bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of somatostatin on parathyroid hormone levels and on responses of parathyroid hormone to β-adrenergic agonists and hypocalcaemia
Authors: Blum J. W. , Fischer J. A.
Published: December 2008

Experiments were designed to study the effect of exogenous somatostatin (S) on basal levels or parathyroid hormone (PTH) and on PTH responses to isoproterenol (ISO), adrenaline (A) or ethyleneglycol-bis (β-aminoethylether) N,N'-tetraacetate (EGTA) in cattle. During S infusions (6.11 nmol injected iv as a bolus and 0.82 nmol/kg/min infused iv for 30 or 60 min) plasma levels of PTH and calcium (Ca) did not change, whereas concentrations of immunoreactive insulin (IRI) decreased significantly (P < 0.01). In response to ISO (0.09 nmol/kg/min) or EGTA (5.6 μmol/kg/min, depressing plasma Ca by 0.27 nmol/l) PTH levels were similarly increased (P < 0.05) both in the absence and presence of S. On the other hand, S supressed IRI responses to ISO. During 60-min infusions of EGTA (3.15 μmol/kg/min) plasma Ca fell to significantly lower levels (P < 0.01) during simultaneous infusions of S than in the absence of exogenous S, while the magnitude of PTH responses was similar. The results do not support a role of somatostatin on basal PTH levels and on PTH responses to β-adrenergic agonists or hypocalcaemia under conditions, in which S markedly lowers IRI levels and IRI responses to ISO. However, S apparently reduces Ca mobilisation during abrupt hypocalcaemia.
Ontogeny of circulating gastrin and pancreatic polypeptide in the foetal sheep
Authors: Shulkes Arthur , Hardy Kenneth J.
Published: December 2008

Hypoacidity and hypergastrinaemia are reported in the newborn human. To investigate the ontogeny of gastrin, plasma gastrin concentrations were measured in chronically cannulated foetal sheep from 100 days gestation to term (145 days) and up to 16 days following delivery. Plasma pancreatic polypeptide (PP) concentrations were measured as a marker of vagal activity. Compared with adult values, foetal plasma gastrin concentration was low at 101–105 days, being 7 ± 1 pmol/l (mean ± sem) but was greater than adult values from 130 days gestation and increased to 47 ± 5 at 141–145 days, and 90 ± 13 at 1–5 days post-partum. Maternal plasma gastrin levels during these periods ranged between 21 and 29 pmol/l and was not related to gestational age. Similarly, maternal plasma PP levels, which varied between 220 and 400 pmol/1, did not correlate with gestational age and did not differ significantly from non-pregnant sheep. Foetal plasma PP was low, 20 ± 3 at 101–105 days, rose to 92 ± 17 at 141–145 days, and increased to adult levels in the first week post-partum. Basal foetal and maternal plasma PP were inhibited by iv atropine injection. The increase in plasma PP may represent a maturity of vagal influence. Gastrin and PP have a trophic action on the gastro-intestinal tract, so the observation of significant levels of circulating gastrin and PP in the foetus suggests that they may be involved in maturation of the gastro-intestinal tract.
ACTH suppression after oral administration of cortisone in Addisonian and adrenalectomized patients
Authors: Aanderud Sylvi , Myking Ole Langeland , Bassøe Hans H.
Published: December 2008

Plasma cortisol and the corresponding ACTH concentrations were determined before, and for 6 h following a single oral dose of 25 mg cortisone acetate in 7 patients with Addison's disease, 6 patients adrenalectomized for Cushing's disease and 1 patient adrenalectomized for congenital adrenal hyperplasia. The basal plasma cortisol concentrations 12 h after an evening dose of cortisone acetate 12.5 mg were below 100 nmol/l, and the corresponding ACTH concentrations were markedly elevated in all the patients. Great interindividual variations were found in cortisol peak concentrations (Cmax) and the time to peak values, but without significant differences between the two patient groups. The maximal ACTH suppression occurred within 60–330 min after the cortisol Cmax. and was not significantly different in the two groups. The suppressed plasma ACTH concentrations were considerably above normal in 3 of the patients with Addison's disease and in 4 of the 6 patients adrenalectomized for Cushing's disease, including 2 patients with Nelson's syndrome.

A similar degree of impaired ACTH suppression in patients with Addison's disease as in adrenalectomized patients suggests the occurrence of a secondary hypothalamic-pituitary dysfunction with ACTH hypersecretion in Addison's disease. The adequacy of the commonly used adrenocortical replacement therapy and its possible relation to the impaired ACTH suppression is discussed.
Demonstration of γ-trace in normal endocrine cells of the adrenal medulla and in phaeochromocytoma
Authors: Löfberg H. , Nilsson K. E. , Strömblad L.-G. , Lasson Å. , Olsson S.-O.
Published: December 2008

γ-Trace was demonstrated by the immunohistochemical peroxidase/anti-peroxidase technique to occur in normal chromaffin cells of the adrenal medulla from African green monkey, capuchin monkey and beagle dog and in the cells of a norepinephrine-producing human phaeochromocytoma. The presence of γ-trace in the endocrine epithelial cells of the adrenal medulla suggests that γ-trace might be related to the neuroendocrine system.
A comparison of metabolic clearance rates of oestradiol-17β in immature and peripubertal female pigs and possible implications for the onset of puberty
Authors: Elsaesser F. , Stickney K. , Foxcroft G.
Published: December 2008

A continuous infusion technique of either [3H]oestradiol-17β (E2) or unlabelled E2 was used to investigate suggested differences in the metabolic clearance rate of oestradiol-17β (MCR-E2) in immature and peripubertal female pigs. Using the isotope infusion technique, the following values were obtained: 60 day old gilts; MCR-E2 = 2133 ± 274 ([unk] ± sem) ml/min, MCR-E2/kg BW = 116 ± 14.5 ml/min kg, and conversion ratio (CR) of E2 to oestrone (E1) = 31.6 ± 3.7%. The respective values for 160 day old gilts were: MCR-E2 = 3027 ± 340, MCR-E2/kg BW = 48.5 ± 4.82, and CR = 15.9 ± 2.12. Except for a significant difference in the weight related MCR-E2 data for the 60 day old group, similar values were found following infusion of unlabelled E2. The percentage of radioactivity extractable with ether from plasma was 22.6 ± 3.0% and 27.2 ± 2.0%. Fifty-seven and 66% of total radioactivity infused was recovered in the urine within 12 h in 60 and 160 day old gilts, respectively. There was no difference in the percentage binding of E2 to plasma proteins as determined by equilibrium dialysis (80%). It is concluded that in addition to an activation of ovarian steroidogenesis during puberty, a gradual maturational decrease in the MCR-E2/kg BW might play a role in raising plasma E2 concentrations and thus in constituting an effective oestrogen feedback signal, which results in the first pre-ovulatory LH-surge.
The effect of hyposmotic and sodium chloride hyperosmotic environments on the secretion and synthesis of prolactin from human decidua in vitro
Authors: Andersen Jesper Rye , Borggaard Birgit , Ørnvold Kim , Knoth Mogens
Published: December 2008

Using a paired design as well as a cross-over design both with 16 h incubation periods, we have incubated human decidua in hyposmotic, isosmotic, and sodium chloride hyperosmotic media. In the cross-over design each tissue aliquot was subjected to 3 media with different osmolalities, one of which was isosmotic. Thus, intensive utilization of the tissue was possible.

The results of the cross-over study were identical with the result of the paired design. We found a decreased secretion of prolactin in hyposmotic environments, whereas hyperosmotic environments up to an osmolality about 400 mmol/kg gave a dose related increase in the prolactin secretion into the medium as well as in the total content of prolactin in the tissue and the medium. Excessive hyperosmotic medium decreased the secretion. The enhanced secretion was an effect of increased production, which could be blocked by cycloheximide. We found no feedback of prolactin on its own secretion.
Endogenous androgen levels in epithelium and stroma of human benign prostatic hyperplasia and normal prostate
Authors: Bartsch W. , Krieg M. , Becker H. , Mohrmann J. , Voigt K. D.
Published: December 2008

5α-Dihydrotestosterone (DHT) and 5α-androstane-3α, 17β-diol (3α-diol) were extracted from epithelium and stroma of human benign prostatic hyperplasia (BPH) and of normal prostate and quantified by RIA. The main results were: (1) concerning the BPH, DHT is mainly located in the nuclear fraction of epithelium and stroma, whereas 3α-diol was completely of extranuclear origin, (2) in the nuclei derived from BPH stroma the DHT content (7.1 ± 0.88 pmol/mg DNA, mean ± sem [n = 14]) was significantly higher (P < 0.01) than in the nuclei derived from BPH epithelium (3.8 ± 0.38 pmol/ mg DNA [n = 14]). The DHT content in the nuclear fraction derived from unseparated, i.e. whole tissue, was 5.6 ± 0.60 pmol/mg DNA [n = 14], (3) the biological significance of the overwhelming DHT accumulation in the stromal nuclei for the BPH tissue is reflected by a significant correlation between the DHT values in the nuclei from stroma and whole tissue (rs = 0.710, P < 0.01) and (4) in four normal prostates the DHT content in the nuclear fraction of epithelium (1.3 ± 0.37 pmol/mg DNA) and stroma (2.2 ± 0.93 pmol/mg DNA) was significantly lower (P < 0.01, each) compared with the respective BPH fraction. These data support earlier findings which indicate that the stroma of BPH is a preferential tissue for androgen metabolism.
Dynamics of Prl release in galactorrhoeic normoprolactinaemic women
Authors: D'Agata R. , Aliffi A. , Maugeri G. , Mongioì A. , Vicari E. , Gulizia S.
Published: December 2008

Prl responsiveness to TRH and sulpiride was evaluated in 14 galactorrhoeic normoprolactinaemic women. Radiological signs of sellar alteration were present in 6 of these patients. Pituitary responses to TRH did not differ from those obtained in a group of 16 healthy women. Serum Prl levels after sulpiride were higher in the patients than in the controls (P<0.01). The Amax response was 256 ± 16 SE vs 158 ± 10.6 ng/ml in the control group (P<0.01). The mean integrated area after sulpiride was also greater (20738 ± 1263 se ng/ml/2 h vs 13 188 ± 408) (P< 0.01).

The markedly enhanced Prl response to sulpiride in our patients with galactorrhoea could be due to a functional disorder of the hypothalamic-pituitary axis or to a lactotrope hyperplasia.
Circulating TSH-binding inhibiting immunoglobulins in myasthenia gravis
Authors: Kiessling W. R. , Finke R. , Kotulla P. , Schleusener H.
Published: December 2008

Using a radioligand receptor assay the sera of 46 patients with myasthenia gravis (MG) were tested for the presence of circulating TSH-binding inhibiting immunoglobulins (TBII). In addition thyroid function was evaluated on the basis of T3, T4, TBG and TSH radioimmunoassays including the TRH stimulation test. Circulating antimicrosomal and antithyroglobulin thyroid antibodies were measured by haemagglutination techniques. Two patients had concomitant Graves' disease (GD), 5 were euthyroid with autonomously functioning thyroid tissue due to non-immunogenic multinodular goitre and 39 myasthenic patients were euthyroid with normal pituitary thyroid axis. Only 1 patient with GD had strongly positive TBII-activity and 3 euthyroid MG patients were TBII borderline-positive.
Inhibition by early treatment with bromocriptine of spontaneous mammary tumour development in rats with no side-effects
Authors: Nagasawa H. , Morii S.
Published: December 2008

Temporary inhibition by CB-154 (bromocriptine) of pituitary prolactin secretion, which induced a decline in mammary gland DNA synthesis for 4–11 weeks of age, resulted in a marked suppression of spontaneous mammary tumour development in rats after one year of age. The treatment had no effect on reproduction and subsequent lactation immediately after the CB-154 injection or growth and function of the mammary glands and pituitary prolactin secretion in later life.
Dopaminergic suppression of pancreatic somatostatin secretion
Authors: Itoh Mitsuyasu , Furman Brian L. , Gerich John E.
Published: December 2008

To characterize dopaminergic influences on pancreatic islet D cell function and its potential interaction with islet A and B cell function, the effect of dopamine (0.5–100 μm) on immunoreactive somatostatin (IRS), insulin (IRI), and glucagon (IRG) release from rat islets incubated in vitro was studied. Dopamine significantly suppressed the release of IRS (P< 0.001) and IRI (P < 0.001) and augmented IRG release (P < 0.001). Maximum suppression of IRS and IRI release was evident at 20 μm dopamine with half-maximal suppression occurring at 0.5–1 μm. Maximal stimulation of IRG release was observed at 100 μm dopamine with a halfmaximal response occurring at 5–10 μm. Suppression of IRS secretion by dopamine (20 μm) was completely reversed by the dopaminergic antagonists haloperidol (5 μm) and pimozide (5 μm), but was only partially reversed by the alpha adrenergic antagonist phentolamine (2 μm), and was further suppressed by the beta adrenergic antagonist propranolol (2 μm). Suppression of IRI release by dopamine was completely reversed by propranolol, but was unaffected by haloperidol, pimozide, and phentolamine. There results indicate that dopamine directly affects pancreatic islet D cell function, and that islet B and D cells appear to be more sensitive to dopamine than are A cells. Dopamine suppresses IRS secretion predominantly through activation of dopaminergic receptors, whereas it suppresses IRI release through an alpha adrenergic mechanism and stimulates IRG release through a beta adrenergic mechanism.
Relationships between fat and plasma androstenone and plasma testosterone in fatty and lean young boars during growth and after hCG stimulation
Authors: Bonneau M. , Meusy-Dessolle N. , Léglise P. C. , Claus R.
Published: December 2008

The effect of weight of fatty tissue on fat and plasma androstenone and on plasma testosterone relationships in the young boar was studied. For this purpose, hCG stimulation of steroid testicular production was performed in 12 boars and fat androstenone concentration subsequently measured. In addition plasma androstenone and testosterone were determined in 8 of them, previously cannulated.

The results show that: 1) although plasma testosterone response to hCG stimulation was similar in all boars, fat and plasma androstenone responses were very variable between boars, 2) weight of fatty tissue appeared to have little influence, if any, on androstenone exchanges between plasma and fatty tissue and 3) plasma androstenone/testosterone ratio appeared to be less variable within boars than between boars.

The data show that there is probably some between-boars-variability in the respective rates of elimination of testosterone and androstenone.
The effect of glibenclamide on plasma insulin, plasma somatomedin bioactivity and skeletal growth in hypophysectomized rats
Authors: Heinze E. , Ranke M. , Manske E. , Vetter U. , Voigt K.-H.
Published: December 2008

Male rats, body weight 60–75 g, were hypophysectomized. Three days after operation the animals were divided into two groups. Group B received solvent solution and group C 1 mg/kg body weight per day of glibenclamide ip for the following 9 days. Group A consisted on non-operated normal rats. Twenty-four hours after the last injections and after a 12 h overnight fast the body weights of groups B and C were not different, the increase during the 10 days being 10% in both groups. Serum insulin (IRI) was significantly higher in group C than in group B (C: 8.0 ± 0.3 μU/ml, n = 14 vs B: 4.9 ± 1.0 μU/ml, n = 14; P < 0.01, mean ± sem) as was serum somatomedin bioactivity (SM)-porcine cartilage assay — (C: 1.06 ± 0.1 U/ml, n = 14 vs B:0.41 ± 0.01 U/ml, n = 14; P < 0.001). Skeletal growth was determined with the tibia test and by a radiograph of each rat. The width of the proximal epiphyseal growth plate of the tibia was significantly increased in group C compared to group B (C: 204 ± 4.8 μm, n = 12 vs 181 ± 6.5 μm, n = 13; P < 0.005). On the radiograph the area of the right femur was not different between the two groups of animals, while the height and the area of the first lumbar spine were significantly augmented in group C. The results show that glibenclamide stimulates IRI, SM and skeletal growth in hypophysectomized rats.

Compared to the glibenclamide treated hypophysectomized animals the normal rats of group A had doubled their body weights. IRI (59 ± 5 μU/ml, n = 4) and skeletal growth (tibia test: 454 ± 5.8 μm) were greatly increased. SM did not differ between group A (1.21 ± 0.35 U/ml and group C. T4 was much lower in group B (0.64 ± 0.09 μg/100 ml, n = 5) than in group A (4.1 ± 0.3 μg/100 ml, n = 6; P < 0.001).

It is concluded that a normal SM concentration is not necessarily associated with appropriate growth.
The effects of thyroxine and triiodothyronine on the thyrotrophin response to thyrotrophin-releasing hormone in normal and iopanoic acid-treated euthyroid rats
Authors: Boado Rubén , Ulloa Edgardo , Zaninovich Angel A.
Published: December 2008

The present work studied the TSH response to TRH in T4- and T3-treated normal rats and in rats with depressed intrapituitary conversion of T4 to T3. Euthyroid normal rats were injected iv with a single dose of 6 μG T4/100 g body weight, 1 μg T3/100 g or normal saline. Another group treated with iopanoic acid (IOP) received 1 or 10 μg T4/100 g, 0.21 or 2.5 μg T3/100 g, or saline as control. Twenty min later 1 μg TRH/100 g was injected iv. Blood samples were drawn at times 0, 20 min (immediately preceding the injection of TRH) and 30 min (10 min post-TRH) for measurement of plasma T4, T3 and TSH. Other groups of IOP-treated rats were injected iv with 150 μCi of [3',5'-125I]T4; the hypophyses were removed at 30 min and homogenized in PBS buffer, extracted and chromatographed in tertiary amyl alcohol:hexane:ammonia. The control group of rats had a 13-fold increase in plasma TSH 10 min after the TRH injection, while rats treated with 6 μg T4/100 g had a 7.6-fold increase (P < 0.01 vs control increment) and rats treated with 1 μg T3/100 g had no change in TSH response as compared to controls. In IOP-treated rats injected with 10 μg T4/100 g there was a smaller increase in the TSH response to TRH as compared to control (P < 0.01), and a similar smaller response was seen in rats treated with 2.5 μg T3/100 g (P < 0.01 vs control). IOP-treated animals given 1 μg T4 or 0.21 μg T3/100 g had no significant changes in TSH response to TRH. It seems probable that T4 possesses an intrinsic hormonal capacity to regulate the secretion of TSH before it monodeiodinates to T3.
Dissociation of growth and function in the rat thyroid during prolonged goitrogen administration
Authors: Wynford-Thomas D. , Stringer B. M. J. , Williams E. D.
Published: December 2008

This study was designed to investigate the changes in growth and function which occur in the rat thyroid during prolonged TSH stimulation.

Animals maintained on the goitrogen aminotriazole were sacrificed together with controls at frequent intervals over a period of 5 months. The levels of serum T3 and T4 and TSH were measured by radioimmunoassay. Functional activity was assessed by measurement of the thyroid/serum iodide ratio (T/S) and growth by measurement of thyroid weight, follicular cell number and follicular cell mitotic activity.

Serum T3 and T4 rapidly fell to undetectable levels within 2 weeks. The level of serum TSH rose to a stable 5-fold maximum after 4 weeks. The T/S ratio followed a closely similar pattern rising to a sustained 7-fold maximum. Thyroid weight and follicular cell number increased rapidly for the first few weeks but the growth rate declined progressively, falling almost to zero after 80 days. Mitotic activity rose dramatically to a 30-fold peak after 7 days but then declined almost to normal after 80 days, consistent with the observed change in cell number. The results thus demonstrate a clear dissociation between the functional and proliferative activity of the thyroid follicular cells during prolonged stimulation by a sustained elevation of serum TSH and point to the existence of specific growth regulating mechanisms which limit the mitotic response.
Responses of plasma catecholamine and plasma renin activity after glucagon stimulation in essential hypertension
Authors: Uda Masanobu , Sakamoto Noboru , Tsuchiya Masayuki , Ito Keiichi , Ikeda Masao , Matsukura Shigeru , Fujita Takuo
Published: December 2008

To investigate the roles of the sympatheticoadrenomedullary system and the renin-angiotensin system in the pathogenesis of essential hypertension, the levels of plasma catecholamine and plasma renin activity (PRA) after glucagon-stimulation were evaluated.

In 9 patients with essential hypertension whose levels of PRA were either normal or high (NHREH), iv bolus injection of 1 mg glucagon caused a rapid and significant increase in plasma epinephrine concentration from the basal values of 170 ± 25 pg/ml, mean ± sem to 314 ± 30 pg/ml (P < 0.05) at 5 min after the injection, reaching the mean peak values of 358 ± 87 pg/ml (P < 0.05). Plasma norepinephrine also rose from the basal values of 357 ± 50 pg/ml to the peak values of 1065 ± 231 pg/ml (P < 0.02) while increase in PRA was detected in 4 of 9 patients.

In 7 patients with low renin essential hypertension (LREH), plasma epinephrine failed to increase after glucagon stimulation whereas plasma norepinephrine increased significantly from the basal values of 391 ± 77 pg/ml, reaching 1212 ± 274 pg/ml at their peak values (P < 0.01). There was no discernible response of PRA to glucagon.

These results suggest that both epinephrine secretion from adrenal medulla and renin release from juxtaglomerular (JG) cells after glucagon injection are impaired in LREH in contrast to their significant responses observed in NHREH. It also indicates that glucagon load may be useful for the simultaneous assessment of the reserve of both renin secretion and sympatheticoadrenomedullary function in essential hypertension.
Conversion of progesterone by testicular tissue of cryptorchid rats
Authors: Ficher Miguel , Steinberger Emil
Published: December 2008

The capacity of adult rat testes rendered surgically cryptorchid to metabolize progesterone1 was investigated at several time intervals (7, 14, 28 and 42 days) after surgery. Testicular tissue was incubated with [3H]progesterone, the steroid metabolites were isolated and purified using paper and thin layer chromatography, and further identified by isotopic dilution and recrystallization to constant 3H/14C ratio or constant specific activity (dpm/μmol). A sharp decrease in the accumulation of testosterone, concomitant with a marked increase in accumulation of 17α-hydroxyprogesterone, was observed as early as 7 days after surgery. No further major changes were observed at 14 or 28 days after surgery. However, at 42 days, accumulation of testosterone was substantially increased, while that of 17α-hydroxyprogesterone decreased to trace levels. 20α-Dihydroprogesterone was detected at different time intervals after surgery. The data suggest that cryptorchidism inhibits the activity of 17–20 desmolase for the first 4 weeks after surgery. The activity of this enzyme is restored by the 42nd day and the metabolic pathway between progesterone and testosterone resembles that of an intact rat. The factors responsible for this spontaneous restoration of the biosynthetic pathway are under investigation.
Serum somatomedin activity assayed by the enhancement of proteoglycan sulphation using chick embryo chondrocytes in normal children at various ages and childen of short stature
Authors: Maesaka Hatae , Yokoya Susumu , Tachibana Katsuhiko , Suwa Seizo , Yamagata Tatsuya
Published: December 2008

It was possible to obtain a sufficient amount of homogeneous chondrocytes from 13-day old chick embryo-sterna in an 8-day suspension culture. Serum somatomedin (SM) activity was measured on the basis of the ability of serum to stimulate labelled sulphate uptake in these chondrocytes. Somatomedin A and multiplication stimulating activity (MSA) stimulated the sulphation in this assay. Serum SM activity in term cord sera and newborn sera was lower than that in normal adults. Serum SM activity in early infants increased rapidly and attained the levels of that in normal adults within 1 month following birth. Serum SM activity in infants (1 month—2 years) and pubertal children (10–16 years), when the annual height increment is greatest, was higher than that in normal adults.

Serum SM activity in children with constitutinal dwarfism aged 6–10 years and over 10 years was normal and lower, respectively, compared to that in age-matched controls.

Pituitary dwarfs had markedly low SM activity compared to age-matched controls. Diagnostic evaluation of serum SM activity in children requires comparison with age-matched controls. Assay for serum SM activity may provide a useful and simple procedure for differentiating the cause of growth disorders from growth hormone deficiency.
Successful pregnancy in an acromegalic patient during 2-Br-α-ergocryptine (CB-154) therapy
Authors: Miyakawa Isao , Taniyama Keiichi , Koike Hiroyuki , Mori Norimasa , Nagamine Motohisa , Kuribayashi Tadanobu , Araki Shukuro
Published: December 2008

Foeto-placental function and hormone levels in the maternal, foetal and amniotic compartments have been investigated in an acromegalic woman who was treated with 20 mg bromocriptine/day throughout gestation. Bromocriptine therapy during pregnancy had no effect on urinary oestriol excretion and plasma levels of unconjugated oestriol, progesterone, human placental lactogen, cystine aminopeptidase and heat-stable alkaline phosphatase. The maternal and foetal (cord) blood and amniotic fluid showed prolactin levels of 3.8, 6.5 and 1700 ng/ml, respectively, in the 39th week of pregnancy during bromocriptine therapy. Compared with data from normal pregnancies, these values demonstrated that bromocriptine or an active metabolite crossed the term placenta to suppress prolactin secretion from the foetal pituitary gland and that the prolactin level in amniotic fluid was scarcely affected by the drug. Maternal, foetal and amniotic fluid growth hormone levels were 27.0, 33.0 and 3.8 ng/ml, respectively, thus indicating that dopamine agonists suppress growth hormone only in acromegalic patients, and not in normal babies. Bromocriptine had no effect on thyroid-stimulating hormone concentrations in the maternal, foetal and amniotic compartments.
A characterisation of cyclic AMP release from monolayer cultures of normal human thyroid cells
Authors: Bidey Stephen P. , Marshall Nicholas J. , Ekins Roger P.
Published: December 2008

The thyrotrophin (TSH)-dependent and time-related release of cyclic AMP has been characterised in primary monolayer cultures of normal human thyroid cells. Accumulation of cyclic AMP within the incubation medium was detectable within 1 h of exposure of cultures to 5 mU TSH/ml, and increased throughout of subsequent 15 h incubation period, final levels attained being consistently in excess of the corresponding intracellular cyclic AMP levels. Accumulation of cyclic AMP in the incubation medium was dependent on TSH dose, for both short (1 h) and prolonged (16 h) incubations. Moreover, after incubation for 16 h, cyclic AMP levels in the incubation medium were significantly (P < 0.01) in excess of intracellular levels for each dose of TSH tested above 0.2 mU/ml. In the absence of TSH, accumulation of cyclic AMP in the incubation medium remained low, after both 1 h and 16 h incubation periods.

A consideration of these observations suggests that a bioassay based upon the cyclic AMP content of incubation medium samples should provide a more precise detection system for thyroid stimulators than those measuring the intracellular cyclic AMP response, and this has been demonstrated for a cell preparation in which the intracellular response to TSH was minimal.
Effect of long-term iodide refeeding on the synthesis and secretion of T3, T4 and TSH in severe iodine deficient rats
Authors: Rognoni J. B. , Lemarchand-Béraud T. , Berthier C. , Simon C.
Published: December 2008

For 6 months, male Wistar rats received an iodine deficient diet (LID), with propylthiouracil (PTU) for the last 2 months. At the end of this treatment (day 0), a daily iodide intake of 20 μg (group 20) and 50 μg (group 50) was supplied. Synthesis and secretion of T3, T4 and TSH as well as thyroid and serum PBI were studied during 140 days of iodine repletion.

For the first 4 days of iodide refeeding, thyroid PBI remained low (0.4 ± 0.2 μg 127I/gland) whilst T3 and T4 were undetectable during 2 days only. Thereafter, these parameters increased regularly, reaching control values on days 80, 16 and 90, respectively. During 2 weeks, the thyroid T3/T4 ratio was 6-fold higher and reached the control value on day 45. Plasma T3 and T4 levels were low, but measurable for the first 4 days (0.5 ± 0.1 and 9.9 ± 2.6 nm, respectively). T3 rapidly reached a normal level on day 8, inducing a high plasma T3/T4 ratio for 16 days. This ratio decreased abruptly when T4 secretion increased, attaining the control value on day 45. Therefore, the preferential T3 secretion occurring during the first 16 days is directly linked to the preferential T3 synthesis. Plasma TSH levels remained 10-fold higher than the control value for the first 8 days (490 ± 99 vs 39 ± 15 μU/ml), then decreased abruptly and reached normal level after 1 month. Pituitary TSH contents varied in an opposite manner to the plasma TSH concentrations.

In conclusion, the effect of iodide on thyroid function occurs sequentially, i.e. thyroid hormone synthesis precedes neosecretion (latency phase). In both processes, T3 appears preferentially. This phenomenon is linked to the low thyroglobulin (Tg) iodination rate. In addition, the re-establishment of a normal thyroid hormone secretion prevailing over the iodinated Tg store constitution represents an adaptative mechanism; this leads rapidly to a maximum supply of active hormone (T3) with iodine economy. Moreover, it takes 2–3 months for the complete thyroid function restoration. At the pituitary level, the normal plasma T3 concentration found during the latency phase of iodide refeeding is not sufficient by itself to inhibit TSH secretion. This parameter starts to decrease only when T4 has reached a critical level to generate adequate T3 from T4 deiodination. Inhibition of TSH synthesis is a less sensitive process since it occurs for more elevated T4 concentrations. Finally, the similar pattern of thyroid function's recovery in the two groups indicates that the 20 μg dose is a sufficient supply and that thyroid autoregulation occurs, thus avoiding a thyroid hyperfunction.
Contribution from local conversion of thyroxine to 3,5,3'-triiodothyronine to intracellular 3,5,3'-triiodothyronine in several organs in hypothyroid rats at isotope equilibrium
Authors: van Doom J. , Roelfsema F. , van der Heide D.
Published: December 2008

The intracellular conversion of T4 to T3 was investigated in various tissues of hypothyroid rats after continuous iv infusion of radiolabelled T3 and T4. Two groups of 4 thyroidectomized rats were infused with carrier-free 125I-labelled T4 as well as 131I-labelled T3 until isotope equilibrium was achieved. Plasma, various tissue homogenates (liver, kidney, pituitary, thigh muscle, cerebral cortex and cerebellum) and subcellular fractions (nuclei, mitochondria, microsomes, cytoplasm) from liver, kidney and the pituitary gland were extracted for thin layer chromatography.

The [125I]T3/[131I]T3 ratios were determined and the extra contribution of [125I]T3 derived from local conversion of [125I]T4 to the total [125I]T3 was calculated in percent.

In addition to the [125I]T3 derived from plasma, [125I]T3 derived from locally converted [125I]T4 was present in all tissues investigated. There was substantially more, although in varying quantities, in the cerebral cortex (79 ± 2%), the cerebellum (68 ± 4%) and the pituitary gland (53 ± 1%) than in the liver (10 ± 6%), the kidney (11 ± 5%) and thigh muscle (17 ± 6%); in the latter tissues most of the 125I-labelled T3 is derived directly from plasma.

These results indicate that in the brain of severe hypothyroid rats there is pronounced conversion of T4 to T3 and effective binding of the T3 produced whereas the T3 in the liver, kidney, and muscle is predominantly derived from plasma. At the intracellular level, within the investigated tissues, the locally formed T3 was distributed equally over the subcellular fractions.
Regulation of parathyroid hormone release in primary and secondary hyperparathyroidism studies in vivo and in vitro
Authors: Rudberg C. , Åkerström G. , Ljunghall S. , Grimelius L. , Johansson H. , Pertoft H. , Wide L.
Published: December 2008

The effects of calcium on parathyroid hormone (PTH) release were studied in vivo and in vitro in primary hyperparathyroidism (HPT) and in vitro in secondary HPT. In vivo the serum PTH was clearly reduced by intravenous calcium infusion in all the examined patients with primary HPT caused by adenoma. In vitro the release of PTH from dispersed parathyroid cells was likewise suppressed by raising the calcium concentrations in the incubation media, though in all cases a basal release of PTH still persisted even at high calcium concentrations. The degree of suppressibility in vitro varied, but in both primary HPT with adenoma and in secondary HPT it was inversely related to the patients' serum calcium values. These results suggest that the secretion of PTH in patients with primary and secondary HPT is not autonomous either in vivo or in vitro. Furthermore, the non-suppressible basal release of PTH indicates that a major cause for the increased secretion of PTH is the increased number of parenchymal cells. However, the degree of suppressibility of the individual cells rather than the absolute number of cells, seems to be of great importance for the individual serum calcium values in HPT.
Circadian rhythm of catecholamines, cortisol and prolactin is altered in patients with apallic syndrome in comparison with normal volunteers
Authors: Ratge Dieter , Knoll Ernst , Diener Ulrich , Hadjidimos Alexander , Wisser Hermann
Published: December 2008

Circadian rhythms of catecholamines, cortisol and prolactin were investigated in 4 healthy subjects and in 6 patients suffering from an apallic syndrome. The clinical picture of this syndrome is characterized by disturbed consciousness (coma vigile), suspension of the sleeping and waking rhythm, lack of emotional reactions and appearance of primitive motor patterns. With the exception of dopamine a pronounced circadian rhythm was found in the control group for all investigated parameters. Catecholamines and cortisol showed a good correlation in the temporal pattern of plasma concentrations and urinary excreted amounts. In all apallic patients the circadian rhythm of prolactin was abolished. Only in one patient a rhythm of catecholamines and in 2 patients a rhythm of cortisol was still detectable. The data may indicate that the episodic nature of hormone secretion was essentially unaffected by the apallic syndrome. These results are regarded as an indication that endogenous, centrally controlled processes participate in circadian rhythms.
Central role of angiotensin in the hyperosmolality- and hypovolaemia-induced vasopressin release in conscious rats
Authors: Yamaguchi K. , Sakaguchi T. , Kamoi K.
Published: December 2008

To evaluate a central role of angiotensin in vasopressin (ADH) release in response to hyperosmolality or hypovolaemia, we examined in conscious rats the effects of intraperitoneal (ip) injections of 2 ml/100 g body weight of hypertonic saline or polyethylene glycol (PEG; 250 mg/ml of 145 mM NaCl) on plasma ADH and angiotensin II (AII) levels and of intracerebroventricular (icv) administrations of Sar1-Ala8-AII (a competitive receptor blocker for AII) on the plasma ADH responses to the ip injections. Thirty min after ip injections of 900 mm NaCl, plasma ADH, osmolality and sodium increased with unchanged plasma AII and with reduced haematocrit. Two h after ip administrations of PEG, plasma ADH, AII and haematocrit were augmented with un-altered plasma osmolality and sodium. The responses of plasma ADH to ip injections of 900 mM NaCl and PEG were significantly inhibited (P < 0.05) by 1 μg of Sar1-Ala8-AII injected icv 5 min before blood samplings which had no appreciable effect on plasma osmolality, electrolytes and haematocrit. Based on these results, we concluded that angiotensin may participate in both the hyperosmolality- and hypovolaemia-induced ADH secretion by acting on the central nervous system.
Lack of influence of the antidopaminergic drug domperidone on basal and TRH-stimulated TSH-serum levels after oral administration
Authors: Wenzel K. W. , Döring J.
Published: December 2008

Since antidopaminergic drugs are known to elevate basal and TRH-stimulated TSH-serum levels and since this effect was also shown after iv administration of the novel dopamine antagonistic agent domperidone, it was investigated, whether this antiemetic drug could interfere after oral intake with the evaluation of thyroid function. Oral domperidone caused a marked TSH-enhancement of TRH-induced TSH increments in 6 out of 14 euthyroid subjects, with no statistical significance, however. The difference between oral and parenteral influence as well as inter-individual changes are probably due to the varying first pass effect of the drug after oral absorption.
Regulation of somatotrophic and lactogenic binding sites in mouse liver membranes
Authors: Sasaki Norio , Imai Yasuo , Tsushima Toshio , Matsuzaki Fukashi
Published: December 2008

Both somatotrophic and lactogenic binding sites increase markedly in pregnant mouse liver membranes. The regulatory mechanisms of these binding sites involved in pregnancy are studied. The study of the effects of various hormone administration to female mice reveals that oestradiol increases and testosterone decreases lactogenic binding sites, and that other hormones affect neither somatotrophic nor lactogenic binding sites. Hysterectomy, adrenalectomy or foetectomy of pregnant mice cause a remarkable reduction of somatotrophic binding sites to the level observed in non-pregnant or post-partum animals. In contrast, the lactogenic binding sites are not influenced by these treatments. Replacement with corticosterone after adrenalectomy does not prevent the decrease of somatotrophic binding sites. The contents of placental lactogen from both adrenalectomized and foetectomized pregnant mice are similar to those of the normal pregnant group. These observations indicate that the regulatory mechanisms modulating somatotrophic and lactogenic binding activities are quite different and that increased somatotrophic binding sites during pregnancy are supported by the factor(s) generated in the foeto-placental unit and maternal adrenal gland.
Oestrogens, gonadotrophins and SHBG during oral and cutaneous administration of oestradiol-17β to menopausal women
Authors: Fåhraeus Lars , Larsson-Cohn Ulf
Published: December 2008

Thirty-eight post-menopausal women were randomly allocated to 6 months of treatment with either 2–4 mg of micronized oestradiol-17β taken orally or 3 mg of oestradiol-17β applied cutaneously. The plasma concentrations of oestrone, oestradiol, LH, FSH and sex hormone binding globulin (SHBG) were determined twice before and after 2,4 and 6 months of treatment.

In both groups the clinical effects were satisfactory. During treatment the mean oestradiol levels showed similar increases in the two groups while the oestrone concentration was markedly raised only among those taking oestradiol orally. The mean LH and FSH concentrations were significantly lowered in both groups. SHBG was increased with both treatments although more marked in the group on oral medication. Doubling of the oral dose from 2 mg to 4 mg gave significant changes of the LH, FSH and oestrone concentrations.

Thus, in the given doses, the two routes of administration seemed to have similar effects on post-menopausal symptoms and on the plasma concentrations of gonadotrophins and oestradiol. However the plasma oestrone and SHBG levels became significantly higher during the oral than during the cutaneous treatment.
Comparison between the progestin secretion responsiveness to gonadotrophins of rat cumulus and mural granulosa cells in vitro
Authors: Magnusson C. , Billig H. , Eneroth P. , Roos P. , Hillensjö T.
Published: December 2008

Several studies have shown differences in gonadotrophin receptor content between different granulosa cell (gc) populations within the ovarian follicle, but little is known about the gonadotrophin sensitivity in gc from different parts of the follicle. This study is an investigation of progestin synthesis and responsiveness to highly purified human and partly purified rat gonadotrophins. It involves short-term culture of rat cumulus and mural gc obtained from preovulatory follicles of PMSG-treated immature rats. The responsiveness to FSH in terms of progestin accumulation was similar in the two gc populations, whereas the responsiveness to LH was greater in the mural gc than in the cumulus. The morphological response in the cumulus cells (mucification) correlated with the steroidogenic response. The pattern of progestin synthesis differed between the two gc populations. In the cumulus gc progesterone was dominant, whereas 20α-dihydroprogesterone was the main progestin secreted in the mural gc. The difference in responsiveness to gonadotrophins correlates well with the reported differences in receptor content in the two gc populations.
Radioimmunological determination of somatomedin B in healthy children and in children with growth disturbances
Authors: Wirth S. , Schönberger W. , Roth A. , Grimm W.
Published: December 2008

Serum somatomedin B levels were determined by radioimmunoassay in 209 healthy boys and girls from one month to 16 years of age.

Low values were found up to the second year life. In the first year the mean level was 13.8 mg/l in girls and 11.5 mg/l in boys. In older children the values increased to levels between 13 and 22 mg/l in boys and between 13 and 18.5 mg/l in girls. They were independent of the stage of pubertal development.

Somatomedin B levels were normal in 71 children with constitutional growth delay, primordial dwarfism, familial dwarfism and other forms of growth disturbance. The mean levels were between 12.1 and 14.4 mg/l.

Values below 6 mg/l were present only in children with hGH deficiency. In these patients we could find an increase of the mean level from 4.3 mg/l without therapy to 9.4 mg/l under treatment.

Thus the determination of somatomedin B seems to be useful for the diagnosis of hGH deficiency.
Natural course of intermittent chronic autoimmune thyroiditis
Authors: Riddervold Fridtjov
Published: December 2008

A case with at least four spontaneous remissions from chronic lymphocytic autoimmune thyroiditis is presented.
Properdin factor B (Bf) and glyoxalase in Graves' disease
Authors: Allannic H. , Fauchet R. , Lorcy Y. , Phengsavath H. , Gueguen M. , Knoi T. D. , Genetet B. , Le Gall J. Y.
Published: December 2008

Patients with Graves' disease were phenotyped for properdin factor B (Bf) and glyoxalase, which are coded for by genes mapping close to the HLA region on the sixth chromosome. Frequency data were analysed in relation to HLA-A, -B and -DR typing data. Diagnosis of Graves' disease was based on the usual criteria including elevated T3 and T4 levels and free T4 index and a homogenous thyroid scan. Ninety-four patients with Graves' disease were phenotyped for properdin factor B (Bf) and 37 for red cells glyoxalase (GLO). HLA-A, -B and -DR antigens were typed in 94 patients using a lymphocyte microcytotoxicity assay. The frequency distribution of Bf and GLO alleles showed no significant differences from control subjects. This finding contrasts with the reports of an increased frequency of Bf Fl in insulin-dependent diabetes mellitus. The difference in the two diseases which are both associated with an increased frequency of the antigen combination D8-DR3, is accounted for by linkage disequilibrium between B 18 and BfF1.
Inhibitory effect of cyproheptadine on ACTH secretion in patients with Addison's disease
Authors: Loli P. , Frascatani F. , Gelli D. , Maggioni M. , Muratori F. , Ronzoni M.
Published: December 2008

In 14 patients with Addison's disease plasma levels of ACTH were studied after administration of a single oral dose (16 mg) of cyproheptadine.

The drug administration was followed by an inhibition of ACTH release.

These results support the view that cyproheptadine may exert an inhibitory effect on ACTH secretion in subjects whose corticosteroid feedback mechanism is normal.

We hypothesize that the effect of cyproheptadine might be related to its anti-serotonin or anti-histaminergic action.
Changes in the responsiveness of adrenal cells from foetal goats at different times during pregnancy
Authors: Challis John R. G. , Currie W. Bruce
Published: December 2008

To understand the factors responsible for the increased pre-partum output of cortisol from the adrenal glands of the goat foetus, we measured changes in responsiveness to ACTH in vitro of dispersed adrenal cells from foetal goats of various gestational ages and we determined the output of cortisol (F) and corticosterone (B) in the presence of exogenous progesterone (P4) and 17α-hydroxyprogesterone (17α-OHP4). The increment in F output after ACTH increased 5-fold between day 100 and days 147 or 154 (term). This increase was not associated with changes in the ED50 for ACTH stimulation of F output. The basal and ACTH-stimulated output of F was similar to that of B at day 100 but 5–7 times greater than that of B at day 154. There was a significant effect of ACTH on P4 output on days 77, 100 and 147 but net utilization of P4 by the cells at term. The ratio of exogenous P4: 17α-OHP4 converted to F varied with gestation and increased from 0.11 at day 100 to 0.99 at day 154. Exogenous P4 was converted to B at all stages of pregnancy.

We conclude that in the goat there is an increase in the responsiveness of foetal adrenal cells to ACTH between day 100 of gestation and term. One factor associated with this change in adrenal responsiveness may be an increase in the activity of the enzyme 17α-hydroxylase.
Regulation of inhibin secretion by Sertoli cell-enriched cultures
Authors: Verhoeven G. , Franchimont P.
Published: December 2008

Sertoli cells secrete a factor which has the same bioactivity as ovine testicular lymph inhibin: it selectively suppresses the secretion of FSH by cultured pituitary cells. We investigated the factors that acutely modulate the secretion of this inhibin by cultured Sertoli cells derived from immature rats. The secretion of inhibin was studied on day 7 of culture after a 24 h period of incubation in the presence or absence of steroids, gonadotrophins and foetal bovine serum, added alone or in various combinations. It could be demonstrated that aromatisable as well as non-aromatisable natural and synthetic androgens promote the secretion of inhibin in a dose-dependent way. FSH and pregnant mare serum gonadotrophin — at concentrations that clearly stimulate Sertoli cell aromatase activity — did not affect basal or androgen-stimulated production of inhibin. hCG was equally uneffective. The effect of androgens was not modified by the addition of an aromatase inhibitor but it was neutralized by the antiandrogen cyproterone acetate. Oestradiol-17β did not influence the secretion of inhibin whereas progesterone decreased it.

Serum enhanced basal as well as androgen stimulated secretion of inhibin. It is concluded that androgens are the major factor which acutely stimulates the production of Sertoli cell inhibin.
Endocrine expressions of hydrocephalus
Authors: Caporal R. , Segrestaa J. M. , Dorf G.
Published: December 2008

A Caucasian female, aged 28 years, presenting with obesity and investigated for primary amenorrhoea, was found to have hydrocephalus due to a stenosis of the foramen of Magendie.

Endocrine investigations showed an isolated gonadotrophin deficiency. Complete recovery was obtained by a ventricular-cardiac shunt, which led to the return of menses, a normal pregnancy, and then a return to normal weight.