dansylcadaverine, spermine), non-steroidal
anti-inflammatory drugs (indomethacin, meclofenamic acid, diflunisal,
salicylic acid), monoamine oxidase inhibitors (tranylcypromine,
phenelzine), an acetylcholinesterase inhibitor (tacrine), and an iron
chelating agent (deferoxamine). All but one (salicylic acid) of these
ten agents had an inhibitory effect on TGase-induced A beta
cross-linking. These results suggest that inhibition of TGase-induced
cross-linking of A beta is a potential pharmacologic target for the
treatment of AD. A method is also presented for the determination of
percent inhibition of TGase-induced A beta cross-linking based on the
separated monomer, dimer and polymer bands on SDS-PAGE gels.

602\. Asthana, S., *et al.*, *Treatment of Alzheimer disease by
continuous intravenous infusion of physostigmine.* Alzheimer Dis Assoc
Disord, 1995. 9(4): p. 223-32. Physostigmine, a reversible and
nonselective cholinesterase inhibitor, administered by steady-state,
continuous intravenous infusion to carefully selected subjects with
mild-moderate Alzheimer disease, produced significant but modest
improvement in memory in five of nine subjects. Drug dosing was limited
by the occurrence of adverse effects. Apparent tolerance to adverse
effects was observed in two subjects when the dose of physostigmine was
escalated slowly over at least 2 weeks. Steady-state cholinesterase
inhibition by physostigmine appears to produce sustained cognitive
improvement in some subjects with Alzheimer disease without
substantially altering its therapeutic index.

603\. Asthana, S., *et al.*, *Neuroendocrine responses to intravenous
infusion of physostigmine in patients with Alzheimer disease.* Alzheimer
Dis Assoc Disord, 1999. 13(2): p. 102-8. We have reported that
physostigmine, a reversible cholinesterase inhibitor, enhances verbal
memory in patients with Alzheimer disease (AD). To elucidate the
mechanism of cognition enhancement, plasma hormones were measured during
high-dose acute and low-dose chronic steady-state intravenous infusions
of physostigmine in nine subjects with AD. High-dose hormone responses
were measured during and for 24 h after the infusion of physostigmine
1-1.5 mg over 45-60 min. Chronic responses were measured during
continuous intravenous infusions of physostigmine at doses (0.5-25
mg/day) that escalated over 2 weeks, and then during 1 week infusion of
the dose that optimized cognition (2-12 mg/day) or placebo administered
in a randomized, double-blind, cross-over design. A replicable
improvement in verbal memory was found in five subjects. High-dose
physostigmine infusion that produced noxious side effects resulted in
significant elevation above baseline in plasma levels of
adrenocorticotrophic hormone (ACTH) (p = 0.0001), cortisol (p = 0.0001),
and beta-endorphin (p = 0.0001). Chronic physostigmine administration,
in the absence of adverse effects, produced no significant elevation in
ACTH (p = 0.08), cortisol (p = 0.70), or beta-endorphin (p = 0.82).
These results indicate that high-dose physostigmine activates the
hypothalamic-pituitary-adrenal (HPA) axis, likely representing a
\"stress response.\" In contrast, cognition-enhancing doses do not
produce a peripheral corticosteroid response. Thus,
physostigmine-induced memory improvement is independent of the
activation of the HPA axis.

604\. Beach, T.G., *et al.*, *Reduction of cortical amyloid beta levels
in guinea pig brain after systemic administration of physostigmine.*
Neurosci Lett, 2001. 310(1): p. 21-4. Overproduction of the peptide
amyloid beta (Abeta) is thought to be a critical pathogenetic event in
Alzheimer\'s disease (AD). Decreasing A production may therefore slow or
halt the progression of AD. In vitro work has indicated that cholinergic
muscarinic receptor agonists may reduce cellular production of Abeta.
Here we show that systemic administration of physostigmine, an
acetylcholinesterase inhibitor, lowers Abeta levels in vivo. Guinea pigs
treated for 10 days with s.c. physostigmine had levels of cortical
AbetaN-40 and N-42 which were 57% and 72%, respectively, of those in
control animals. Levels of cortical beta-amyloid precursor protein were
not significantly affected by drug treatment. These results suggest that
cholinergic therapy may affect the course of AD by limiting Abeta
accumulation.

605\. Becker, R., *et al.*, *Potential pharmacotherapy of Alzheimer
disease. A comparison of various forms of physostigmine administration.*
Acta Neurol Scand Suppl, 1988. 116: p. 19-32. This paper reviews
clinical trials with physostigmine administered to Alzheimer patients
using three different routes of administration: oral, i.v. and
intracerebroventricular (i.c.v.). It compares results obtained with
three different routes by the authors as well as by other authors.
Particular emphasis is given to a novel type of physostigmine
administration, the i.c.v. route. Advantages and disadvantages, as well
as side effects of each route are presented and discussed.

606\. Beller, S.A., J.E. Overall, and A.C. Swann, *Efficacy of oral
physostigmine in primary degenerative dementia. A double-blind study of
response to different dose level.* Psychopharmacology (Berl), 1985.
87(2): p. 147-51. To examine the efficacy of cholinergic enhancement in
senile dementia of the Alzheimer type (SDAT), oral physostigmine was
given to eight patients in a cross-over trial of three dose levels and a
matching placebo. A dose-related improvement in memory as measured by
objective verbal memory tests was observed. Performance was
significantly better on the highest dose, 2 mg every 2 h, than on the
lower doses. The effect was most systematically present for very
short-term memory, which raises the question of whether the improvement
may involve attention rather than longer term storage and retrieval.

607\. Beller, S.A., *et al.*, *Long-term outpatient treatment of senile
dementia with oral physostigmine.* J Clin Psychiatry, 1988. 49(10): p.
400-4. The authors describe five patients with senile dementia of the
Alzheimer type (SDAT) who were treated with oral physostigmine from 1 to
3 3/4 years. An abbreviated form of the Buschke selective reminding test
was used to assess the patients\' short-term verbal memory at periodic
clinic visits. Although one of the patients deteriorated progressively
from the start of the physostigmine therapy and was taken off the drug
after 1 year, there was no evidence of deterioration in memory
performance on the average in the other four patients. Equally
important, this open trial provides evidence of the safety of long-term
treatment with physostigmine on an outpatient basis. The authors view
their results as supporting the potential value of cholinesterase
inhibition as a means of forestalling memory decline in SDAT patients.

608\. Bhat, R.V., *et al.*, *Selective changes in sensitivity to
cholinergic agonists and receptor changes elicited by continuous
physostigmine infusion.* J Pharmacol Exp Ther, 1990. 255(1): p. 187-96.
A reduction in nicotinic receptors has been observed in brains of
patients with Alzheimer\'s disease, and physostigmine, an indirect
acting cholinergic agonist, has been suggested as a treatment of this
disease. However, the effects of physostigmine treatment have not been
thoroughly characterized. The central and peripheral effects of
physostigmine were evaluated in C57BL/6 mice using a battery of
behavioral and physiological tests that included respiratory rate, Y
maze crossing and rearing activities, heart rate and body temperature.
With the exception of the heart rate test, which was blocked by a
peripheral muscarinic antagonist, all responses to physostigmine
measured in the test battery seem to be mediated centrally. Sensitivity
to physostigmine and to nicotine and oxotremorine were examined as were
nicotinic and muscarinic receptors after continuous infusion of
physostigmine. Mice (C57BL/6) continuously infused with physostigmine
(0.1 mg/kg/h) for 10 days developed marked tolerance to physostigmine
and exhibited a slight decrease in sensitivity to nicotine; sensitivity
to oxotremorine was largely unaltered. Chronic physostigmine treatment
resulted in a 62% inhibition of AChE activity and elicited a significant
increase in the amount of L-\[3H\] nicotine binding in midbrain,
hippocampus, striatum and colliculi; alpha-\[125I\]bungarotoxin and
\[3H\]quinuclidinyl benzilatl binding were not changed. Although
physostigmine treatment might partially reverse the reduction of brain
nicotinic receptors seen with Alzheimer\'s disease, it is questionable
whether it would be effective for a prolonged period since the
up-regulated nicotinic receptors may not have normal function.

609\. Bierer, L.M., *et al.*, *A pilot study of oral physostigmine plus
yohimbine in patients with Alzheimer disease.* Alzheimer Dis Assoc
Disord, 1993. 7(2): p. 98-104. Effective symptomatic treatment of
Alzheimer\'s disease (AD) may require a combination of agents that
augment cholinergic as well as noradrenergic neurotransmission. We
conducted a pilot study of physostigmine plus oral yohimbine challenge
in AD. Ten patients were enrolled in a 12-day double-blind protocol.
Each patient received placebo q2h while awake for 5 days, followed by
physostigmine 2 mg q2h while awake for 7 days. During each of these drug
conditions, yohimbine challenges were administered at oral doses of 10
and 20 mg in a placebo-controlled manner. There was no significant
improvement in Alzheimer\'s Disease Assessment Scale test performance
for six patients for whom complete cognitive data were obtained for the
6 challenge days. Nine patients tolerated the protocol with no
clinically significant changes in blood pressure, pulse, or
electrocardiogram (ECG), and no cardiovascular, gastrointestinal, or
autonomic toxicity. One patient complained of chest discomfort
associated with tachycardia, a modest rise in blood pressure, and had
t-wave inversion in a single precordial lead. These signs and symptoms
resolved within a few hours. Serial ECG tracings and cardiac enzymes
revealed no evidence of myocardial injury. This pilot study did not
reveal major cognitive improvement with this regimen, but underscores
the importance of careful cardiovascular monitoring during future
combined cholinergic-noradrenergic therapies in AD.

610\. Bierer, L.M., *et al.*, *A pilot study of clonidine plus
physostigmine in Alzheimer\'s disease.* Dementia, 1994. 5(5): p. 243-6.
To assess the feasibility of one approach to combined
cholinergic/noradrenergic treatment in Alzheimer\'s disease, ten
patients were enrolled in a 2-week placebo-controlled study of oral
physostigmine plus clonidine. The Alzheimer\'s Disease Assessment Scale
(ADAS) was used as the primary outcome measure. Neither physostigmine
alone, nor the combination of physostigmine plus clonidine, was
associated with a statistically significant improvement for the group.
Three patients did show an improvement of at least 4 points on the total
ADAS score with the drug combination. The implications of these results
for treatment strategies are discussed.

611\. Blackwood, D.H. and J.E. Christie, *The effects of physostigmine
on memory and auditory P300 in Alzheimer-type dementia.* Biol
Psychiatry, 1986. 21(5-6): p. 557-60. .

612\. Cain, J.W., *Hypertension associated with oral administration of
physostigmine in a patient with Alzheimer\'s disease.* Am J Psychiatry,
1986. 143(7): p. 910-2. The hemodynamic effects of physostigmine, a
cholinomimetic drug used in the experimental treatment of Alzheimer\'s
disease, are largely unknown. The author describes the development of
episodes of hypertension in an elderly patient with Alzheimer\'s disease
following treatment with oral physostigmine.

613\. Caltagirone, C., G. Gainotti, and C. Masullo, *Oral administration
of chronic physostigmine does not improve cognitive or mnesic
performances in Alzheimer\'s presenile dementia.* Int J Neurosci, 1982.
16(3-4): p. 247-9. Physostigmine was administered orally 1 mg q.i.d. for
one month to 8 patients with a clinical diagnosis of Alzheimer\'s
presenile dementia. The possible beneficial effects of the drug were
evaluated by means of a neuropsychological battery administered to all
patients before and after treatment. The performances obtained by
demented patients on retest did not show any difference in comparison
with performances obtained on the first neuropsychologic assessment.
Some implications of these negative results are briefly discussed.

614\. Caltagirone, C., *et al.*, *Acute administration of individual
optimal dose of physostigmine fails to improve mnesic performances in
Alzheimers Presenile Dementia.* Int J Neurosci, 1983. 18(1-2): p. 143-7.
Eight patients affected by Alzheimer\'s Presenile Dementia (AD) received
acute administration of physostigmine individual optimal dose per os (n
= 4) or subcutaneously (n = 4). The individual physostigmine dose was
assessed by means of serum cholinesterase activity monitoring. The
possible beneficial effects after treatment were evaluated by using two
memory tests: Reys\' 15 words and Digit Span from Wechsler memory scale.
Although a slight behavioral activation was noted in all patients after
treatment, the comparison between mean scores obtained by AD patients in
mnesic tests before and after the acute physostigmine administration,
with either therapeutic modality, failed to reach the level of
statistical significance. Some implications of these disappointing
results are briefly discussed.

615\. Christie, J.E., *et al.*, *Physostigmine and arecoline: effects of
intravenous infusions in Alzheimer presenile dementia.* Br J Psychiatry,
1981. 138: p. 46-50. Physostigmine (0.25 mg-1 mg), arecoline (2 and 4
mg) and saline were administered intravenously over 30 minutes in a
randomized double blind design to 11 patients with a clinical diagnosis
of Alzheimer presenile dementia. Significant improvement was seen on a
picture recognition test with physostigmine 0.375 mg and arecholine 4
mg. A trend towards improvement was also seen with physostigmine 0.25 mg
and 0.75 mg, and arecholine 2 mg. For the majority of the patients
improvement was only slight but in two patients it was clear cut and
consistent.

616\. Dahlin, M. and E. Bjork, *Nasal administration of a physostigmine
analogue (NXX-066) for Alzheimer\'s disease to rats.* Int J Pharm, 2001.
212(2): p. 267-74. The nasal route has been receiving attention for the
administration of systemically active drugs because delivery is
convenient, reliable and rapid. The aims of this study were to
investigate the systemic absorption of nasally administered (3aS)-cis-1,
2, 3, 3a, 8, 8a-hexahydro-1, 3a, 8-trimethyl-pyrrolo-\[2,3b\]-indol-5-yl
3, 4 dihydro-2-isoquinolincarboxylate (NXX-066), a physostigmine
analogue, in rats and to compare the uptake of the drug into the
cerebrospinal fluid (CSF) after nasal and intravenous administration.
NXX-066 (3 micromol/kg) was administered to both nostrils or into the
vena jugularis of male Sprague-Dawley rats. Blood and CSF samples were
obtained at regular intervals from the arteria carotis and by cisternal
puncture, respectively. The concentrations of NXX-066 in the blood and
CSF samples were measured using HPLC with fluorescence detection.
NXX-066 was absorbed rapidly after nasal administration with the peak
concentration occurring within 1.5 min. The nasal bioavailability of
NXX-066 was 100+/-30% and the elimination from plasma was as rapid as
that following intravenous administration. Low concentrations of NXX-066
were detected in the CSF after both intravenous and nasal
administration. In conclusion, NXX-066 was rapidly and totally absorbed
into the systemic circulation and uptake into the CSF was not enhanced
by nasal administration in rats.

617\. Davidson, M., *et al.*, *Physostigmine in patients with
Alzheimer\'s disease.* Psychopharmacol Bull, 1986. 22(1): p. 101-5. .

618\. Davidson, M., *et al.*, *Combined administration of physostigmine
and clonidine to patients with dementia of the Alzheimer type: a pilot
safety study.* Alzheimer Dis Assoc Disord, 1989. 3(4): p. 224-7. Reports
of cholinergic and noradrenergic deficits in brain specimens from
Alzheimer patients have suggested that concomitant augmentation of
cholinergic and noradrenergic neurotransmission can benefit some
dementia of the Alzheimer type (DAT) patients. However, pharmacological
agents that enhance central cholinergic and noradrenergic
neurotransmission, like physostigmine and clonidine, might have serious
adverse effects. Therefore, prior to the commitment of major resources
in efficacy studies, feasibility pilot studies are necessary to ensure
that physostigmine and clonidine, combined, can be safely administered
to DAT patients. Physostigmine, 2 mg every 2 h, and clonidine, up to 0.3
mg/day, were tolerated by the nine DAT patients without clinically
meaningful adverse effects.

619\. Davis, K.L., *et al.*, *Physostigmine: improvement of long-term
memory processes in normal humans.* Science, 1978. 201(4352): p. 272-4.
Nineteen normal male subjects received 1.0 milligram of physostigmine or
1.0 milligram of saline by a slow intravenous infusion on two
nonconsecutive days. Physostigmine significantly enhanced storage of
information into long-term memory. Retrieval of information from
long-term memory was also improved. Short-term memory processes were not
significantly altered by physostigmine.

620\. Davis, K.L. and R.C. Mohs, *Enhancement of memory processes in
Alzheimer\'s disease with multiple-dose intravenous physostigmine.* Am J
Psychiatry, 1982. 139(11): p. 1421-4. Physostigmine (.125 mg, .25 mg, or
.50 mg) or placebo was administered intravenously to 10 neuroleptic-free
patients with Alzheimer\'s disease over a 30-minute period. All patients
performed better on a recognition memory task while receiving
physostigmine. When placebo or the dose of physostigmine previously
associated with an improvement in memory was readministered,
physostigmine again enhanced performance on a recognition memory task.
These results indicate that the acute augmentation of cholinergic
activity in some patients with Alzheimer\'s disease can partially
reverse the memory deficit of that disorder and may provide an approach
to the eventual therapy of this condition.

621\. Davis, K.L., *et al.*, *Oral physostigmine in Alzheimer\'s
disease.* Psychopharmacol Bull, 1983. 19(3): p. 451-3. .

622\. De Sarno, P., *et al.*, *The effect of heptyl-physostigmine, a new
cholinesterase inhibitor, on the central cholinergic system of the rat.*
Neurochem Res, 1989. 14(10): p. 971-7. Heptyl-physostigmine (Heptyl-Phy;
MF-201) is a new carbamate derivative of physostigmine (Phy) with
greater lipophilicity and longer inhibitory action on cholinesterase
(ChE) activity than the parent compound. Following single dose
administration of 5 mg/kg heptyl-Phy i.m., maximal whole brain
acetylcholinesterase (AChE) inhibition (82%) if reached at 60 min.
Inhibition of plasma BuChE butyrylcholinesterase (BuChE) remains close
to the steady state level (60%) between 120 and 360 min. At 360 min,
whole brain AChE activity is still 67% inhibited compared to controls.
Inhibition of AChE activity displays brain regional differences which
are more significant at 360 min. At this time point, AChe activity in
cerebellum is only 40% inhibited while frontal cortex and medial septum
are still 80% inhibited. Increases in acetylcholine (ACh) levels also
show regional differences, however, there is no direct relationship
between AChE inhibition and ACh increase. The electrically evoked
\[3H\]ACh release in cortical slices was inhibited only by the highest
concentration of heptyl-Phy tested (10(-4) M). At this concentration ChE
activity was 97% inhibited in vitro. In conclusion, our results
demonstrate that heptyl-Phy compares favorably to other reversible
cholinesterase inhibitors (ChEI), particularly to Phy as far as
producing a more long-lasting inhibition of AChE and a more prolonged
increase of ACh in brain with less severe side effects. Therefore, it
represents an interesting candidate for cholinomimetic therapy of
Alzheimer disease (AD).

623\. Dell\'Antone, P., M. Bragadin, and P. Zatta, *Anticholinesterasic
drugs: tacrine but not physostigmine, accumulates in acidic compartments
of the cells.* Biochim Biophys Acta, 1995. 1270(2-3): p. 137-41. Tacrine
(THA) and physostigmine (PHS) have been used in Alzheimer\'s disease
therapy for their anticholinesterasic activity. Here we show that THA is
taken up in rat lysosomes in an energy-dependent manner, and that it is
also accumulated in acidic compartments of rat thymocytes and
neuroblastoma cells. A concentration of THA less than 1 mM dissipated
the pH gradient (delta pH) in all the above mentioned in vitro systems.
On the contrary higher concentrations of PHS (1-2 mM) were ineffective.
The accumulation of THA in acidic organelles of the cell may be relevant
for the pharmacological action of THA in Alzheimer\'s treatment.

624\. Denber, H.C., *Physostigmine in the treatment of memory disorders:
a case report.* Psychiatr J Univ Ott, 1982. 7(1): p. 8-12. .

625\. Gold, M., *Physostigmine and Alzheimer\'s disease.* Neurology,
1997. 49(2): p. 642-3. .

626\. Gustafson, L., *et al.*, *Intravenous physostigmine treatment of
Alzheimer\'s disease evaluated by psychometric testing, regional
cerebral blood flow (rCBF) measurement, and EEG.* Psychopharmacology
(Berl), 1987. 93(1): p. 31-5. Ten patients with Alzheimer\'s disease
were treated with intravenous infusion of physostigmine for 2 h. The
acute effects on cognitive function, regional cerebral blood flow, and
EEG were compared to placebo (isotonic glucose) using a double-blind
cross-over design. Physostigmine causes a limited improvement of
psychomotor performance and EEG and an increase of blood flow in the
most severely affected cortical areas, predominantly in an early phase
of Alzheimer\'s disease.

627\. Gustafson, L., *Physostigmine and tetrahydroaminoacridine
treatment of Alzheimer\'s disease.* Acta Neurol Scand Suppl, 1993.
149(Rand): p. 39-41. The cholinergic hypothesis of Alzheimer\'s disease
(AD) was tested in two doubleblind crossover studies. Physostigmine
given intravenously to 10 AD patients for two hours caused improvement
of reaction time and EEG and increased regional cerebral blood flow
(rCBF) in the temporoparietal cortex. 17 AD patients (mean age 62.6 +/-
6.8 years) obtained three types of treatment: tetrahydroaminoacridine
(THA), THA + lecithin and placebo in randomized order. Each treatment
period was 6 weeks. The mean THA dose was 104 +/- 20 mg/day. There were
differences in outcome between groups of patients over the total 26
weeks treatment period. The subclassification in responders, unchanged
and deteriorated was supported by rCBF, EEG and psychometric testing.

628\. Hallak, M. and E. Giacobini, *Physostigmine, tacrine and
metrifonate: the effect of multiple doses on acetylcholine metabolism in
rat brain.* Neuropharmacology, 1989. 28(3): p. 199-206. The effects of
two consecutive intramuscular doses of three cholinesterase inhibitors
(physostigmine, tetrahydroaminoacridine and metrifonate) were compared
in rats. The results revealed major differences in biochemical effects
on the brain of the rat including the extent and duration of inhibition
of cholinesterase, inhibition of release of acetylcholine and increase
in levels of acetylcholine. Side effects were also markedly different in
the time of appearance, duration and severity. These results suggest
that there are significant differences in the mechanisms of action of
various cholinesterase inhibitors. Since all three cholinesterase
inhibitors are currently used in the experimental treatment of
Alzheimer\'s disease, these findings have potential implications for the
symptomatic therapy of these patients.

629\. Harrell, L.E., *et al.*, *The effect of long-term physostigmine
administration in Alzheimer\'s disease.* Neurology, 1990. 40(9): p.
1350-4. We assessed the effect of chronic long-term physostigmine in 20
patients with probable Alzheimer\'s disease. Initially, all patients
went through a dose-finding phase and a double-blind crossover period,
and were subsequently classified as physostigmine responders or
nonresponders based on an a priori classification system. We then
offered all patients long-term treatment with physostigmine regardless
of their initial classification. Results revealed that responders spent
significantly (p less than 0.0005) longer time periods on drug (36.1 +/-
4.6 months) than nonresponders (10.8 +/- 3.2). During a 2nd crossover
period, 18 months into treatment, responders still demonstrated
behavioral improvement, as assessed with the Sandoz Clinical
Assessment-Geriatric Scale, whereas there were no behavioral changes
observed in nonresponders. There were no effects on formal
neuropsychological assessment. The results suggest that a subgroup of
Alzheimer\'s patients benefits from long-term physostigmine therapy.

630\. Harrell, L.E., *et al.*, *Biological and neuropsychological
characterization of physostigmine responders and nonresponders in
Alzheimer\'s disease.* J Am Geriatr Soc, 1990. 38(2): p. 113-22. To
assess the efficacy of oral physostigmine for the treatment of
Alzheimer\'s disease, 20 patients were entered into a clinical trial.
All patients underwent a dose-finding phase (two weeks), followed by an
open trial (two weeks), and a double-blind crossover phase (two weeks
drug, two weeks placebo). Extensive neuropsychological testing (Buschke
Selective Reminding procedure, category generation, picture recognition,
finger tapping) and measurement of systemic cholinergic parameters were
measured during each of these phases. Patients were classified as
physostigmine responders and nonresponders based on a priori established
criteria. Using these, nine patients were found to respond to
physostigmine, while 11 were classified as nonresponders. During
baseline conditions, responders when compared to nonresponders were
found to have higher concentrations of red blood cell (RBC) choline (Ch)
and higher ratios of RBC Ch to plasma Ch. Neuropsychological tests were
found to fall into one of three categories. The first group of tests
were sensitive to drug effects and differentiated physostigmine
responders from nonresponders; the second group was found to predict
responsiveness; and the third group was neither predictive nor sensitive
to drug effects.

631\. Hunter, R., *et al.*, *Cerebral pharmacodynamics of physostigmine
in Alzheimer\'s disease investigated using single-photon computerised
tomography.* Br J Psychiatry, 1991. 158: p. 351-7. The effects of
physostigmine on patterns of rCBF in patients with pre-senile
Alzheimer\'s disease were studied using 99mTc-labelled HMPAO SPECT.
Regional CBF increased in the left cortex relative to right, with the
most significant effect in left frontal and higher frontal regions.
Measures of regional brain function, such as SPECT, are an important
complement to psychological test batteries in understanding the effects
in brain of putative antidementia drugs. SPECT brain imaging could
extend our understanding of the action of psychotropic drugs in other
major psychiatric illnesses.

632\. Iijima, S., *et al.*, *Phenserine: a physostigmine derivative that
is a long-acting inhibitor of cholinesterase and demonstrates a wide
dose range for attenuating a scopolamine-induced learning impairment of
rats in a 14-unit T-maze.* Psychopharmacology (Berl), 1993. 112(4): p.
415-20. Phenserine ((-)-N-phenylcarbamoyl eseroline), a carbamate analog
of physostigmine (Phy), is a long-acting inhibitor of cholinesterase. We
have assessed the potential clinical value of phenserine for
cholinomimetic therapy of cognitive impairments associated with aging
and Alzheimer\'s disease by evaluating its duration of in vivo activity
against rat plasma acetylcholinesterase (AChE) and its effect on
attenuating a scopolamine-induced impairment in learning performance of
young rats in a shock-motivated 14-unit T-maze. Phenserine achieved
maximum AChE inhibition of 73.5% at 5 min and maintained a high and
relatively constant inhibition for more than 8 h. For analysis of
effects on learning performance, 69, 3-month-old male Fischer-344 rats
were pretrained in a straight runway to avoid electric footshock. On the
following day, each animal received 15 trials in the 14-unit T-maze.
Sixty minutes prior to the maze training, each rat received the first IP
injection of either vehicle (Tween 80, ethanol and 0.9% NaCl) or
phenserine at 1.5, 3.0, 4.0, 5.0, 7.5, or 10.0 mg/kg. Then 30 min prior
to the training, each animal received a second IP injection of either
0.9% NaCl or scopolamine hydrochloride (0.75 mg/kg; SCOP). Compared to
the vehicle-SCOP group, all but the 7.5 mg/kg dose of phenserine
significantly ameliorated error performance, runtime, shock frequency
and shock duration in SCOP-treated rats at the final block of three
trials. Appearing to have a long effect and a wide therapeutic window,
phenserine deserves further study as a cognitive enhancer.

633\. Jenike, M.A., *et al.*, *Oral physostigmine treatment for patients
with presenile and senile dementia of the Alzheimer\'s type: a
double-blind placebo-controlled trial.* J Clin Psychiatry, 1990. 51(1):
p. 3-7. Twelve patients aged 53 to 89 years with presenile or senile
dementia of the Alzheimer\'s type participated in a treatment trial of
oral physostigmine. Patients first received the drug during an open
dose-finding phase. In a double-blind crossover design phase, the
patients\' memory performance during treatment with an optimal
memory-enhancing dose was compared with memory performance during
placebo treatment. Response to medication was assessed by the Delayed
Recognition Span Test, the Selective Reminding Test, and the
Alzheimer\'s Disease Assessment Scale. Intergroup differences in
response to physostigmine were nonsignificant. Age at onset of the
disease did not differentiate partial responders from nonresponders.

634\. Jenike, M.A., M.S. Albert, and L. Baer, *Oral physostigmine as
treatment for dementia of the Alzheimer type: a long-term outpatient
trial.* Alzheimer Dis Assoc Disord, 1990. 4(4): p. 226-31. Six patients
with dementia of the Alzheimer type (DAT), treated with oral
physostigmine and followed from 9 to 27 months (mean +/- SD, 17.8 +/-
7.3 months), were matched for sex, age, initial degree of dementia, and
length of follow-up with six control patients who did not receive oral
physostigmine. The small sample size precluded drawing definite
conclusions about overall efficacy; however, three in the physostigmine
group did not deteriorate during the course of follow-up while all of
the controls deteriorated although the difference was nonsignificant.
The data generated in these patients provides evidence of the safety of
long-term trials of oral physostigmine. The possible role of
cholinesterase inhibition in retarding the progression of DAT is
discussed.

635\. Jenike, M.A., *et al.*, *Oral physostigmine as treatment for
primary degenerative dementia: a double-blind placebo-controlled
inpatient trial.* J Geriatr Psychiatry Neurol, 1990. 3(1): p. 13-6.
Twenty-three patients with primary degenerative dementia (Alzheimer\'s
disease) were administered an optimal dose of oral physostigmine and
placebo, each for a 1-week period, under double-blind conditions on a
research unit of a general hospital. Each patient served as his or her
own control. The optimal dose of physostigmine for each patient was
determined previously by a dose-finding phase. There were no significant
group differences on a number of neuropsychological tests. Along with
other studies in the literature, this study casts serious doubt on the
efficacy of short-term administration of oral physostigmine when used
alone in an attempt to ameliorate cognitive dysfunction in Alzheimer\'s
disease patients. The possibilities that physostigmine may slow the
course of the disease or may acutely improve symptoms when combined with
other agents are discussed.

636\. Jotkowitz, S., *Lack of clinical efficacy of chronic oral
physostigmine in Alzheimer\'s disease.* Ann Neurol, 1983. 14(6): p.
690-1. Ten patients with mild to severe Alzheimer\'s disease were
treated for up to 10 months with 10 to 15 mg oral physostigmine daily or
with placebo, according to a single blind, multiple crossover protocol.
No clinically meaningful improvement occurred with physostigmine
treatment.

637\. Lahiri, D.K. and M.R. Farlow, *Differential effect of tacrine and
physostigmine on the secretion of the beta-amyloid precursor protein in
cell lines.* J Mol Neurosci, 1996. 7(1): p. 41-9. The senile plaque in
Alzheimer\'s disease (AD) consists mainly of the amyloid beta-peptide (A
beta) derived from a family of large integral membrane glycoproteins,
beta-amyloid precursor proteins (beta APP). Soluble derivatives of beta
APP generated by the proteolytic processing of full-length beta APP are
normally secreted into the conditioned medium of cultured cells. Here we
have investigated the possibility that the processing of beta APP can be
regulated by the cholinesterase inhibitors physostigmine and tacrine.
Both drugs mildly improve cognitive functions in some patients with AD.
We analyzed the level of beta APP in glial, neuroblastoma, and
pheochromocytoma cells by immunoblotting cell lysates and conditioned
media using a monoclonal antibody, MAb22C11. The levels of soluble beta
APP derivatives normally present in conditioned media were severely
inhibited by treating cells with tacrine but not with physostigmine.
Whereas the treatment of cells with tacrine resulted in a small decrease
in the intracellular levels of beta APP, treating cells with
physostigmine resulted in a slight increase in the intracellular levels
of beta APP compared to untreated cells. The effect of tacrine on the
secretion of beta APP was not affected by cotreating cells with
muscarinic agents, staurosporine, or the calcium ionophore. Our results
suggest that a decrease in the secretion of beta APP by tacrine did not
depend on its anticholinesterase activity and that tacrine operates via
a noncholinergic mechanism.

639\. Levin, H.S. and B.H. Peters, *Long-term administration of oral
physostigmine and lecithin improve memory in Alzheimer\'s disease.* Ann
Neurol, 1984. 15(2): p. 210.

640\. Levy, A., *et al.*, *Transdermal physostigmine in the treatment of
Alzheimer\'s disease.* Alzheimer Dis Assoc Disord, 1994. 8(1): p. 15-21.
Physostigmine has been reported to improve the memory function of some
patients with Alzheimer\'s Disease (AD). However, the drug has a short
half-life and a narrow therapeutic window. To overcome these
impediments, we developed a continuous transdermal delivery system and
tested it for 2 weeks in 12 AD inpatients, using a single-blind design.
No major adverse effects were recorded in any of the patients.
Physostigmine plasma concentrations were relatively stable (0.56 +/-
0.10 ng/ml) and correlated well with blood acetylcholinesterase
inhibition. Six of the 12 patients reported improved vigilance and
concentration, and also had higher scores in all four neuropsychological
tests employed (Mini Mental State examination, Short Mental Test
\[SMT\], Wechsler\'s Memory Scale \[WMS\], and Buschke\'s Selective
Reminding Test). The performance of two additional patients improved in
only two tests (SMT and WMS). Transdermal delivery of physostigmine
appears to be safe and may be useful for the treatment of a subset of AD
patients.

641\. Linville, D.G., E. Giacobini, and S.P. Arneric,
*Heptyl-physostigmine enhances basal forebrain control of cortical
cerebral blood flow.* J Neurosci Res, 1992. 31(3): p. 573-7. This study
sought to determine the effect of heptylphysostigmine (H-PHY), a
reversible cholinesterase (ChE) inhibitor with greater lipophilicity and
longer duration of action than physostigmine, on resting and basal
forebrain (BF)-elicited increases in cortical cerebral blood flow (CBF).
Laser-doppler flowmetry (LDF) was used to monitor changes in frontal
cortical microvascular perfusion in urethane anesthetized rats.
Responses were measured before, early after, and 1 hr following H-PHY, 3
mg/kg, i.m. Electrical stimulation (100 microA) of the BF elicited up to
220% increases in CBF at 50 Hz, an effect that was graded with
frequency. At 15 min following H-PHY (3 mg/kg) resting cortical CBF was
unchanged, whereas BF-elicited increases were potentiated 47% at 50 Hz.
At 1 hour, resting cortical CBF remained unchanged, and the BF-elicited
responses were remarkably potentiated by 354% at 10 Hz and 67% at 50 Hz.
Acetylcholinesterase (AChE) activity measured in the tissue directly
beneath the LDF probe was decreased by 84% at a time when these CBF
responses were enhanced. These data suggest that H-PHY substantially
enhances the regulation of cortical CBF by the BF, an effect that may be
linked to inhibition of cortical AChE activity. This enhancement of
cortical CBF may contribute to the efficacy of H-PHY as a treatment for
Alzheimer\'s disease.

642\. Mandel, R.J., *et al.*, *Continuous physostigmine infusion in rats
with excitotoxic lesions of the nucleus basalis magnocellularis: effects
on performance in the water maze task and cortical cholinergic markers.*
J Pharmacol Exp Ther, 1989. 251(2): p. 612-9. Acute peripheral
administration of physostigmine inhibits cortical acetylcholinesterase
(AChE) for about 1 hr in the rat and improves performance on learning
and memory paradigms after excitotoxic lesions of the nucleus basalis
magnocellularis (NBM) in rats. This study examined the effects of
continuous systemic infusion of physostigmine using osmotic minipumps.
One week of continuous physostigmine infusion in normal animals
inhibited cortical AChE activity in a dose-dependent manner. Doses
causing near maximal (0.06 mg/kg/hr) and ED50 (0.0075 mg/kg/hr)
inhibition of cortical AChE activity were used to determine the effects
of continuous physostigmine administration on spatial learning in the
water maze in rats with bilateral ibotenic acid lesions of the NBM.
Physostigmine had no effect on the acquisition of the maze task but
prevented the retention deficit measured in untreated NBM-lesioned rats.
Physostigmine treatment also improved the search strategy during the
spatial probe trial compared to the untreated NBM-lesioned rats. The two
doses of physostigmine examined did not produce differential responses
on behavioral measures. Although NBM lesions significantly depleted
cortical AChE activity, physostigmine treatment reduced the activity
further in a dose-dependent manner. Whereas neither the lesion nor the
low dose of physostigmine altered cortical receptor binding, the higher
dose of physostigmine significantly down-regulated cortical muscarinic
receptor binding by 28%. These data demonstrate that enhancement of
acetylcholine neurotransmission can improve memory loss and spatial
strategy associated with excitotoxic NBM lesions.

643\. Marin, D.B., *et al.*, *L-deprenyl and physostigmine for the
treatment of Alzheimer\'s disease.* Psychiatry Res, 1995. 58(3): p.
181-9. The present study evaluated the safety of and obtained
preliminary data on the cognitive effects of L-deprenyl and
physostigmine in patients with Alzheimer\'s Disease. Seventeen
outpatients with Alzheimer\'s Disease participated in a double-blind
crossover study in which they received 4 weeks of L-deprenyl at a dose
of 10 mg p.o., q.d., and 4 weeks of placebo in random order. During both
the L-deprenyl and placebo periods, patients received cognitive
assessments during physostigmine (0.5 mg) and placebo infusions
separated by 2 days. The cognitive effects of these agents alone and in
combination were measured with digit span, verbal fluency, list
learning, praxis, delayed recall, and delayed recognition tasks. Fifteen
patients completed the study. The two drugs, used alone or in
combination, were safe and well tolerated. Analyses of variance
demonstrated that neither physostigmine nor L-deprenyl, whether given
alone or in combination, significantly improved cognition, when compared
with the double placebo condition.

644\. Marta, M., *et al.*, *New analogs of physostigmine: alternative
drugs for Alzheimer\'s disease?* Life Sci, 1988. 43(23): p. 1921-8. The
synthesis of a series of physostigmine analogs, in which the
methylcarbamyl group has been substituted with monoalkylcarbamyl,
dimethyl- and diethylcarbamyl groups, is reported. These compounds were
prepared with the aim of investigating their possible therapeutic
effects in the treatment of Alzheimer\'s type dementia. The new analogs
of physostigmine are inhibitors of acetylcholinesterase from
Electroforus electricus, with a value of the reactivation constant, k3
smaller than the one of physostigmine. The percentage of
anticholinesterase activity in vitro and in vivo, the acute toxicity and
some behavioural effects were also evaluated for selected derivatives.
The reactivation constant, in vitro, supports the view that the
derivatives described would be more suitable for therapeutic use than
physostigmine.

645\. Mattio, T., *et al.*, *The effects of physostigmine on
acetylcholinesterase activity of CSF plasma and brain. A comparison of
intravenous and intraventricular administration in beagle dogs.*
Neuropharmacology, 1986. 25(10): p. 1167-77. The effects of various
doses of physostigmine (Phy) on the activity of acetylcholinesterase
(AChE) in plasma, cerebrospinal fluid (CSF) and brain were studied in
beagle dogs. Two routes of administration were compared: intravenous
(i.v.) and intracerebroventricular (i.c.v.). With
intracerebroventricular administration, over 90% inhibition of the
activity of AChE in CSF was reached within 5 min of injection at all
doses (10-120 micrograms). Even at the smallest dose (10 micrograms),
50% inhibition of activity of the enzyme in CSF was still present at 90
min. The activity of AChE in plasma was only minimally inhibited by
intraventricular administration of physostigmine. A different response
was obtained following intravenous administration of physostigmine
(250-1000 micrograms). The activity of AChE in plasma was inhibited but
the activity of AChE in CSF was increased (36-80% at 180 min). This
increase was dose-dependent and was blocked by pretreatment with
atropine (1.5 mg i.v.) which suggests the involvement of a muscarinic
receptor mechanism. The time course of the accumulation and regional
distribution of \[3H\]physostigmine in brain also varied with the route
of administration. At 5 min, with intravenous administration,
physostigmine (1000 micrograms) reached greater concentrations and
caused greater inhibition of AChE in the cortex. With intraventricular
administration, physostigmine (80 micrograms) reached greater
concentrations in two regions adjacent to the ventricular surface: the
striatum and hippocampus. These regions also showed greater inhibition
of the activity of AChE. Moderate to severe symptoms of cholinergic
hyperactivity were seen only with the largest intraventricular dose (120
micrograms). This study suggests that intraventricular administration of
physostigmine, a reversible inhibitor of cholinesterase (ChE), may offer
distinct advantages over intravenous administration. Inhibition of
acetylcholinesterase in CSF was more pronounced and persisted longer
when physostigmine was administered directly into the CSF than when
given intravenously. The implications of this study for a cholinergic
therapy of Alzheimer\'s disease are discussed.

646\. Mayeux, R., M. Albert, and M. Jenike, *Physostigmine-induced
myoclonus in Alzheimer\'s disease.* Neurology, 1987. 37(2): p. 345-6.
Physostigmine caused myoclonus in two patients with Alzheimer\'s disease
during a clinical trial. Neither patient had myoclonus before or after
physostigmine treatment. We hypothesize that physostigmine reduced the
sensitivity of the remaining muscarinic receptors in these two patients,
altering the interaction between cholinergic and either serotoninergic
or dopaminergic neurotransmitter systems.

647\. Mellow, A.M., *et al.*, *A peptide enhancement strategy in
Alzheimer\'s disease: pilot study with TRH-physostigmine infusions.*
Biol Psychiatry, 1993. 34(4): p. 271-3. .

648\. Mohs, R.C., *et al.*, *Oral physostigmine treatment of patients
with Alzheimer\'s disease.* Am J Psychiatry, 1985. 142(1): p. 28-33.
Twelve patients with Alzheimer\'s disease received 0.0, 0.5, 1.0, 1.5,
and 2.0 mg of oral physostigmine every 2 hours for 3-5 days; symptoms
after each dose were assessed with the Alzheimer\'s Disease Assessment
Scale. Placebo and the dose associated with the least severe symptoms
were then readministered for 3-5 days each. Of the 10 patients who
completed the study, three showed clinically significant improvement on
the highest physostigmine dose in both phases, four more were marginally
improved in both phases, and three had inconsistent responses to
physostigmine. Cortisol measures obtained during a sleep study suggest
that patients whose symptoms improved on physostigmine were those in
whom oral physostigmine enhanced central cholinergic activity.

649\. Molchan, S.E., *et al.*, *Reciprocal changes in psychosis and mood
after physostigmine in a patient with Alzheimer\'s disease.* Arch Gen
Psychiatry, 1991. 48(12): p. 1113-4. .

650\. Moller, H.J., *et al.*, *Double-blind, randomized,
placebo-controlled clinical trial on the efficacy and tolerability of a
physostigmine patch in patients with senile dementia of the Alzheimer
type.* Pharmacopsychiatry, 1999. 32(3): p. 99-106. Owing to the
pharmacokinetic properties of physostigmine when administered by
conventional routes, long-term cholinergic treatment of Alzheimer\'s
disease is difficult to manage. In order to overcome the problems
associated with the oral and intravenous application of physostigmine,
and to improve patients\' compliance, a transdermal therapeutic system
was developed. The efficacy and tolerability of this system were
evaluated in a double-blind, randomized, multicenter study comparing
patches containing 30 mg and 60 mg physostigmine with a placebo patch.
The clinical trial followed the basic principles of the various
guidelines on the evaluation of anti-dementia drugs, and included
patients with mild to moderate probable Alzheimer\'s disease. A total of
204 patients with probable Alzheimer\'s disease were included in the
study. Of these, 136 patients were eligible for the
according-to-protocol analysis of efficacy, 167 subjects for the
intention-to-treat analysis of efficacy, and 181 patients were included
in the safety analysis. In contrast to the hypothesis to be tested, the
efficacy of physostigmine was not superior to that of placebo after a
treatment period of 24 weeks. On the contrary, there was even a slight,
but not statistically significant, trend toward a better outcome in the
placebo group. Median physostigmine plasma concentrations of
approximately 100 pg/ml were measured, showing a high degree of
interindividual variability and no linear dose relationship between the
30 mg and 60 mg dosages. Plasma cholinesterase activity was not
significantly affected by physostigmine. The physostigmine patch
application in doses of 30 mg and 60 mg apparently did not lead to
physostigmine plasma concentrations that were sufficient to compensate
for cholinergic deficiencies in affected brain areas and produce
clinical benefits. Both the drug and the transdermal system were
generally well tolerated under the study conditions. Modifications of
the patch system may perhaps make it possible to achieve higher
physostigmine plasma concentrations, which seem to be required to induce
the expected beneficial effects during long-term treatment of
Alzheimer\'s disease.

651\. Muir, J.L., *et al.*, *Attentional functions of the forebrain
cholinergic systems: effects of intraventricular hemicholinium,
physostigmine, basal forebrain lesions and intracortical grafts on a
multiple-choice serial reaction time task.* Exp Brain Res, 1992. 89(3):
p. 611-22. Degeneration of the cholinergic magnocellular neurons in the
basal forebrain and their cortical projections is a major feature of the
neuropathology of Alzheimer\'s disease. In the present study, two
experiments examined the disruptive effects on visual attentional
performance of two different manipulations that reduce central
cholinergic function. In Expt. I, pharmacological manipulation of the
cholinergic system was investigated using icv administration of
hemicholinium (HC-3), a high affinity choline uptake blocker,
administered either alone or in conjunction with the anticholinesterase,
physostigmine. The results revealed impairments in the ability of the
rats to localize brief visual targets in a serial reaction time task, as
shown in particular by a reduction in choice accuracy and lengthening of
the latency to respond correctly to the visual stimulus. Cholinergic
specificity was supported by the reversal of these behavioural
impairments by pre-treatment with the anticholinesterase, physostigmine.
In Expt. II, quisqualate-induced lesions of the basal forebrain produced
behavioural deficits at 3 weeks post-lesion surgery similar to those
observed following icv infusion of HC-3. In an attempt to restore the
extrinsic cortical cholinergic innervation by reinnervation of the
deafferented cortex, embryonic basal forebrain cholinergic cells were
transplanted into the cortex of lesioned animals. After three months
recovery, impairments in performance on the baseline schedule of the
task were no longer apparent in lesioned animals. However, behavioural
deficits, observed predominantly as a lengthening of correct response
latency, could be reinstated in the lesioned animals by interpolation of
distracting bursts of white noise during each trial, and this deficit
was ameliorated by the cholinergic grafts. Furthermore, a non-specific
effect of both cholinergic and non-cholinergic grafts in controlling the
increase in perseverative time-out responses which occurred as a result
of the basal forebrain lesion was consistently observed. These results
suggest that cholinergic dysfunction can produce deficits in visual
attention which can be ameliorated by cholinergic treatments such as
physostigmine or cholinergic-rich cortical grafts. These data provide
support for a role for the basal forebrain-neocortical cholinergic
projection in attentional function.

652\. Muramoto, O., M. Sugishita, and K. Ando, *Cholinergic system and
constructional praxis: a further study of physostigmine in Alzheimer\'s
disease.* J Neurol Neurosurg Psychiatry, 1984. 47(5): p. 485-91.
Subcutaneous or intravenous administration of physostigmine improved the
copying of geometric figures in three out of six patients with presumed
Alzheimer\'s disease who showed a remarkable constructional disturbance.
This improvement reached its maximum 30 to 60 minutes after the
physostigmine administration. These results not only provide further
evidence supporting the hypothesis that central cholinergic potentiation
ameliorates some of the impairments of Alzheimer\'s disease, but
implicate a possible important role of the cholinergic system in the
integration of constructional praxis.

653\. Perola, E., *et al.*, *Long chain analogs of physostigmine as
potential drugs for Alzheimer\'s disease: new insights into the
mechanism of action in the inhibition of acetylcholinesterase.* Biochim
Biophys Acta, 1997. 1343(1): p. 41-50. Heptylphysostigmine is in
advanced clinical trial as a drug for Alzheimer\'s disease.
8-Morpholinooctylphysostigmine and
8-(cis-2,6-dimethylmorpholino)octylphysostigmine are currently
undergoing pre-clinical evaluation. The mechanism of action of these
compounds in the inhibition of acetylcholinesterase has been
investigated. All the examined compounds display non competitive-like
kinetics of inhibition. There are no reversible components in the
observed inhibition: the whole inhibitory effect is due to the
time-dependent pseudo-irreversible carbamylation of the active site. Yet
the observed time course of the inhibition does not match a simple
second order kinetics. An influence of the quaternary structure of the
enzyme on the more complex kinetics of carbamylation is hypothesized.
Reactivation experiments on the inhibited enzyme show long lasting
inhibitory effects for these compounds. The higher duration of the
anticholinesterase effect of the morpholino derivatives compared to
heptylphysostigmine should provide the basis for their higher
therapeutic potential.

654\. Peruzzi, P., D. von Euw, and P. Lacombe, *Differentiated
cerebrovascular effects of physostigmine and tacrine in cortical areas
deafferented from the nucleus basalis magnocellularis suggest
involvement of basalocortical projections to microvessels.* Ann N Y Acad
Sci, 2000. 903: p. 394-406. Cholinesterase inhibitors used to treat
Alzheimer\'s disease according to the principle of cholinergic
replacement therapy have proved to be less beneficial than expected. The
present study was designed to investigate the cerebrovascular response
to physostigmine and tacrine in the experimental model of lesioning of
the nucleus basalis magnocellularis (NBM), a model involving a
cholinergic deficit. Regional cerebral blood flow was measured by the
\[14C\]iodoantipyrine tissue sampling technique in conscious rats
infused with i.v. physostigmine (0.2 mg/kg/h), tacrine (8 mg/kg/h), or
saline, 3-5 weeks after unilateral lesion of the NBM with ibotenic acid.
Physostigmine and tacrine dose-dependently increased blood flow in most
cortical and subcortical regions compared to the control group. However,
physostigmine caused smaller blood flow increases in several areas,
mostly cortical, of the lesioned compared to the intact hemisphere. The
converse was observed with tacrine. A facilitated circulatory response
appeared in cortical areas deafferented from the NBM, especially in the
frontal cortex. These results provide evidence for distinct
NBM-dependent components of the cortical cerebrovascular effects of
physostigmine and tacrine. They suggest the involvement of different
cellular postsynaptic targets of the NBM. The physostigmine-type effects
could involve direct projects onto an inhibitory cortical interneuron
supersensitized by deafferentation. This arrangement may explain why
physostigmine and perhaps other cholinergic agonists are unable to
specifically compensate for a deficit in NBM functioning. The
tacrine-type effects presumably involve projections to the
microvasculature, including perivascular astrocytes. The neurovascular
junction would be sensitized by deafferentation from the NBM. Our data
suggest that the regulatory mechanisms of blood flow originating in the
NBM might constitute a target of neurodegenerative processes of
Alzheimer\'s disease.

655\. Prohovnik, I., *et al.*, *Physostigmine reversal of
scopolamine-induced hypofrontality.* J Cereb Blood Flow Metab, 1997.
17(2): p. 220-8. The muscarinic receptor antagonist scopolamine produces
a transient memory deficit in healthy humans. This deficit has been
offered as a model of the cholinergic deficit of Alzheimer\'s disease
(AD). However, we have previously shown that scopolamine produces a
deficit of cortical perfusion maximal in the frontal lobe, dissimilar to
the parietal cortex deficit characteristic of AD. The current experiment
was aimed at replicating and extending this observation by critically
testing the central cholinergic origin of both cognitive and perfusion
deficits. Nine healthy subjects participated in regional cerebral blood
flow (rCBF) measurements at baseline, after scopolamine (7.2
micrograms/kg i.v.), and after both physostigmine (22 micrograms/kg
i.v.) and neostigmine (7 or 11 micrograms/kg i.v.). rCBF was quantified
by the xenon 133 inhalation method. As expected, scopolamine reduced
cortical perfusion, mainly in the frontal cortex, and produced a memory
deficit. Physostigmine, but not neostigmine, reversed all three
variables partially or completely. These results support the hypothesis
that all three consequences of scopolamine, namely, reduction of mean
flow, frontal deficit, and memory impairment, are cholinergically
mediated. Furthermore, because neostigmine poorly crosses the
blood-brain barrier, these findings confirm that the effect is centrally
mediated and cannot be explained by peripheral effects. However, they
also confirm the frontal cortex locus of action for both scopolamine and
its reversal by physostigmine and therefore suggest a major
dissimilarity to the characteristic rCBF appearance of AD. This study
extends our previous preliminary findings with tacrine and strengthens
the suggestion that only nicotinic receptors are associated with the
characteristic parietal deficit of AD.

656\. Ritzmann, R.F., *et al.*, *The interaction of ethanol with the
cognitive enhancers tacrine, physostigmine, and AIT-082.* J Gerontol,
1994. 49(2): p. B51-3. Because tacrine, a cognitive enhancing agent, was
being considered for approval for use in Alzheimer\'s disease, its
possible interaction with ethanol, a commonly used substance to which
elderly individuals are generally more sensitive than younger
individuals, was explored. For purposes of comparison, two other drugs,
which have also been shown to improve memory in mice, at doses which had
activity in a working memory paradigm, were evaluated for an interaction
with ethanol. Ethanol-induced sedation in mice was increased by tacrine
and decreased by physostigmine, whereas AIT-082 did not alter sedation.
However, tacrine had no effect on body temperature or on ethanol-induced
hypothermia. Neither tacrine nor physostigmine had any effect on the
rate of ethanol elimination from the blood. As tacrine comes into
clinical use in the treatment of Alzheimer\'s disease, adverse
interactions with ethanol should be explored further.

657\. Rose, R.P. and M.A. Moulthrop, *Differential responsivity of
verbal and visual recognition memory to physostigmine and ACTH.* Biol
Psychiatry, 1986. 21(5-6): p. 538-42. .

658\. Rupniak, N.M., *et al.*, *Reversal of cognitive impairment by
heptyl physostigmine, a long-lasting cholinesterase inhibitor, in
primates.* J Neurol Sci, 1992. 107(2): p. 246-9. Cholinergic replacement
therapy for Alzheimer\'s disease using existing cholinesterase
inhibitors is compromised by short duration, meagre benefits restricted
to subgroups of patients, and peripheral toxicity. Heptyl physostigmine
is a lipophilic carbamate derivative of physostigmine. In rhesus
monkeys, heptyl physostigmine (0.2-0.9 mg/kg i.m.) fully reversed a
scopolamine-induced cognitive impairment. Following oral administration
in squirrel monkeys, heptyl physostigmine (8 mg/kg) induced long-lasting
hypothermia (greater than or equal to 4 h), a centrally-mediated
cholinergic effect. Erythrocyte acetylcholinesterase activity was
inhibited by 86% at the time of peak hypothermia (180 min). Clinical
trials with heptyl physostigmine will enable a more rigorous evaluation
of cholinomimetic therapy for dementia.

659\. Sano, M., *et al.*, *Safety and efficacy of oral physostigmine in
the treatment of Alzheimer disease.* Clin Neuropharmacol, 1993. 16(1):
p. 61-9. Results of therapeutic trials with physostigmine in the
treatment of Alzheimer disease (AD) have been inconsistent and
controversy persists concerning safety and efficacy. In a double-blind,
placebo-controlled, crossover study, patients received 6 weeks of oral
physostigmine (OP) and placebo in random order. Twenty-nine patients
with AD received as much as 16 mg/day of OP and were assessed with
neuropsychological and functional measures. No significant cardiac side
effects were noted, though other systemic adverse effects were noted,
requiring dose reduction in four patients. There was a slight but
significant improvement (12%) in performance on the selective reminding
test with physostigmine and the memory performance was correlated with
dosage. This improvement compares favorably with the 15% decrease in
scores seen in an untreated comparison cohort followed for an equivalent
time period. There was a trend toward an improvement in communication
and a reduction in memory complaint. These results suggest that oral
physostigmine is safe and may improve memory in AD.

660\. Schwartz, A.S. and E.V. Kohlstaedt, *Physostigmine effects in
Alzheimer\'s disease: relationship to dementia severity.* Life Sci,
1986. 38(11): p. 1021-8. Eleven demented patients were administered
.004, .009, and .013 mg/kg physostigmine intramuscularly, and placebo,
double-blind, in Phase 1. The most effective dose, in terms of showing
the best memory score as compared to saline, was repeated during Phase
2. Five patients improved their verbal memory scores in both Phases 1
and 2 after the most effective dose of physostigmine; these five
\"responders\" were found to be significantly more demented than the six
\"nonresponders.\" Drug-induced increases in memory scores were
significantly correlated with illness severity. Intrusions, which were
not a factor in selection of the most effective dose, were reduced in
the group as a whole, with the responders showing the most improvement
and the nonresponders the least. The association between physostigmine
effect and degree of dementia suggests to us that the severe cases may
have more permeable blood-brain barriers, and that drug availability to
the brain is an important factor in evaluating treatment of SDAT with
cholinergic substances.

661\. Sevush, S., A. Guterman, and A.V. Villalon, *Improved verbal
learning after outpatient oral physostigmine therapy in patients with
dementia of the Alzheimer type.* J Clin Psychiatry, 1991. 52(7): p.
300-3. BACKGROUND: Previous investigators have reported improvements in
verbal learning in outpatients suffering from dementia of the Alzheimer
type (DAT) when they were treated daily with oral physostigmine for
periods of days to months. Questions remain, however, regarding both the
specificity of the induced cognitive changes and the time course of the
biological activity of the drug when physostigmine was used to treat DAT
patients. We examined both of these parameters in an outpatient,
double-blind, placebo-controlled study that examined the effect of
physostigmine on memory and other cognitive functions. METHOD: Eight DAT
patients were treated for 3 weeks with oral physostigmine administered
four times daily in a double-blind, crossover, placebo-controlled study.
An auditory verbal learning test (AVLT) was administered to assess
verbal learning. Digit span, word fluency, and frequency of intrusions
served as controls for nonspecific changes in attention and verbal
responsiveness. RESULTS: AVLT scores improved after drug administration
compared with scores for baseline and placebo performances (p = .04).
Other measures were unchanged. Improvement was unrelated to the time
interval between memory testing and last ingested dose. CONCLUSIONS:
These results indicate a longer period of biological activity for
physostigmine than previously considered and extend previous reports of
improved verbal learning after oral physostigmine treatment to a more
convenient dosing schedule. These results suggest further that the
improvements induced by physostigmine result specifically from
enhancement of long-term memory processes.

662\. Smith, C.M. and M. Swash, *Physostigmine in Alzheimer\'s disease.*
Lancet, 1979. 1(8106): p. 42. .

663\. Somani, S.M., L.K. Unni, and D.L. McFadden, *Drug interaction for
plasma protein binding: physostigmine and other drugs.* Int J Clin
Pharmacol Ther Toxicol, 1987. 25(8): p. 412-6. Physostigmine (Phy) has
gained prominence recently because of its use in the treatment of
Alzheimer\'s disease and also as a prophylactic agent in the treatment
of organophosphate intoxication. Since Alzheimer\'s disease is usually
confined to the older population, the patients generally receive more
than one medication. The present study examined whether Phy is displaced
from the plasma protein binding site in vitro by a number of commonly
prescribed drugs used in this patient population, using therapeutic
range of blood levels. The binding of Phy to plasma proteins decreased
in the presence of quinidine (3-15 micrograms/ml), from 45.5-5.3%,
furosemide (1-100 micrograms/ml) from 45.5-28.4%, acetaminophen (10-160
micrograms/ml) 48.8-37.9%, theophylline (6.67-80 micrograms/ml)
52.2-43.7%, verapamil (0.1-0.5 micrograms/ml) 44.8-34.9%. However,
imipramine (0.05-0.2 micrograms/ml), chlorpromazine (0.1-2
micrograms/ml) and propranolol (0.02-0.04 micrograms/ml) did not affect
the binding of Phy irrespective of whether the plasma samples were
preincubated with Phy or not. The binding of Phy to alpha 1-acid
glycoprotein (50 mg/dl), gamma-globulin (1.3 mg/dl) and low density
lipoprotein (0.83 mg/ml) was very small (less than 15%), contributing to
about one-third of the total plasma protein binding. It appears that the
binding of Phy to human plasma proteins was altered to a significant
degree in the presence of quinidine, furosemide, acetaminophen,
theophylline and verapamil. Free fraction of Phy in plasma has increased
which could lead to greater toxicity of Phy.

664\. Somani, S.M. and S.N. Dube, *Physostigmine\--an overview as
pretreatment drug for organophosphate intoxication.* Int J Clin
Pharmacol Ther Toxicol, 1989. 27(8): p. 367-87. Physostigmine (Phy) is
one of the oldest drug isolated from Calabar beans and successfully used
for the treatment of glaucoma in 1864. Since then, it has been widely
employed for various therapeutic purposes. Recently, it has gained
prominence because of its clinical trials in the treatment of
Alzheimer\'s disease. Phy is also considered to be a potent prophylactic
antidote for organophosphate poisoning. It is a reversible
cholinesterase (ChE) inhibitor and has a short duration of action. It
crosses the blood-brain barrier readily. Hence, it is a centrally acting
carbamate. For the last 50 years, numerous authors have shown that
pretreatment with Phy would rapidly improve the incapacitating effects
of organophosphate intoxication in various animal species. Phy
carbamylates to a portion of ChE enzyme and thus protects the enzyme
from binding with organophosphate, which are irreversible ChE
inhibitors. Organophosphates are metabolized very quickly in the body or
bind to non-specific binding sites. The carbamylated ChE enzyme
decarbamylates to free the enzyme for normal functioning. The rates of
decarbamylation of butyrylcholinesterase (BuChE) in plasma and ChE in
brain and muscle are different and are related to the half-life of Phy
in these tissues. In addition to ChE inhibition, Phy has got a direct
action on acetylcholine (ACh) receptor ionophore complex by interacting
with the ACh-gated cation channels. Physostigmine has a half-life of 16,
23 and 30 min in rat, dog and man, respectively. The bioavailability of
Phy is very low (about 2%) and it is extensively metabolized in the
liver. Less than 4% of Phy is excreted unchanged in the urine and a
portion is also eliminated in the bile. Physostigmine has a narrow
margin of safety, and a slight increase in dose causes cholinergic
symptoms, which can be counteracted by cholinolytic therapy. This review
article deals with various aspects of physostigmine such as historical,
therapeutic uses, mechanisms of action, methods for the determination,
disposition and pharmacokinetics, toxicity and finally as an antidote
against organophosphate intoxication.

665\. Stern, Y., M. Sano, and R. Mayeux, *Effects of oral physostigmine
in Alzheimer\'s disease.* Ann Neurol, 1987. 22(3): p. 306-10. Previous
studies of oral physostigmine in the treatment of Alzheimer\'s disease
have: (1) assumed physostigmine is effective only in mildly affected
patients; (2) relied on an initial \"dose-finding\" phase to determine
the most effective dose and excluded nonresponders; and (3) primarily
assessed memory. We examined the response of 22 patients to six
different daily dosages of oral physostigmine, using selective reminding
tests that were administered twice daily. Nine patients had a \"best\"
dose/day (mode = 13 mg/day), which was used in a subsequent double-blind
crossover study. The other 13 were given the highest tolerated dose. The
selective reminding test and a full neuropsychological battery were
given during the drug and placebo periods. As a group, the 22 patients
improved significantly on the Wechsler Adult Intelligence Scale-Revised
Digit Symbol subtest and a shape cancellation task (p less than 0.05).
Nine patients showed improved performance on the selective reminding
test during physostigmine treatment, and 9 showed no response; 4
patients performed better during placebo treatment. Dose finding did not
help in predicting response in the crossover study; only 2 of the 9 who
showed improvement had a best dose. Dementia severity did not predict
crossover response. This suggests that: (1) physostigmine as
administered had no pronounced effect on memory in Alzheimer\'s disease;
(2) oral physostigmine produces no greater benefits on memory in mildly
than in moderately demented patients; (3) response in a dose-finding
phase does not predict response in double-blind crossover; and (4) Digit
Symbol and cancellation tasks may be more sensitive than memory tests to
the effects of oral physostigmine.

666\. Stern, Y., M. Sano, and R. Mayeux, *Long-term administration of
oral physostigmine in Alzheimer\'s disease.* Neurology, 1988. 38(12): p.
1837-41. Minimal short-term benefits with oral physostigmine have been
reported in Alzheimer\'s disease. We examined long-term oral
physostigmine therapy in 14 patients with probable Alzheimer\'s disease
in an extended double-blind crossover trial in which they received
physostigmine for five intervals of 4 to 6 weeks in length and placebo
for one interval determined at random. At each interval a Selective
Reminding Test was administered and three indexes were examined: total
recall, long-term recall, and intrusions. As a group, patients\' memory
test scores were significantly better during the drug period. Two
patients who previously had performed worse on drug than on placebo in a
short-term trial continued to do so. Nine of the remaining 12 patients
performed better on two or more measures on physostigmine compared with
placebo. In some cases scores improved up to 50% over placebo values.
This improvement was not predicted by response to medication in the
earlier short-term trial. Seven patients completed an additional
six-interval crossover trial. All but one continued to have improved
performance with oral physostigmine and, in grouped data, memory
measures remained significantly improved. These results suggest that
long-term administration of physostigmine in Alzheimer\'s disease may be
more effective than short-term. This benefit can be sustained for up to
a year in some patients.

667\. Sunderland, T., *et al.*, *A strategy of \"combination
chemotherapy\" in Alzheimer\'s disease: rationale and preliminary
results with physostigmine plus deprenyl.* Int Psychogeriatr, 1992. 4
Suppl 2: p. 291-309. Although the central cholinergic deficits are still
considered to be of primary importance in Alzheimer\'s disease, there is
great need for an expansion of the pharmacological approach in this
illness beyond the simple cholinergic replacement hypothesis. This
report focuses on the concept of \"combination chemotherapy\" in
Alzheimer\'s disease as the next generation of therapeutic strategies.
Based on earlier positive findings in Alzheimer patients with the
monoamine oxidase B inhibitor, 1-deprenyl, the authors speculate that a
combination of physostigmine, the short-acting cholinesterase inhibitor,
and 1-deprenyl might be more beneficial than either agent alone. The
authors outline a sample paradigm for such combination studies, report
preliminary data on the first 16 Alzheimer subjects to have received an
initial combination of physostigmine and deprenyl, and point to other
possible \"combination chemotherapy\" strategies for future study.

668\. Thal, L.J., *et al.*, *Oral physostigmine and lecithin improve
memory in Alzheimer disease.* Ann Neurol, 1983. 13(5): p. 491-6. Eight
patients with early Alzheimer disease were treated with gradually
increasing multiple daily doses of oral physostigmine and supplemental
lecithin. Six individuals showed improvement in total recall and
retrieval from long-term storage (LTR), with a decrease in intrusions (a
measure of inaccurate recall). The optimal individual dose was either
2.0 or 2.5 mg of physostigmine for each responding patient. Results of
this open trial were subsequently replicated during a double-blind
crossover trial comparing physostigmine treatment to placebo. All six
patients again demonstrated improvement in total recall and LTR, with a
decrease in intrusions. The decrease in intrusions was strongly
correlated with increasing inhibition of cholinesterase activity in
cerebrospinal fluid, suggesting that the degree of improvement in the
patient\'s memory was related to the amount of physostigmine that
reached the brain. Other neurotransmitters and metabolites in
cerebrospinal fluid were unaffected by the physostigmine therapy,
suggesting a specific effect of physostigmine on the cholinergic system.
The results suggest that small oral doses of physostigmine combined with
lecithin ingestion have therapeutic benefit for some patients with
Alzheimer disease.

669\. Thal, L.J., *et al.*, *Oral physostigmine and lecithin improve
memory in Alzheimer\'s disease.* Psychopharmacol Bull, 1983. 19(3): p.
454-6. .

670\. Thal, L.J., *et al.*, *Acute and chronic effects of oral
physostigmine and lecithin in Alzheimer\'s disease.* Prog
Neuropsychopharmacol Biol Psychiatry, 1986. 10(3-5): p. 627-36.
Alzheimer patients were treated with lecithin and gradually increasing
doses of oral physostigmine during a drug trial to determine if these
compounds would improve memory. Memory was measured using a selective
reminding task. Of 16 patients, 10 showed improvement in total recall,
retrieval from long-term storage and a decrease in intrusions. The
optimal dose was 2.0 mg or 2.5 mg of physostigmine per dose for most
patients. During a replication study, all 10 patients again responded.
During long-term (4 to 20 months) treatment of five patients, most
demonstrated continued drug response initially but then lost
responsiveness to physostigmine and their dementia progressed.
Physostigmine treatment appeared to improve memory with or without
concomitant lecithin therapy. However, progressive dementia ensued
despite physostigmine therapy. The degree of memory improvement
correlated with increasing cerebrospinal fluid cholinesterase inhibition
suggesting that memory improvement is associated with entry of
physostigmine into the brain.

671\. Thal, L.J., *et al.*, *Plasma physostigmine concentrations after
controlled-release oral administration.* Arch Neurol, 1989. 46(1): p.
13. .

672\. Thal, L.J., *et al.*, *Chronic oral physostigmine without lecithin
improves memory in Alzheimer\'s disease.* J Am Geriatr Soc, 1989. 37(1):
p. 42-8. Sixteen patients with early Alzheimer\'s disease (AD) completed
a 3-month outpatient double-blind parallel trial of oral physostigmine
versus placebo. Ten subjects received drug; six received placebo. After
a dose-titration phase, each patient was placed on his or her best dose
of drug or placebo. Subjects were evaluated with both memory and
nonmemory tasks. Seven of the ten drug-treated patients, but none of the
six placebo-treated patients, demonstrated improvement on a selective
reminding task, a test of verbal memory. Family members reported
improvement in six of ten drug-treated patients and none of six
placebo-treated individuals. There was a trend toward greater
improvement with increasing drug dose. There was no improvement on the
nonmemory tests administered. The data indicate that oral physostigmine
improves memory but not other areas of cognition.

673\. Thal, L.J., *et al.*, *A multicenter double-blind study of
controlled-release physostigmine for the treatment of symptoms secondary
to Alzheimer\'s disease. Physostigmine Study Group.* Neurology, 1996.
47(6): p. 1389-95. OBJECTIVE: A multicenter trial to evaluate the
efficacy of controlled-release physostigmine salicylate, a
cholinesterase inhibitor, was conducted in 1,111 mild-to-moderate
Alzheimer\'s disease (AD) subjects. DESIGN: During dose titration,
subjects received 18, 24, or 30 mg of physostigmine or placebo daily.
After a 2-week washout period, 366 subjects with putative improvement
were randomized to receive either placebo or their best dose of
physostigmine in a 6-week double-blind trial. Nonresponding patients
(439) were randomized to receive in a separate double-blind trial either
placebo or their highest tolerated dose of physostigmine. The primary
efficacy measures included the cognitive subscale of the Alzheimer
Disease Assessment Scale (ADAS) and a Clinical Global Impression of
Change (CGIC). Secondary measures included the Mini-Mental State
Examination and two activities-of-daily-living scales. RESULTS: At the
end of the 6-week double-blind phase, physostigmine-treated patients
scored 1.75 points higher than placebo-treated patients on the ADAS (p =
0.003) and 0.26 points higher on the CGIC (p = 0.012) in the
intent-to-treat analysis. There was no significant improvement on the
secondary outcome measures. Patients failing to respond to physostigmine
during the dose titration phase failed to respond on any of the outcome
measures during the double-blind period of re-exposure. Common adverse
events included nausea, vomiting, diarrhea, and anorexia. There were no
significant changes in liver function tests. CONCLUSION: This study
demonstrated statistically significant differences between physostigmine
and placebo on both a performance-based cognitive functioning instrument
and a clinician\'s global evaluation. The magnitude of the effect size
was small and occurred only in the subset of patients who responded in
the initial dose titration study period. Nevertheless, the results
suggest that in a subset of patients, physostigmine can induce a degree
of cognitive improvement over 6 weeks of treatment.

674\. Tune, L., *et al.*, *Physostigmine in Alzheimer\'s disease:
effects on cognitive functioning, cerebral glucose metabolism analyzed
by positron emission tomography and cerebral blood flow analyzed by
single photon emission tomography.* Acta Psychiatr Scand Suppl, 1991.
366: p. 61-5. The effect of acute, intravenous administration of
physostigmine on measures of brain activity and cognitive functioning
were investigated in 14 patients with Alzheimer\'s disease. Regional
cerebral glucose metabolism was assessed using
(18F)-fluoro-2-deoxy-D-glucose and positron emission tomography, and
cerebral blood flow was assessed using 123I-iodoamphetamine single
photon emission tomography. Although physostigmine enhanced cerebral
blood flow in most patients, only one patient showed significant
clinical improvement. This patient, however, also showed a very
pronounced improvement in cerebral glucose metabolism. It is concluded
that these preliminary findings hold considerable promise for our
appreciation of the pathophysiology of dementing illness as well as our
understanding of centrally acting compounds of interest in Alzheimer\'s
disease.

675\. Unni, L.K., *et al.*, *Determination of physostigmine in plasma
and cerebrospinal fluid by liquid chromatography with electrochemical
detection.* Clin Chem, 1989. 35(2): p. 292-5. Physostigmine (Phy) was
determined in plasma and cerebrospinal fluid (CSF) by HPLC with
electrochemical detection, with use of a normal-phase column and
methanolic sodium acetate buffer, pH 4.6. The detection limit of the
method was 0.5 micrograms/L for a 2-mL sample of plasma or 0.5 mL of
CSF. Analytical recovery of Phy in the range from 0.5 to 40 micrograms/L
was 60% (SD 5%) for plasma and 78% (SD 8%) for CSF. Excellent
chromatographic separation of Phy without column deterioration during
extended usage and constant recovery for a wide range of Phy
concentrations makes the routine monitoring of plasma from patients with
Alzheimer\'s disease economically feasible. Using our method, we
measured Phy in 13 such patients\' plasmas at 105 and 135 min after a
135-min intravenous infusion of 300, 600, and 900 micrograms of Phy per
square meter of body surface. Mean values significantly increased with
dose (P = 0.001), but differences between 105 and 135 min (P = 0.229) or
between dose and time (P = 0.949) were not significant.

676\. Wettstein, A., *No effect from double-blind trial of physostigmine
and lecithin in Alzheimer disease.* Ann Neurol, 1983. 13(2): p. 210-2.
Eight patients with clinically diagnosed mild to severe Alzheimer
disease were treated during two six-week periods by a double-blind,
single-crossover protocol with placebo or a combination of 18 gm of
lecithin and 3 to 10 mg of oral physostigmine daily. No improvement in
behavior, recent memory, or other neuropsychological functions occurred.

677\. Wirkowski, E., I. Prohovnik, and W.L. Young, *Observations on the
physostigmine syndrome in patients with Alzheimer\'s disease.* J
Neuropsychiatry Clin Neurosci, 1991. 3(1): p. 73-5. The authors present
two patients with Alzheimer\'s disease who each received a single
intravenous dose of physostigmine. Subjective complaints and mood
changes were disproportional with objectively verified physiological
side effects. Such observations may contribute to an understanding of
affective disorders and should receive more attention in future studies
of cholinesterase inhibitors.

678\. Zhang, J., *et al.*, *Development of a defined medium fermentation
process for physostigmine production by Streptomyces griseofuscus.* Appl
Microbiol Biotechnol, 1996. 44(5): p. 568-75. Physostigmine is a plant
alkaloid of great interest as a therapeutic candidate for the treatment
of Alzheimer\'s disease. Fortunately, this compound is also produced by
Streptomyces griseofuscus NRRL 5324 during submerged cultivation. A
fermentation process that used chemically defined medium was therefore
developed for its production. By means of statistical experimentation,
the physostigmine titer was quickly increased from 20 mg/l to 520 mg/l
with a culture growth of 19 gl dry cell weight on the shake-flask scale.
Further medium optimization resulted in a yield of 790 mg/l in a 23-1
bioreactor using a batch process. A titer of 880 mg/l was attained
during scale-up in a 800-1 fermentor by employing a nutrient-feeding
strategy. This production represents a 44-fold increase over the yield
from the initial process in shake-flasks. The defined-medium
fermentation broth was very amenable to downstream processing.

679\. Wester, P., *et al.*, *Monoamine metabolite concentrations and
cholinesterase activities in cerebrospinal fluid of progressive dementia
patients: relation to clinical parameters.* Acta Neurol Scand, 1988.
77(1): p. 12-21. Forty-five well clinically characterized patients with
progressive dementia were investigated for lumbar cerebrospinal fluid
(CSF) monoamine metabolites and cholinesterase activities. Monoamine
concentrations were determined by reverse phase liquid chromatography
with electrochemical detection and the cholinergic enzymes were measured
photometrically. Firstly, all clinical and CSF parameters were studied
in statistical cluster analyses to detect groups of variables which
demonstrated a high correlation with respect to each other. The CSF
transmitter markers were then used in multiple regression models to
explain the variance of clinical variables as chosen from the cluster
analyses. The degree of dementia, as assessed by global deterioration
score (GDS) and activity in daily life (ADL) status, as well as the
Alzheimer-related symptoms dyspraxia and dysphasia, were associated with
low AChE activities in CSF. A presumed subgroup of dementia patients
clinically characterized by asymmetry of neurological signs, increased
unilateral tonus, stepwise progression, and high Hachinski score, showed
low HVA concentrations in CSF. These data suggest a coupling of
clinical/neurological parameters to different CSF transmitter profils
and, thus, that CSF biochemical parameters are of use as antemortem
markers in dementia conditions.

680\. Yoshinaga, J., *et al.*, *\[Acetylcholinesterase activity in CSF
in senile dementia of Alzheimer type, vascular dementia, and
Parkinson\'s disease\].* Rinsho Shinkeigaku, 1989. 29(3): p. 376-8.
Acetylcholinesterase (AChE) activity was measured in cerebrospinal fluid
(CSF) from 25 patients with senile dementia of Alzheimer type (SDAT), 11
patients with vascular dementia (VD), 26 patients with Parkinson\'s
disease (PD), and 30 normal controls. AChE activity also was measured in
46 normal subjects whose ages ranged from 15 to 85 to evaluate the
effect of age on AChE activity. CSF AChE activity for the SDAT, VD and
PD groups showed no significant difference compared with the value for
the control group. However, there were significant decreases in CSF AChE
activity in the VD and PD groups with the development of ventricular
enlargement. There was no significant correlation between CSF AChE
activity decrease and ventricular enlargement in the SDAT group. AChE
activity increased significantly over the age range of 15 to 85. These
results suggest that, although CSF AChE activity is not a useful
parameter in the diagnosis of dementia, it may be a marker indicating
abnormalities of the intracerebral cholinergic system during the process
of cerebral atrophy.

681\. Tune, L., *et al.*, *Cerebrospinal fluid acetylcholinesterase
activity in senile dementia of the Alzheimer type.* Ann Neurol, 1985.
17(1): p. 46-8. Acetylcholinesterase (AChE) activity was measured in
cerebrospinal fluid (CSF) samples from 36 individuals, including 12
persons with Alzheimer\'s disease, 12 normal controls, and 12 patients
with other dementias. AChE activity also was measured in 47 normal
subjects whose ages ranged from 20 to 84 to evaluate the effect of age
on AChE activity. CSF from patients with senile dementia of the
Alzheimer type showed significantly lower mean AChE activity than in
age-matched controls and patients with other dementia syndromes. No
correlation was found between duration of illness, age, or severity of
illness (as measured by the Mini-Mental State Examination score) and CSF
AChE activity in Alzheimer\'s disease. AChE increased significantly over
the age range of 20 to 84. CSF AChE activity may prove to be a useful
diagnostic test to confirm the clinical diagnosis of moderate to severe
Alzheimer\'s disease.

682\. Soininen, H., T. Halonen, and P.J. Riekkinen,
*Acetylcholinesterase activities in cerebrospinal fluid of patients with
senile dementia of Alzheimer type.* Acta Neurol Scand, 1981. 64(3): p.
217-24. We have studied, as a possible marker of cholinergic neurons,
the acetylcholinesterase (AChE) activity in cerebrospinal fluid (CSF) of
21 SDA patients and 9 controls of similar age with no neurological
disease. The AChE activities were significantly lower in the SDA
patients compared to the controls. The AChE activities were also lowered
in the most severely demented patients compared to those who were less
severely demented but the difference was not statistically significant.
As a potential glia marker, beta-glucuronidase activity in CSF was
studied, but no significant difference was found in the activities of
the SDA patients compared to the controls. The reduced AChE activities
in the CSF of the SDA patients may be related to the loss of cholinergic
neurons or disturbed cholinergic metabolism in the brain.

683\. Sirvio, J. and P.J. Riekkinen, *Brain and cerebrospinal fluid
cholinesterases in Alzheimer\'s disease, Parkinson\'s disease and aging.
A critical review of clinical and experimental studies.* J Neural Transm
Park Dis Dement Sect, 1992. 4: p. 337-58. Acetylcholinesterase (AChE),
an enzyme responsible for the break-down of acetylcholine, is found both
in cholinergic and non-cholinergic neurons in the central nervous
system. In addition to its role in the catabolism of acetylcholine, AChE
have other functions in brain, e.g. in the processing of peptides and
proteins, and in the modulation of dopaminergic neurons in the brain
stem. Several clinical and experimental studies have investigated AChE
in brain and cerebrospinal fluid (CSF) in aging and dementia. The
results suggest that brain AChE and its molecular forms show interesting
changes in dementia and aging. However, CSF-AChE activity is not a very
reliable or sensitive marker of the integrity and function of
cholinergic neurons in the basal forebrain complex. Additional work is
needed to clarify the role of AChE abnormality in the formation of
pathology changes in patients with Alzheimer\'s disease.

684\. Sirvio, J., *et al.*, *Cholinesterases in the cerebrospinal fluid,
plasma, and erythrocytes of patients with Alzheimer\'s disease.* J
Neural Transm, 1989. 75(2): p. 119-27. In patients with probable
Alzheimer\'s disease and in controls, acetyl- and butyrylcholinesterase
activities were studied in cerebrospinal fluid (CSF) and plasma, and
acetylcholinesterase activity of erythrocytes was determined. In
addition, the molecular forms of acetylcholinesterase were measured in
CSF. Severely demented patients had significantly lower
acetylcholinesterase (p less than 0.01) and butyrylcholinesterase (p
less than 0.05) activities in CSF than the controls had, but the
activities of these enzymes in plasma and erythrocytes were within the
same range in both groups. Acetylcholinesterase and
butyrylcholinesterase activities in the CSF of mildly demented patients
did not differ from control values. The ratio of the intermediate
molecular form of acetylcholinesterase to the light molecular form of
the enzyme did not differ significantly between patients with
Alzheimer\'s disease and controls. According to our results, AChE levels
were lower in the CSF of severely demented patients, but both light and
intermediate molecular forms were affected.

685\. Saez-Valero, J., *et al.*, *Changes in molecular isoform
distribution of acetylcholinesterase in rat cortex and cerebrospinal
fluid after intracerebroventricular administration of amyloid
beta-peptide.* Neurosci Lett, 2002. 325(3): p. 199-202. Previous studies
have shown that an abnormal salt-soluble form of G(1)
acetylcholinesterase (AChE) is increased in the Alzheimer\'s disease
(AD) brain. The aim of the present study was to examine changes in AChE
activity in an in vivo model of beta-amyloid peptide (A beta)
administration. Rats received intracerebroventricular injections of A
beta(25-35) (20 microg/day for seven days). Levels of AChE were measured
in cerebral cortex and cerebrospinal fluid (CSF) after two months. A
beta(25-35) administration did not alter total AChE activity in the
cerebral cortex or CSF. However, analysis of salt-extractable AChE
isoforms revealed an increase in the proportion of G(1) in both cortex
and CSF, similar to that previously observed in AD patients. The results
support the view that changes in AChE isoform pattern in the AD brain
are a direct consequence of A beta accumulation.

686\. Saez-Valero, J. and D.H. Small, *Altered glycosylation of
cerebrospinal fluid butyrylcholinesterase in Alzheimer\'s disease.*
Brain Res, 2001. 889(1-2): p. 247-50. Our previous studies have shown
that a minor isoform of acetylcholinesterase (AChE) is increased in the
cerebrospinal fluid (CSF) of Alzheimer\'s disease (AD) patients. In the
present study, the glycosylation of butyrycholinesterase (BuChE) was
found to be altered in AD CSF. By combining an analysis of CSF AChE and
BuChE glycosylation, it is possible to identify cases of AD with more
than 90% sensitivity and specificity.

687\. Saez-Valero, J., *et al.*, *Altered glycosylation of
acetylcholinesterase in lumbar cerebrospinal fluid of patients with
Alzheimer\'s disease.* J Neurol Neurosurg Psychiatry, 2000. 69(5): p.
664-7. As clinical diagnosis of Alzheimer\'s disease is only 80%-90%
accurate, there is a need to identify biochemical markers of
Alzheimer\'s disease. Previous studies have shown an abnormality in the
glycosylation of acetylcholinesterase (AChE) in the CSF collected
postmortem from patients with Alzheimer\'s disease. This abnormality was
very specific for Alzheimer\'s disease, as it was not detected in other
illnesses causing dementia. We report here that the glycosylation of
AChE is also altered in lumbar CSF collected antemortem. The altered
glycosylation was due to increased concentrations of a minor AChE
isoform that does not bind to concanavalin A (Con A). Glycosylation of
AChE may eventually be of diagnostic value, especially when used in
combination with other CSF markers.

688\. Saez-Valero, J., S.S. Mok, and D.H. Small, *An unusually
glycosylated form of acetylcholinesterase is a CSF biomarker for
Alzheimer\'s disease.* Acta Neurol Scand Suppl, 2000. 176: p. 49-52. The
identification of a biochemical marker of Alzheimer\'s disease (AD) is a
major research aim of many groups. Abnormal levels of tau and Abeta have
been identified in the cerebrospinal fluid (CSF) of AD patients,
although the sensitivity and specificity of the changes in these two
biomarkers alone is not sufficient to be of diagnostic value. Recently,
our group has identified an abnormality in the glycosylation of
acetylcholinesterase (AChE). The increase in this glycoform of AChE is
very specific for Alzheimer\'s disease and is not seen in many other
neurological diseases including other dementias.

689\. Saez-Valero, J., *et al.*, *Molecular isoform distribution and
glycosylation of acetylcholinesterase are altered in brain and
cerebrospinal fluid of patients with Alzheimer\'s disease.* J Neurochem,
1999. 72(4): p. 1600-8. The glycosylation of acetylcholinesterase (AChE)
in CSF was analyzed by lectin binding. AChE from Alzheimer\'s disease
(AD) patients was found to bind differently to two lectins, concanavalin
A and wheat germ agglutinin, than AChE from controls. As multiple
isoforms of AChE are present in both CSF and brain, we examined whether
the abnormal glycosylation of AD AChE was due to changes in a specific
molecular isoform. Globular amphiphilic dimeric (G2a) and monomeric
(G1a) isoforms of AChE were found to be differentially glycosylated in
AD CSF. Glycosylation of AChE was also altered in AD frontal cortex but
not in cerebellum and was also associated with an increase in the
proportion of light (G2 and G1) isoforms. This study demonstrates that
the glycosylation of AChE is altered in the AD brain and that changes in
AChE glycosylation in AD CSF may reflect changes in the distribution of
brain isoforms. The study also suggests that glycosylation of AChE may
be a useful diagnostic marker for AD.

690\. Ruberg, M., *et al.*, *Acetylcholinesterase and
butyrylcholinesterase activity in the cerebrospinal fluid of patients
with neurodegenerative diseases involving cholinergic systems.* J Neurol
Neurosurg Psychiatry, 1987. 50(5): p. 538-43. Acetylcholinesterase
(AChE) and butyrylcholinesterase (BChE) were assayed in the
cerebrospinal fluid (CSF) of subjects with neurodegenerative diseases
(dementing and non-dementing, with and without known cholinergic
lesions), to determine whether CSF AChE is a valid marker of central
cholinergic activity. The relative proportions of the different forms of
each enzyme and of AChE to BChE were similar in CSF and brain. AChE
decreased in Huntington\'s chorea (degeneration of striatal cholinergic
interneurons) but also in multiple sclerosis (not known to affect
cholinergic systems). BChE paralleled AChE, although the enzymes were
dissociated in some patients. It is concluded that CSF AChE activity may
globally reflect brain AChE, but pathology-induced changes may not be
directly reflected.

691\. Pearlson, G.D. and L.E. Tune, *Cerebral ventricular size and
cerebrospinal fluid acetylcholinesterase levels in senile dementia of
the Alzheimer type.* Psychiatry Res, 1986. 17(1): p. 23-9. Computed
tomography (CT) was performed in 16 patients with a diagnosis of senile
dementia of the Alzheimer type (SDAT). CT scans were rated without
knowledge of clinical and laboratory data, and lateral ventricle-brain
ratios (VBRs) calculated. Cerebrospinal fluid (CSF) acetylcholinesterase
(AChE) activity was measured by radioenzymatic assay in all patients,
and degree of dementia quantified using the Mini-Mental State
Examination (MMSE). There were significant correlations between cerebral
atrophy as assessed by VBR and CSF AChE activity. Cognitive impairment
on MMSE also correlated significantly with VBR. These correlations were
not accounted for by age, dilutional effects, or duration of illness.
The relationship between VBR and AChE activity demonstrates an
association between two independently determined pre-mortem measures of
illness.

692\. Navaratnam, D.S., *et al.*, *Anomalous molecular form of
acetylcholinesterase in cerebrospinal fluid in histologically diagnosed
Alzheimer\'s disease.* Lancet, 1991. 337(8739): p. 447-50. The
possibility that the different molecular forms of acetylcholinesterase
(AChE) in cerebrospinal fluid (CSF) which can be revealed by isoelectric
focusing may reflect changes in AChE in pathologically affected neurons
in Alzheimer\'s disease was tested in a retrospective study. CSF samples
obtained at necropsy from 33 patients with clinically diagnosed
dementia, 9 with possible dementia, and 19 without a diagnosis of
dementia were examined by isoelectric focusing. An additional band
indicating an anomalous molecular form of AChE was present in CSF from
19 of 23 patients with a histological diagnosis of Alzheimer\'s disease
and no other central nervous system disorder but in none of the 19
non-demented patients (without a histological diagnosis of Alzheimer\'s
disease). The band was also present in 2 of 8 patients with
histologically defined Alzheimer\'s disease plus other neurological
disorders and in 4 of 8 patients with possible dementia who did not meet
histopathological criteria for Alzheimer\'s disease. The absence of the
anomalous form of AChE from the CSF of non-demented patients and its
presence in the CSF of the majority of patients with Alzheimer\'s
disease has implications for our understanding of the biological basis
of the disease and might form the basis of an antemortem diagnostic
test.

693\. Nakano, S., *et al.*, *Acetylcholinesterase activity in
cerebrospinal fluid of patients with Alzheimer\'s disease and senile
dementia.* J Neurol Sci, 1986. 75(2): p. 213-23. Acetylcholinesterase
(AChE) in the cerebrospinal fluid (CSF) from patients with
Alzheimer-type dementia and control subjects was analyzed by
centrifugation on a sucrose density gradient, and by column
chromatography on Sephadex G-200. The sedimentation coefficient and
molecular weight of CSF AChE were calculated as 10S and 380,000,
respectively, which corresponded to those of G4 isozyme in the brain.
Other isozymes of AChE were not detected in the CSF of either patients
with Alzheimer-type dementia or the controls. Sufficient activity of
AChE was observed in the CSF of a patient with familial
pseudocholinesterase deficiency, although the pseudocholinesterase
activity was not found either in the serum or in the CSF. CSF AChE
activity in control subjects increased with advancing age (P less than
0.02). AChE activity in the CSF was significantly lower in patients with
presenile dementia (Alzheimer\'s disease), compared with age-matched
control subjects (P less than 0.001). However, AChE activity in the CSF
showed a wide variation among patients of Alzheimer-type dementia with a
late onset (senile dementia).

694\. Marquis, J.K., *et al.*, *Cholinesterase activity in plasma,
erythrocytes, and cerebrospinal fluid of patients with dementia of the
Alzheimer type.* Biol Psychiatry, 1985. 20(6): p. 605-10.
Cholinesterases, including pseudocholinesterase (BChE) of human plasma
and acetylcholinesterase (AChE) of erythrocytes and cerebrospinal fluid
(CSF), have been considered as possible markers in dementia of the
Alzheimer type (DAT). Reported data, however, are widely varied, and no
significant pattern emerges when total enzyme activity is assayed. In
the present studies, we have reexamined the relationship of ChE
activities in DAT and control patients. ChE activity was measured in
plasma, erythrocytes, and CSF from DAT patients and compared with normal
controls as well as with samples from patients with a diagnosis other
than DAT. Early age onset (presenile) and late age onset (senile) DAT
were also compared. No significant differences in total enzyme activity
were found in any of the comparisons. Calculations of AChE/BChE ratios
in CSF also provided no significant indication of any changes in ChE
activities in DAT. It is suggested that measurements of total AChE or
BChE activity in these biological materials do not provide a useful
index of alterations in central cholinergic function in patients with
DAT.

695\. Kumar, V., E. Giacobini, and S. Markwell, *CSF choline and
acetylcholinesterase in early-onset vs. late-onset Alzheimer\'s disease
patients.* Acta Neurol Scand, 1989. 80(5): p. 461-6. Cerebrospinal fluid
acetylcholinesterase (AChE) activity levels and choline (Ch) levels were
studied in 52 dementia of Alzheimer type (DAT) patients and 20
age-matched controls. The AChE activity was significantly lower and Ch
levels were significantly higher in DAT patients than the age-matched
controls. There was no significant difference in AChE activity and Ch
levels between early-onset (less than or equal to 65 years) patients and
late-onset (greater than 65 years) patients. However, the AChE activity
was significantly lower in early-onset patients compared with their
age-matched controls but no difference was observed in late-onset
patients compared with their age-matched controls. None of the
biological measures (AChE, Ch) were significantly correlated with the
degree of cognitive impairment, duration of the illness or the sex of
these patients.

696\. Kumar, V. and E. Giacobini, *Cerebrospinal fluid choline, and
acetylcholinesterase activity in familial vs. non-familial Alzheimer\'s
disease patients.* Arch Gerontol Geriatr, 1988. 7(2): p. 111-7.
Acetylcholinesterase (AChE) and choline (Ch) in the cerebrospinal fluid
(CSF) from familial and non-familial Alzheimer disease patients were
studied. The choline level was significantly less (p less than 0.04) in
familial patients than in non-familial patients. However, there was no
difference in AChE activity in these two groups.

697\. Konings, C.H., *et al.*, *Cerebrospinal fluid acetylcholinesterase
homospecific activity in patients with \"probable Alzheimer\'s
disease\".* Biol Psychiatry, 1994. 36(10): p. 708-9. .

698\. Konagaya, M., Y. Konagaya, and M. Iida, *\[CSF
acetylcholinesterase activity in central neurological diseases involving
cholinergic systems\].* Rinsho Shinkeigaku, 1992. 32(3): p. 266-71. The
enzymatic activity of acetylcholinesterase (AchE) in the cerebrospinal
fluid (CSF) is considered to be a marker of central cholinergic neuron
integrity. Then, we evaluated CSF AchE activity in 90 cases of
neurological diseases involving cholinergic system and their related
disease, and 28 control cases without central organic lesions or
abnormal findings in routine CSF study. AchE activity was evaluated
according to Ellman\'s method using acetylthiocholine iodide as a
substrate and tetraisopropyl-pyrophosphoramide, a specific inhibitor of
butyrylocholinesterase. CSF AchE of Alzheimer type dementia (AD/SDAT, N
= 12: 21.9 +/- 4.7 nmol/ml/min) showed no significant change from those
of both control group (22.1 +/- 3.9) and vascular dementia (9: 21.7 +/-
6.7). In extrapyramidal diseases, reduction of the activity was observed
in Huntington\'s chorea (HC, 4: 16.3 +/- 1.4) and progressive
supranuclear palsy (PSP, 4: 17.6 +/- 1.7), whereas normal activity was
shown in Parkinson\'s disease (PD, 19: 22.5 +/- 4.6),
dentatorubropallidoluysian atrophy (DRPLA, 4: 22.6 +/- 4.2) and
striatonigral degeneration (SND, 4: 20.4 +/- 4.3). In
olivopontocerebellar atrophy (OPCA, N = 16), we disclosed reduced CSF
AchE activity (15.8 +/- 2.4) which had significant correlations with the
atrophy of the pontine base (r = 0.6017, p less than 0.02) and
cerebellar vermis (r = 0.5450, p less than 0.05) in MRI. AchE activity
in cerebellar cortical atrophy (CCA, 5: 20.6 +/- 2.2) remained within
the control values. Normal activity was demonstrated in both amyotrophic
lateral sclerosis (6: 24.3 +/- 7.3) and spinal muscular atrophy (4: 22.9
+/- 3.9).(ABSTRACT TRUNCATED AT 250 WORDS).

699\. Huff, F.J., C.T. Reiter, and J. Protetch, *Activities and kinetic
properties of lumbar cerebrospinal fluid cholinesterases in relation to
clinical diagnosis, severity, and progression of Alzheimer\'s disease.*
Can J Neurol Sci, 1989. 16(4): p. 406-10. Acetylcholinesterase (AChE)
and butyrylcholinesterase (BChE) activities of lumbar cerebrospinal
fluid (CSF) have been measured in seventeen patients with a clinical
diagnosis of probable Alzheimer\'s disease (Prob AD), possible
Alzheimer\'s disease (Poss AD), or dementia of non-Alzheimer aetiology
(Non-AD). The three diagnostic groups did not differ with regard to the
Km or saturation kinetic properties of AChE and BChE. The CSF AChE
activity was significantly higher in Prob AD than in Non-AD patients.
The groups did not differ significantly in BChE activity. The ratio of
AChE to BChE activity was significantly higher in both the Prob AD and
Poss AD groups than in the Non-AD group, and the ranges of values in the
Prob AD and Non-AD groups did not overlap. Among patients in the Prob AD
group, severity of dementia was correlated with both AChE activity and
the AChE/BChE ratio, and progression of dementia over time was also
correlated with AChE/BChE. The AChE/BChE ratio correlated more strongly
than AChE with severity and progression of dementia in Prob AD patients,
and also better distinguished them from Non-AD patients, suggesting that
AChE/BChE may be the more useful marker for diagnosis of AD. It is not
clear from the results whether AChE/BChE is useful for diagnosis of the
complex dementia cases in the Poss AD group.

700\. Huff, F.J., *et al.*, *Cholinesterases in cerebrospinal fluid.
Correlations with clinical measures in Alzheimer\'s disease.* J Neurol
Sci, 1986. 72(2-3): p. 121-9. Acetylcholinesterase and
butyrylcholinesterase activities in cerebrospinal fluid were measured in
17 patients with Alzheimer\'s disease and 6 control patients, as
potential clinical measures of impaired cholinergic neurotransmission in
Alzheimer\'s disease. The activity of butyrylcholinesterase was
decreased in patients with Alzheimer\'s disease compared to that
observed in control patients, but there was overlap between values in
the 2 groups. Low butyrylcholinesterase activity was correlated with
severity of dementia, memory impairment, and language disorder.
Acetylcholinesterase activity was significantly correlated with visual
contrast sensitivity, but not with dementia severity, and did not
differentiate patients with Alzheimer\'s disease from control cases.
These results suggest that cholinesterases in cerebrospinal fluid are
related to brain cholinesterases, and indicate that the activities of
acetylcholinesterase and butyrylcholinesterase should be distinguished
in studies of cerebrospinal fluid.

701\. Fodero, L.R., *et al.*, *Altered glycosylation of
acetylcholinesterase in APP (SW) Tg2576 transgenic mice occurs prior to
amyloid plaque deposition.* J Neurochem, 2002. 81(3): p. 441-8. Previous
studies have shown that a minor glycoform of acetylcholinesterase (AChE)
is increased in Alzheimer\'s disease brain and cerebrospinal fluid. This
glycoform can be distinguished from other AChE species by its lack of
binding to concanavalin A (Con A). In this study, the temporal
relationship between AChE glycosylation and Abeta deposition was
examined in Tg2576 mice. There was a significant (p \< 0.05) difference
in AChE glycosylation in Tg2576 mice compared with age-matched
background strain control mice at 4 months of age. This difference in
glycosylation was also observed in 8- and 12-month-old Tg2576 mice. In
contrast, Abeta plaques were only seen in the Tg2576 mice at 12 months
of age, and were not detected at 4 and 8 months of age. Soluble
human-sequence Abeta was detected as early as 4 months of age in the
transgenic mice. The altered AChE glycosylation was due to an increase
in a minor AChE isoform, which did not bind Con A, similar to that
previously observed to be increased in Alzheimer\'s disease brain and
cerebrospinal fluid. The results demonstrate that in transgenic mice
altered AChE glycosylation is associated with very early events in the
development of AD-like pathology. The study supports the possibility
that glycosylation may also be a useful biomarker of AD.

702\. Elble, R., E. Giacobini, and G.F. Scarsella, *Cholinesterases in
cerebrospinal fluid. A longitudinal study in Alzheimer disease.* Arch
Neurol, 1987. 44(4): p. 403-7. We measured acetylcholinesterase (AChE)
and butyrylcholinesterase activities in the lumbar cerebrospinal fluid
(CSF) of 39 patients with dementia of Alzheimer type and 21 age-matched
controls. The mean lumbar CSF AChE activity in our patients did not
differ significantly from that of controls. The 7S and 11S molecular
forms were also unchanged. When CSF was analyzed at six-month intervals,
there was no significant decline in AChE activity over a span of 12
months. Our results and those of previous studies demonstrate that CSF
AChE is not a useful diagnostic marker of Alzheimer disease.

703\. Deutsch, S.I., *et al.*, *Acetylcholinesterase activity in CSF in
schizophrenia, depression, Alzheimer\'s disease and normals.* Biol
Psychiatry, 1983. 18(12): p. 1363-73. Acetylcholinesterase (AChE)
activity and protein were measured in the CSF of patients with
Alzheimer\'s disease, depression, schizophrenia with and without tardive
dyskinesia, and control subjects. AChE activity was assayed by a
radioenzymatic method involving the direct extraction of hydrolyzed
3H-acetate into a toluene-based scintillation fluid followed by liquid
scintillation spectrometry. AChE activity was proportional to the amount
of CSF protein. Greater than 90% of AChE activity in CSF could be
inhibited by 10(-3) M eserine. In addition, activity remained stable
despite repeated freeze-thawing in an acetone-dry ice bath. Age was
found to be positively correlated with CSF protein and AChE activity
expressed per volume CSF, but not with AChE measured per milligram
protein. No differences between diagnostic groups were found on either
measure of AChE when the extraneous factors of age and CSF protein
concentrations were controlled, nor were any differences found between
groups for CSF protein when age was controlled.

704\. Atack, J.R. and M.B. Schapiro, *Inositol monophosphatase activity
in normal, Down syndrome and dementia of the Alzheimer type CSF.*
Neurobiol Aging, 2002. 23(3): p. 389-96. Inositol monophosphatase
(IMPase), a cytoplasmic enzyme that hydrolyses inositol monophosphates
to produce inositol is also found in the cerebrospinal fluid (CSF).
Since levels of inositol have been previously reported to be elevated in
Down syndrome (DS) CSF, IMPase activity was measured in CSF of DS
subjects to establish whether altered inositol levels may be related to
changes in IMPase activity. In addition, and to better understand the
regulation of IMPase expression in the CSF, enzyme activity was measured
in normal aging, patients with Alzheimer-type or multi-infarct dementia
(DAT and MID, respectively) and in CSF obtained by repeat lumbar
puncture or from sequential aliquots of CSF from along the rostro-caudal
axis. IMPase activity was relatively constant in CSF obtained from
repeated lumbar puncture and there was no significant rostro-caudal
gradient of activity in either normal or DS subjects, indicating that
the enzyme originates from both brain and spinal cord. Compared to
respective age-matched normal subjects, CSF IMPase activity was
unaltered in DS, DAT and MID. However, in normal volunteers there was a
significant positive correlation between age and CSF IMPase activity.
Furthermore, there were significant correlations between CSF IMPase
activity and acetylcholinesterase and butyrylcholinesterase activities
and total protein, suggesting co-regulation of these parameters within
the CSF.

705\. Atack, J.R., *et al.*, *Cerebrospinal fluid cholinesterases in
aging and in dementia of the Alzheimer type.* Ann Neurol, 1988. 23(2):
p. 161-7. Protein concentration and acetylcholinesterase (AChE) and
butyrylcholinesterase (BChE) activities were assayed in the
cerebrospinal fluid (CSF) of 26 healthy normal subjects (20-86 years
old), 27 patients with dementia of the Alzheimer type (DAT), and 10
patients with dementia of the Alzheimer type with extrapyramidal signs
(EDAT). In normal subjects, there was an age-related increase in CSF
protein and AChE activity and a significant correlation (p less than
0.001) between CSF protein and BChE activity. In the DAT and EDAT
groups, CSF AChE activities (mean +/- SD = 17.5 +/- 3.6 and 15.3 +/- 4.4
nmol/min/ml, respectively) were significantly lower (p less than 0.05)
than in 13 age-matched control subjects (21.5 +/- 5.6 nmol/min/ml). In
contrast, neither CSF protein concentration, BChE activity, nor the
ratio of AChE/BChE differed significantly between groups. In patients
with DAT, CSF AChE activity was significantly lower (p less than 0.05)
in subjects with an early onset compared to those with a late onset
(16.4 +/- 3.4 and 19.7 +/- 2.8 nmol/min/ml, respectively), and activity
in the latter group did not differ significantly from control values.
CSF AChE activity was not related to dementia severity and did not
change significantly over an 18-month period. Although these results
confirm a cholinergic deficit in patients with DAT, the considerable
overlap of CSF AChE activity between groups and the nonsignificant
correlation between AChE activity and dementia severity limit the
usefulness of CSF AChE as a diagnostic marker of this disorder.