bluuebunny/crossref_metadata_2025 huggingface dataset:
ADRENOCORTICOTROPHIN AND CORTICOSTEROID CHANGES DURING DEXAMETHASONE INFUSION TO INTACT AND SYNACTHEN INFUSION TO HYPOPHYSECTOMIZED FOETUSES
Authors: Jones C. T. , Kendall J. Z. , Ritchie J. W. K. , Robinson J. S. , Thorburn G. D.
Published: December 2008

Synacthen has been infused at 10 μg/h into 4 hypophysectomized foetal sheep. This caused a rise in adrenocorticotrophin to a mean value of 512 pg/ml which remained fairly constant and did not show the large fluctuations seen on infusion into intact foetuses. The Synacthen half-life in the circulation had a mean value of 0.27 min. Hypophysectomy did not necessarily delay the foetal corticosteroid response to Synacthen infusion. The corticosteroid concentration achieved had a mean value of about 50 ng/ml which is substantially below that for intact foetuses and in one case it was maintained at only 20 ng/ml. Despite this delivery occurred within 5 days. Dexamethasone infusion reduced the plasma adrenocorticotrophin concentration by about 70 % and the plasma cortisol concentration by about 60 %.
ENDOCRINE STUDIES IN A PUBERTAL MALE PSEUDOHERMAPHRODITE WITH 17-KETOSTEROID REDUCTASE DEFICIENCY
Authors: Virdis Raffaele , Saenger Paul , Senior Boris , New Maria I.
Published: December 2008

A 12 year old child (46,XY) with 17-ketosteroid reductase deficiency was investigated. The patient, reared as a female, was first noted to have clitoromegaly at 10 years of age. Increased facial hair, deepening of the voice, acne, increased body hair and minimal breast development were noted at 12 years. Δ-Androstenedione (Δ4) in peripheral blood was markedly elevated (1913 ng/100 ml) whereas testosterone (T) was in the male range of Tanner III puberty (240 ng/100 ml). Thus, Δ4/T in this patient was 9.4, compared to a normal ratio of 0.15 to 0.25. T/DHT was normal (10.5). Oestrone (Oe1) level was slightly elevated (6 ng/100 ml, normal: 2.5–4.5 ng/100 ml). Oestradiol (Oe2) was normal (1.7 ng/100 ml, normal: 1.5–3 ng/100 ml. Oe1/Oe2 was slightly elevated (3.6, normal: 1–2). At laparotomy, testes were found and spermatic vein blood was obtained prior to castration. Androgen determinations of spermatic vein blood demonstrated extremely high Δ4 levels (283 μg/100 ml) and low levels of T (16 μg/100 ml). Δ4/T in spermatic vein was 17, higher than in the peripheral blood, suggesting intact peripheral conversion of Δ4 to T. Incubation of testes slices with Δ4 demonstrated severely impaired conversion to T. Conversion of Oe1 to Oe2 was impaired to a lesser degree.

Conclusion:

17-ketosteroid reductase deficiency was documented in vivo by impaired conversion of precursor hormones resulting in higher than normal Δ4/T and Oe1/Oe2 ratios in blood. In vitro studies with testes slices confirmed the enzymatic defect.
DETERMINATION OF LUTEINIZING HORMONE IN BOVINE BLOOD BY RADIOLIGAND RECEPTOR ASSAY AND COMPARISON WITH RADIOIMMUNOLOGICAL EVALUATION
Authors: Schams D. , Menzer C.
Published: December 2008

A sensitive and specific radioligand receptor assay (RRA) using rat testis homogenate as the receptor source is described for measurement of luteinizing hormone (LH) in bovine blood. Interfering and non-specific substances in blood were removed by means of ion-exchange chromatography on CM-Sephadex C-50. Criteria of validation such as recovery of added LH to plasma or serum, reproducibility, and specificity gave good results. Inhibition curves obtained with bovine plasma and serum were parallel to those obtained with the bovine standard preparation. The range of the dose-response curve was between 0.5–20 ng of bovine LH. The pattern of LH concentrations in purified serum samples under different physiological conditions such as during the oestrous cycle and after administration of GnRH showed a very close correlation whether measured by means of radioimmunoassay (RIA) or receptor assay. Values of RRA-LH were consistently higher than those of RIALH. Thus the lower the RIA-LH levels, the more pronounced were the discrepancies between results of both assay systems. The mean ratio of RRA-LH/RIA-LH for basal levels (less than 1 ng RIA-LH/ml plasma) was 17.8 as compared to a mean ratio for higher peak values (more than 20 ng RIA-LH/ml plasma) of only 1.2.
A COMPARATIVE STUDY ON BIOASSAY AND RADIOIMMUNOASSAY OF VASOPRESSIN IN HUMAN URINE
Authors: Christensen Jens Dencker , Jensen Svend Erik
Published: December 2008

The excretion of vasopressin in urine from healthy human subjects under different stages of hydration was estimated in urine extracts by bioassay (rat antidiuresis) and radioimmunoassay. In normally hydrated subjects the excretion was 490 ± 164 μU/h and 430 ± 133 μU/h for bioassay and radioimmunoassay respectively (mean ± sem, n = 5). After total fluid restriction for 10 to 12 h the excretion increased to 1370 ± 329 μU/h for bioassay and 1163 ± 279 μU/h for radioimmunoassay (mean ± sem, n = 6). An oral water load (25 ml/kg) reduced the value to 169 μU/h (bioassay) and 118 μU/h (radioimmunoassay) (mean, n = 2). In general the biological estimations were 20 % higher than the immunological estimations (P < 0.01).

The urinary vasopressin excretion was positively correlated to urine osmolality. Synthetic arginine vasopressin (AVP) and urine extracts were both heterogeneous in ion exchange chromatography. The immunoreactive material was always eluted in 2 peaks, situated at the same places in the elution diagram. The material in the second peak was biologically active. The first peak from the AVP standard was biologically inactive, whereas the same peak from urine extract was active. This peak was shown to be an artefact formed during the extraction procedure.
THE EFFECT OF CYPROTERONE ACETATE ON THE PITUITARY-ADRENAL AXIS IN HIRSUTE WOMEN
Authors: Smals A. G. H. , Kloppenborg P. W. C. , Goverde H. J. M. , Benraad Th. J.
Published: December 2008

The functioning of the hypothalamo-pituitary-adrenal axis was assessed in 10 adult women with idiopathic hirsutism treated for 2 weeks with the anti-androgen cyproterone acetate in a dose of 50 mg b. d. daily and in 4 patients treated for at least 3 months.

Basal plasma ACTH and cortisol levels and the cortisol response to 8 h ACTH infusion were comparable before and during short-term treatment. The plasma ACTH and cortisol responses to insulin induced hypoglycaemia before and during anti-androgen therapy also were of the same order of magnitude. In the 4 patients treated for at least 3 months also no suppressive effect of the anti-androgen on basal plasma cortisol levels was observed.

From these data the conclusion seems warranted that short-term cyproterone acetate treatment in the given dose not significantly influences pituitary-adrenal function in adult women with idiopathic hirsutism.
THE EFFECTS OF ARGININE VASOTOCIN ON PREGNANT MARE'S SERUM-INDUCED OVULATION IN THE IMMATURE FEMALE RAT
Authors: Johnson Linda Y. , Vaughan Mary K. , Reiter Russel J. , Blask David E. , Rudeen P. Kevin
Published: December 2008

Arginine vasotocin (AVT) treatment (1 μg/injection) every two hours beginning at 06.00 h on the morning preceding expected ovulation significantly inhibited ovulation in 29-day-old immature female rats treated 2 days earlier with 30 IU of PMS. Pre-ovulatory plasma surges and pituitary decreases in LH, FSH and prolactin as measured by radioimmunoassay were not eliminated by AVT treatment. However, there appeared to be an early rise in plasma FSH in these rats and the maximum plasma LH value attained during the surge period in PMS-treated rats was elevated by AVT treatment. Arginine vasotocin significantly inhibited the increase in ovarian weight which occurs in PMS-treated rats on the day preceding ovulation and uterine weights were consistently depressed in AVT-treated rats. The results of this study indicate that AVT likely inhibits PMS-induced ovulation at the level of the ovary, although the possibility cannot be ruled out that inhibition resulted from the advancement of the plasma FSH rise. These data and other studies investigating the effects of AVT on reproduction indicate that AVT is possibly capable of acting at more than one level of the hypothalamo-hypophyseal-gonadal axis.
SUGGESTION OF ABNORMAL TESTICULAR STEROIDOGENESIS IN SOME OLIGOSPERMIC MEN
Authors: Rodriguez-Rigau Luis J. , Weiss David B. , Smith Keith D. , Steinberger Emil
Published: December 2008

Androgen biosynthesis in the testis may be analyzed in some detail by means of techniques of in vitro incubation of small testicular biopsy specimens with suitable radiolabelled precursors. Sixty-six tissue specimens from 33 patients who underwent bilateral testicular biopsies because of infertility were incubated in vitro with [3H]pregnenolone in order to investigate the possibility of abnormalities in their steroid biosynthetic activity. As a normal control, testicular tissue obtained by testicular biopsy from a young normal volunteer was used. The distribution of metabolites in the incubates of testes from 8 infertile men differed greatly from the remaining 25 patients and the normal control. The major steroids formed from pregnenolone by the testes of those 8 men were 17-hydroxypregnenolone, dehydroepiandrosterone, 20α-dihydropregnenolone and 20α-dihydro-17-hydroxypregnenolone. Very small amounts of Δ4-3 oxo products (progesterone, 17-hydroxyprogesterone, androstenedione and testosterone) were formed suggesting a deficiency of 3β-hydroxy-steroid-dehydrogenase activity in the testes of these 8 men, possibly related to the derangement of their spermatogenic function.
ANNUAL AND DIURNAL CHANGES IN PLASMA ANDROGEN AND CORTISOL IN ADULT MALE SQUIRREL MONKEYS (Saimiri sciureus) STUDIED LONGITUDINALLY
Authors: Wilson Margo I. , Brown Gregory M. , Wilson David
Published: December 2008

Plasma androgen (testosterone + dihydrotestosterone) and cortisol levels of fully mature wild-reared male squirrel monkeys were measured using radioimmunoassay and protein binding methods, respectively. A total of 337 plasma samples were collected over a 24-h period, and at weekly and bi-weekly intervals for a period of 13 months. Plasma levels of androgen (mean ± se = 58.1 ± 4.0 ng/ml) and of cortisol (112.8 ± 4.8 μg/100 ml) are markedly higher in squirrel monkeys than in Old World monkeys. There were significant individual differences in plasma androgen levels. There was no apparent diurnal or annual cycle in plasma androgen levels. A group of 4 male squirrel monkeys housed in isolation cubicles had much higher levels of plasma cortisol (170.1 ± 7.7 μg/100 ml) than 10 non-isolated males (92.7 ± 4.3 μg/100 ml). There was a diurnal cycle in plasma cortisol for animals maintained in isolation cages, but non-isolates did not exhibit a diurnal pattern in plasma cortisol. There was no statistically significant correlation between plasma androgen and plasma cortisol levels; high levels of cortisol were not necessarily associated with low androgen levels. The variations in plasma androgen could not be attributed to any reliable cyclic phenomena, nor to stress, but may be due to maintaining animals under laboratory conditions.
ISOLATION AND CHARACTERIZATION OF INHIBIN FROM BULL SEMINAL PLASMA
Authors: Chari S. , Duraiswami S. , Franchimont P.
Published: December 2008

A simple, short procedure for the isolation of inhibin from bull seminal plasma has been described. Following conversion of the seminal plasma into acetone powder, it was subjected to gel filtration on Sephadex G-100 using 4 m urea—0.05 m sodium acetate buffer pH 4.0 as the eluent. Further purification of the active fraction was achieved by 'straight elution analysis' using CM-cellulose.

The final preparation (Ux) has been shown to reduce the response of immature rat ovaries to human chorionic gonadotrophic hormone (HCG) stimulation in the bioassay system of Chari et al. (1976) and also been shown to suppress the immediate post-castration rise in serum gonadotrophin levels in immature male rats.

Homogeneity of the isolated fraction has been assessed electrophoretically at different pH's above and below its isoelectric point. On the basis of gel filtration studies, electrophoresis and amino acid analysis, the molecular weight of Ux has been estimated to be 19 000 daltons. The electrophoretic behaviour of Ux at an alkaline pH has been discussed as a possible evidence for its existence as isohormones.
ATP-INDUCED RELEASE OF VASOPRESSIN ASSOCIATED WITH PHOSPHORYLATION OF ISOLATED BOVINE NEUROHYPOPHYSEAL SECRETORY GRANULE MEMBRANES
Authors: Russell James T. , Thorn Niels A.
Published: December 2008

Secretory granules isolated from ox neurohypophyses released their content of vasopressin in the presence of ATP and Mg2+. A half maximal ATP concentration of 0.25 mm was found. Ca2+ was not necessary for the effect. High concentrations of ADP, AMP and ITP were shown to mimic the effect of ATP.

Utilizing this effect of ATP combined with iodonitrotetrazolium treatment to make mitochondria heavier, a method is described to obtain granule "ghosts" in a purified form. They were shown to be phosphorylated when granules were incubated with [γ-32P] ATP.
HIGH-AFFINITY BINDING OF REVERSE T3 AND TETRAC IN NUCLEI OF HUMAN LYMPHOCYTES
Authors: Lemarchand-Béraud T. , Holm A.-C. , Bornand G. , Burger A.
Published: December 2008

In a previous study, human lymphocyte nuclei were found to possess high affinity, low capacity binding sites for triiodothyronine (T3) and thyroxine (T4). The number of receptors per cell was similar for T3 and T4 (115±20), but the equilibrium affinity constant (Ka) for T3 (2.20±0.23 1010m−1) was twice that for T4 (1.05 ± 0.25 1010m−1). The present study shows that human lymphocyte nuclei also bind highly purified [125I]tetrac and [125I]rT3. The number of specific binding sites was 60 for tetrac and 40 for rT3. The Ka for tetrac (2.12 ± 0.29 1010m−1) was similar to that of T3, whereas that of rT3 (1.31 ± 0.2110m−1) was similar to that of T4. The Ka was the same when measured in intact cells and in nuclei isolated after incubation. Despite the similar Ka for tetrac, rT3 and T3, as obtained by direct measurements, tetrac had only 2 % and rT3 0.1 % of the T3 potency in T3 displacement studies. [125I] tetrac was displaced 50% by 20 fmol of T3 and [125I]rT3 by 8 fmol.

These results show that tetrac and rT3 do bind as strongly to nuclear receptors as T3 and T4, but that when competing with T3 the apparent affinities decrease considerably for tetrac and rT3. Thus, the nuclear binding of these two analogues probably has no significance under physiological conditions, but may play some role under pathological conditions when the formation of T3 is decreased and that of rT3 and tetrac is increased. This may represent an adaptive mechanism in T4 inactivation.
INSULIN RELEASE, INSULIN CONTENT, AND GLUCOSE UTILIZATION IN ISOLATED MOUSE ISLETS MAINTAINED IN TISSUE CULTURE
Authors: Eff Christian
Published: December 2008

To elucidate the remission phase in juvenile diabetics the insulin release, insulin content, and glucose utilization were measured in isolated Langerhans' islets from mice maintained for 6 days in a tissue culture at a glucose concentration of 278 mmol, followed by a culture period of 4 days at 6.1 mmol glucose.

These experiments revealed that the ability of the islets to store and secrete insulin during glucose stimulation decreased considerably during incubation at high concentrations of glucose. When the glucose concentration in the incubation medium was reduced, these properties could be re-established. Basal as well as glucose-stimulated glucose utilization increased greatly during incubation at high glucose concentrations. However, it was not possible to normalize the glucose utilization during 4 days' incubation at 6.1 mmol glucose. The results indicate that unphysiologically high concentrations of glucose may induce long-lasting changes in the function of Langerhans' islets.
UNUSUAL HETEROZYGOTES OF CONGENITAL ADRENAL HYPERPLASIA DUE TO 21-HYDROXYLASE DEFICIENCY
Authors: Zachmann M. , Prader A.
Published: December 2008

Three otherwise healthy relatives of patients with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency and salt-wasting presented with clinical and/or biochemical findings, which exceeded those usually seen in heterozygotes: Two females (1 mother and 1 prepubertal sister of a patient with CAH) had marked hypertrichosis and hirsutism and excreted pregnanetriolone in their urine. The mother had increased basal plasma 17α-OH-progesterone (296 ng/100 ml), which increased to 7170 ng/100 ml after ACTH as in homozygotes of CAH. One adult male (brother of a patient with CAH) was clinically normal, but also excreted pregnanetriolone and had a high plasma 17α-OH-progesterone (1905 ng/100 ml), which increased further to 6352 ng/100 ml after ACTH. It is concluded that these subjects represent unusually marked heterozygotes of CAH rather than mild homozygotes. In females, this condition should be included in the differential diagnosis of idiopathic hirsutism, in males, it will pass unnoticed, unless relatives of patients with CAH are systematically tested.
PLASMA PREGNENOLONE AND 17-OH-PREGNENOLONE IN HIRSUTE AMENORRHOEIC PATIENTS
Authors: Lorber D. L. , McKenna T. J. , Rabinowitz D.
Published: December 2008

This study was designed (a) to examine the involvement of the Δ5-pregnenes, pregnenolone and 17-OH-pregnenolone in the abnormal steroidogenesis present in hirsute patients; and (b) to examine the possibility that suppressed adrenal 21-hydroxylase activity may frequently underlie the abnormal steroidogenesis in hirsute women. Basal plasma pregnenolone and 17-OH-pregnenolone levels were significantly elevated in hirsute women. The levels of these steroids following treatment with dexamethasone and the decrement induced by this treatment were also significantly greater in hirsute patients than in normal subjects. These precursor steroids were also excessively responsive to stimulation with HCG in the hirsute patients.

Urinary 17-hydroxycorticosteroid excretion was significantly higher in hirsute patients than in normal subjects. In contrast, the urinary excretion of pregnanetriol, either under basal conditions or following stimulation with ACTH was not significantly higher than in normal women similarly treated. In a further attempt to identify any limitation in 21-hydroxylase activity, the steroidogenic response to ACTH plus metyrapone was measured in hirsute and in normal women. Neither the urinary pregnanetriol response nor the ratio of pregnanetriol to 17-hydroxycorticosteroids was elevated in hirsute women.

These observations document that plasma pregnenolone, and 17-hydroxypregnenolone are elevated in hirsute patients. The excess appears to be derived both from the adrenals and the ovaries. However, we were unable to demonstrate any limitation in adrenal 21-hydroxylase activity in hirsute patients.
SUPRASELLAR EXTENSION OF TUMOUR ASSOCIATED WITH INCREASED CEREBROSPINAL FLUID ACTIVITY OF LH AND FSH
Authors: Luboshitzky R. , Barzilai D.
Published: December 2008

A 65 year old man with pituitary adenoma, partial hypopituitarism and normal serum FSH and LH concentration is described. LH (but not FSH) partially increased following the administration of LH-RH. Subsequent FSH and LH assays of the cerebrospinal fluid, however, showed a high and correctly predicted suprasellar extension of the tumour.
EVIDENCE FOR A DIFFERENT RESPONSE OF RED AND WHITE SKELETAL MUSCLE OF THE RAT IN DIFFERENT THYROID STATES
Authors: Janssen J. W. , van Hardeveld C. , Kassenaar A. A. H.
Published: December 2008

The influence of thyroid hormone depletion and experimental hyperthyroidism on red and white skeletal muscle of the rat during periods of 2, 4 and 8 weeks were studied. Body weight, muscle weight, mitochondrial protein content, and specific activities of the mitochondrial enzymes α-glycerophosphate dehydrogenase (EC 1.1.99.5) (α-GPD) and succinate dehydrogenase (EC 1.3.99.1) (SDH) were used as parameters. The largest differences in body weight gain and muscle weight gain (both red and white muscle) in the hypothyroid rats were seen after 8 weeks of T4 treatment. In the hyperthyroid rats the weight of the red muscle and the ratio of the red muscle weight to the body weight increased, whereas the white muscle weight and the ratio of the white muscle weight to the body weight decreased relative to the control animals.

In hypothyroid rats the mitochondrial protein content was lowered in both red and white muscle, the specific α-GPD activity only in the latter. No changes in specific SDH activity were observed in either type of muscle. The hyperthyroid rats showed an increase in the mitochondrial protein content and the specific α-GPD and SDH activity in the red muscle, whereas no significant changes were observed in the white muscle. The changes in the parameters under study show that the effect of the thyroid state differs in red and white muscle. An explanation for a possibly greater sensitivity of red than of white muscle to thyroid hormones is discussed.
ROLE OF NEUROTRANSMITTERS, PROSTAGLANDINS AND GLUCOSE ON PRECURSOR INCORPORATION INTO THE RNA OF THYROID SLICES
Authors: Juvenal Guillermo J. , de Pisarev Diana L. Kleiman , Crenovich Liliana , Pisarev Mario A.
Published: December 2008

The present studies were performed in order to investigate the role of neurotransmitters, prostaglandins and glucose on [3H]uridine incorporation into total RNA in beef thyroid slices. Carbamylcholine strongly stimulated RNA labelling from [3H]uridine; atropine abolished this effect. NaF, at 1 and 5 mm, progressively increased this parameter while norepinephrine caused a similar effect at 10−3 but not at 10−6 M. Phentolamine (1 mm) blocked the stimulatory action of TSH; propranolol and atropine did not. Glucose at concentrations between 4 and 24 mm caused a progressive increase in RNA labelling from [3H]uridine. This effect was not inhibited by dinitrophenol. Prostaglandins (E1, A1, F1α and F2α) assayed in concentrations between 5 and 25 μg/ml, with or without caffeine, had no effect on RNA labelling. Moreover, neither aspirin nor indomethacin inhibited TSH stimulation. Under similar experimental conditions, PGE1 did simulate PB125I formation.
LACK OF CORRELATION BETWEEN ADRENAL cAMP AND CORTICOSTEROIDOGENESIS IN THE NEWBORN RAT
Authors: Cote Thomas E. , Yasumura Seiichi
Published: December 2008

In 2 to 16-day-old rats subjected to heat, the adrenal content of cAMP did not increase in animals younger than 14 days of age, but serum corticosterone was significantly higher than control values at all ages except in 10 and 12-day-old animals. This would suggest that cAMP may not mediate the adrenal steroidogenic response to stress during the first postnatal week. This hypothesis is consistent with the fact that the administration of 0.195 and 0.785 mU ACTH to 2-day-old rats resulted in a significant increase in serum corticosterone without a rise in the adrenal content of cAMP. The stress-induced rise in serum corticosterone progressively diminishes during the first post-natal week before returning to its previous 2-day-old capacity by day 16.
A RECEPTOR-IMMUNOASSAY FOR THE DETERMINATION OF THE SPECIFICITY OF ANTI-HCG-β SERA
Authors: Jibiki K. , Saxena B. B.
Published: December 2008

In the receptor-immunoassay, the binding of anti-HCG-β sera to 125I-HCG and 125I-HLH is measured in the presence of bovine corpus luteum 'receptor'. Anti-sera specific for HCG show little binding with 125I-HLH. The receptor-immunoassay permits an evaluation of specificity, affinity and the ability of anti-HCG-β sera to compete with the 'receptor' for binding to 125I-HCG.
HYPOTHALMIC-PITUITARY ADRENAL RESPONSIVENESS TO DEXAMETHASONE-INSULIN TOLERANCE TEST IN ACROMEGALIC PATIENTS BEFORE AND DURING TREATMENT WITH BROMOCRIPTINE
Authors: Harrower A. D. B. , Davidson N. McD. , Yap P. L. , Nairn I. M. , Fyffe J. A. , Horn D. B. , Strong J. A.
Published: December 2008

Insulin tolerance tests were carried out in 10 acromegalic patients after 1 mg dexamethasone had been given the previous evening (DEX-ITT). Nine patients showed a rise in plasma 11-OHCS and four patients showed a rise in plasma growth hormone (GH) levels. These responses were unaltered after treatment with bromocriptine 10 mg daily for two months. Basal plasma GH levels fell in 6 of the patients and the mean plasma GH levels of the 10 patients during an oral glucose tolerance test (OGTT) fell from 63.2 ± 25.5 ng/ml before treatment to 53.0 ± 27.1 ng/ml (mean ± sem; P < 0.05). These data fail to confirm a previous report of abnormal hypothalmic-pituitary-adrenal suppressibility during a DEX-ITT in acromegalic patients. They also indicate that bromocriptine does not alter the responses of plasma 11-OHCS and plasma GH to the DEX-ITT despite lowering plasma GH levels.
GONADOTROPHIN RESPONSE AFTER CASTRATION AND SELECTIVE DESTRUCTION OF THE TESTICULAR INTERSTITIUM IN THE NORMAL AND ASPERMATOGENIC RAT
Authors: Morris I. D. , Jackson C. M.
Published: December 2008

Serum LH and FSH were measured by radioimmunoassay in adult male rats previously rendered aspermatogenic by a high dose of α-chlorohydrin. In the aspermatogenic rat serum FSH was elevated but LH levels and androgen dependent organ weights were within normal limits. Transient destruction of the interstitium with a resultant decrease in testicular androgen secretion by ethylenedimethane sulphonate (EDS) in the normal rat preferentially increases serum LH. However, in the aspermatogenic rat EDS increased both serum LH and FSH to levels indistinguishable from those of the normal castrate. The pattern of gonadotrophin secretion in the EDS treated aspermatogenic rat suggested that the dynamic changes after the disturbance of the androgenic feedback were faster than those found in the normal male rat. Castration of the aspermatogenic rat produced serum gonadotrophin levels comparable to the 27 day normal castrate within I and 2 days for LH and FSH, respectively. The data supports the concept of the dual control of pituitary gonadotrophin secretions arising from the seminiferous tubule (inhibin) and the interstitium (androgen). In addition the results also suggest that inhibin acts to modify pituitary sensitivity to endogenous LH-RH as the removal of the androgenic feedback signal in the aspermatogenic rat either by EDS or castration results in a faster achievement of castrate gonadotrophin levels.
INSULIN TEST: PRECISIONS OF AND CORRELATIONS BETWEEN GLUCOSE AND HORMONE RESPONSES
Authors: Leisti Seppo , Perheentupa Jaakko
Published: December 2008

Insulin test was given twice to each of 41 reference subjects and 31 hypopituitary patients to establish the most precise parameters of glucose and hormone responses, and the intra-individual dependence of these responses on each other.

The precision was highest for the glucose response, intermediate for the cortisol and epinephrine responses and lowest for the GH response. The most precise parameters were: for blood glucose, recovery index, maximum per cent decrement, maximum absolute decrement and minimum level; for plasma cortisol, maximum level, post-insulin area and increment area; for plasma GH, maximum level and post-insulin area; and for epinephrine excretion, absolute post-insulin rate and absolute post-insulin increment. Unacceptably poor precision was established for some parameters in common use: the maximum and 60 min increments in cortisol and GH, and the per cent increment in epinephrine.

The intra-individual correlations suggest differences in the mode of stimulation of the different hormone secretions in response to acute hypoglycaemia. While the cortisol response correlated best with the absolute glucose decrement, the epinephrine response correlated best with the absolute minimum glucose level. Per cent glucose decrement showed no correlation with the hormone responses. GH response showed no correlation with any parameter of acute hypoglycaemia.

Prolonged hypoglyaemia leads to responses in cortisol, GH and epinephrine secretion. No intra-individual correlations were present between the responses of these hormones, but the basal cortisol level was correlated both with the basal rate and with the response in epinephrine excretion.

For maximum clinical information strict standardization of the test procedure is necessary, with use of the most precise parameters of the responses. For plasma cortisol and GH responses the preferable parameters are the maximum levels. The cortisol maximum should be corrected for its dependence on the basal level, so increasing its precision. For the epinephrine response the absolute post-insulin rate of excretion is convenient and precise.
HCS-HCG REGULATION IN CULTURED PLACENTA
Authors: Belleville F. , Lasbennes A. , Nabet P. , Paysant P.
Published: December 2008

Tissue culture has been used to study the action of different substrates on the secretion of HCG and HCS in human placental explants. The following compounds have been studied: prostaglandins E2 and F2α, adrenaline and noradrenaline, oestriol and progesterone, glucose concentration.

The investigators first measured the normal secretion of three term placentas and 2 months placentas. The activity of the compounds tested is expressed in per cent of the normal values. The investigators have checked that the cultivated cells were always viable by measuring the oxygen consumption during all the experiments.

PG E2 and F2α are without action on term placentas.

Adrenaline and noradrenaline reduce significantly the secretion of HCS by full term placentas and have no action on HCG secretion.

Oestriol always stimulates HCS secretion by full term placentas and 2 months old placentas, whereas progesterone stimulates young placentas and inhibits full term placentas. Both steroids have no action on HCG secretion.

Glucose is essential for HCS secretion by placentas but high values of glucose in the medium significantly reduce the HCS secretion by full term placentas.
PITUITARY-ADRENAL RESPONSE TO STIMULATION OF THE LIMBIC SYSTEM AND LATERAL HYPOTHALAMUS IN THE RHESUS MONKEY (MACACCA MULATTA)
Authors: Frankel R. J. , Jenkins J. S. , Wright J. J.
Published: December 2008

Various sites within the limbic system, frontal lobe and lateral hypothalamus of the rhesus monkey brain were electrically stimulated using chronically implanted electrodes. Increases in plasma cortisol was observed after stimulation of the lateral hypothalamic area, basolateral amygdala, pyriform cortex, hippocampus, certain sites in the cingulate gyrus and orbital part of the frontal lobe. Inactive sites included the caudate nucleus, putamen and white matter in the frontal lobe.
PROLACTIN AND TSH RESPONSES TO TRH, CHLORPROMAZINE AND L-DOPA IN CHILDREN WITH HUMAN GROWTH HORMONE DEFICIENCY
Authors: Okada Y. , Onishi T. , Tanaka K. , Morimoto S. , Tsuji M. , Watanabe K. , Okazaki A. , Takeuchi T. , Kumahara Y.
Published: December 2008

Prolactin (PRL) and TSH responses to TRH, chlorpromazine (CPZ) and L-DOPA were studied in 23 children (15 male and 8 female) with human growth hormone (HGH) deficiency. Eight patients (group I) showed normal PRL response to TRH and CPZ but TSH response to TRH was delayed in 4 of this group. Twelve patients (group II) had normal (4 patients) or higher (8 patients) baseline PRL level and showed lower PRL response to CPZ than that to TRH. TSH response to TRH was normal in 3, blunted in 1, and delayed in 8 patients. Three patients (group III) had no PRL response to either TRH or CPZ. TSH response to TRH was normal in 1 but blunted in 2 patients. Of 8 patients with a higher baseline PRL level (group II and III), L-DOPA suppressed PRL secretion to less than 50 % of the initial value in 7 patients, but not in 1 patient, in whom the diagnosis of hypothalamic tumour was established on brain surgery following these examinations. These results suggest that hypothalamic disorders are involved in more than half of 23 children with HGH deficiency.
TISSUE CULTURE STUDIES ON HUMAN PITUITARY TUMOURS: RADIOIMMUNOASSAYABLE ANTERIOR PITUITARY HORMONES IN THE CULTURE MEDIUM
Authors: Lipson Loren G. , Beitins Inese Z. , Kornblith Paul D. , Mc Arthur Janet W. , Friesen Henry G. , Kliman Bernard , Kjellberg Raymond N.
Published: December 2008

A tissue culture study was undertaken to determine if human non-functioning pituitary tumours secrete polypeptide anterior pituitary hormones in vitro and to study the spectrum of hormone release by functioning pituitary neoplasms. Fragments from 48 human pituitary tumours (from patients - 2 with Cushing's disease, 1 with Nelson's syndrome, 5 with amenorrhoea-galactorrhoea, 10 with acromegaly and 30 with non-functioning pituitary tumours) and three normal human anterior pituitary glands (controls) were placed in tissue culture immediately after surgery. The in vitro release of human growth hormone (HGH), prolactin (Prl), thyrotrophin (TSH), adrenocorticotrophin (ACTH), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassays at the end of one week in culture. Clinical and pathological data were compared to hormone release patterns.

In the culture media from control pituitaries the concentrations of the six hormones tested were 100 to 10 000 times greater than in peripheral blood. The medium surrounding the fragments from functioning pituitary tumours contained the following: a) Acromegaly - high levels of HGH and variable concentrations of the other hormones. b) Cushing's disease - ACTH and Prl predominantly. c) Amenorrhcea-galactorrhoea syndrome - prolactin in 4 out of 5 patients, all six polypeptides in one patient. In the media from the 30 patients diagnosed as having non-functioning pituitary tumours, 60 % of the samples contained at least one hormone at a concentration similar to that of the controls and 100 % of the samples contained detectable quantities of at least one hormone.
OBSERVATIONS ON SUCCESSIVE PRO-OESTROUS LH SURGES IN INDIVIDUAL 4-DAY CYCLING AND POST-PSEUDOPREGNANT RATS
Authors: Carrillo Alberto J. , Sawyer Charles H.
Published: December 2008

The internal variations (i. e. in timing, duration and amplitude) of the LH surge mechanism within individual rats were examined by monitoring from 3 to 7 successive pro-oestrous LH surges in each of 5 regular 4-day cycling rats fitted with chronic intravenous cannulas. On each successive pro-oestrus blood was collected (0.5–0.6 ml hourly from 14.00–21.00) for radioimmunoassay of LH. The surgery of cannulation had no long-term effect on the regularity of the oestrous cycle. Two rats did, however, show briefly irregular cycles, including one with a 9-day period of anoestrus (pseudopregnancy). In three of the five rats successive pro-oestrous plasma LH curves (4 in one and 3 each in the other two) were internally very consistent in timing, shape and amplitude, However, between each 2 of these 3 animals there were distinct differences in the LH secretory patterns, by as much as 2 h in timing of the onset of the surge and its peak amplitude. The first two surges of the other two rats were atypical of their subsequent surges, which were mostly consistent in timing and amplitude. The pro-oestrous LH surge following the 9-day period of anoestrus was advanced by 2 h and elevated to twice the mean peak amplitude of the cyclic LH surges in that rat. Subsequently, post-PSP surges were studied in rats made pseudopregnant by mechanical stimulation of the cervix. In all cases the immediate post-PSP surge occurred earlier in the afternoon and with a greater peak amplitude than the subsequent cyclic LH surge in the same rat.
THE RELATIVE DISTRIBUTION OF THYROXINE, TRIIODOTHYRONINE AND 3,3′,5′-(REVERSE)-TRIIODOTHYRONINE IN VARIOUS FRACTIONS OF THYROGLOBULIN
Authors: Laurberg Peter
Published: December 2008

Thyroglobulin fractions rich and poor in new thyroglobulin were separated by means of DEAE-cellulose chromatography of dog thyroid extracts and by zonal ultracentrifugation in a sucrose gradient of guinea pig thyroid extract incubated at low temperature. The distribution of thyroxine, triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine in hydrolysates of the different fractions was estimated by radioimmunoassays. Following DEAE-cellulose chromatography there was a small but statistically significant increase in the T4/T3 ratio in thyroglobulin fractions eluted at high ionic strength - that is fractions relatively rich in stable iodine but poor in fresh thyroglobulin. There were no differences in the T4/rT3 ratios between the different fractions. The ratios between iodothyronines were almost identical in the various thyroglobulin fractions following zonal ultracentrifugation in a sucrose gradient of cold treated guinea pig thyroid extract.

These findings lend no support to the possibility that a relatively high content of triiodothyronines in freshly synthesized thyroglobulin modulates the thyroid secretion towards a preferential secretion of triiodothyronine and 3,3′,5′-(reverse)-triiodothyronine at the expense of the secretion of thyroxine.
PARTIAL GONADOTROPHIN-RESISTANCE IN PSEUDOHYPOPARATHYROIDISM
Authors: Wolfsdorf Joseph I. , Rosenfield Robert L. , Fang Victor S. , Kobayashi Ryoji , Razdan Avtar K. , Kim Moon H.
Published: December 2008

A patient with classical Albright's pseudohypoparathyroidism was investigated because of oligomenorrhoea. Hypo-oestrogenism was associated with elevated basal gonadotrophin values [mean basal serum LH and FSH were 272±84 (sd) ng/ml and 593±83 ng/ml, respectively (normal ≦ 220 and ≦ 400, respectively)]. The response to gonadotrophin releasing hormone (Gn-RH) was exaggerated, with maximal LH and FSH increments of 1688 and 458 ng/ml, respectively. These results and the findings on ovarian biopsy were compatible with partial ovarian resistance to gonadotrophins. This resistance could be overcome by administration of human menopausal gonadotrophins. This is the first evidence for gonadotrophin resistance in pseudohypoparathyroidism. The plasma cyclic adenosine-3′,5′-monophosphate response to glucagon administration by two different protocols was about 70% that of normal control subjects. Other endocrine glands whose responses to hormones are mediated via the adenylate cyclase system evidenced minor abnormalities of questionable significance. This indirect evidence is compatible with a more extensive defect in the adenylate cyclase system in pseudohypoparathyroidism than has hitherto been suspected.
ALDOSTERONE, CORTICOSTERONE, CORTISOL. II-DEOXYCORTISOL AND II-DEOXYCORTICOSTERONE CONCENTRATIONS IN THE BLOOD OF CHRONICALLY CANNULATED OVINE FOETUSES: EFFECT OF ACTH
Authors: Brown Elizabeth H. , Coghlan J. P. , Hardy K. J. , Wintour E. Marelyn
Published: December 2008

Aldosterone, corticosterone, cortisol, 11-deoxycortisol and 11-deoxycorticosterone were measured, using a double isotope dilution derivative assay, in whole blood samples of ovine foetuses bearing chronic vascular cannulae. All values are quoted as mean ± standard error of mean. n = number of samples. Parturition occurred at 142–152 days. The concentration of aldosterone (ng/100 ml blood) was 8.7 ± 2.5 at 100–109 days, (n = 8), 4.4 ± 1.2 at 110–140 days (n = 32) and 11.5 ± 2.0 (n = 6) at 140 days until term. The value in unstressed, sodium replete pregnant sheep was 1.2±0.4 (n = 12). Neither corticosterone nor 11-deoxycortisol concentrations varied throughout gestation and were respectively 0.08 ± 0.02 and 0.03 ± 0.04 μg/100 ml blood in 56 samples. These values are essentially the same as those of pregnant, unstressed sheep. Total blood cortisol concentration was 0.10 ± 0.01 μg/100 ml in 38 samples from foetuses younger than 135 days, which is lower than the value for pregnant, unstressed sheep of 0.43 ± 0.07 (n = 34). Cortisol values rose after 135 days to reach 0.93 ± 0.3 (n = 7) after 140 days. The concentration of 11-deoxycorticosterone was 33.8 ± 8.0 ng/100 ml blood (n = 7) in the period 100–109 days, then decreased to 18.7 ± 4.4 (n = 45) from 110 days to term. The concentration in unstressed pregnant sheep was 26.3 ± 10 (n = 10) which is higher than non-pregnant sheep 2.33 ± 0.65 (n = 30). Infusions of ACTH (Synacthen®) 5 IU/h for 90 min had no consistent effect on the peripheral blood concentration of aldosterone, 11-deoxycorticosterone or 11-deoxycortisol at any stage, but elevated corticosterone values significantly (P < 0.01) in all foetuses. Cortisol concentrations were significantly elevated (P < 0.05) in foetuses of 135 days gestation or older.
THE EFFECTS OF LH, ADRENALINE AND NORADRENALINE ON TESTICULAR BLOOD FLOW AND PLASMA TESTOSTERONE CONCENTRATIONS IN ANAESTHETIZED RATS
Authors: Damber J.-E. , Janson P. O.
Published: December 2008

The acute effects of a 20 min constant rate intra-arterial infusion of LH and catecholamines on testicular blood flow and plasma testosterone concentrations were examined in sodium pentobarbitone anaesthetized rats. Ovine LH (2.5 μg/min) elicited a 6-fold increase in testosterone concentration and a significant decrease of testicular vascular resistance. Nor-adrenaline and adrenaline (0.4 μg/min) caused significant depressions in the plasma testosterone levels. The catecholamines induced no absolute changes in testicular blood flow but noradrenaline caused an increase in testicular vascular resistance. It was concluded that the catecholamine induced reductions in testosterone concentrations were not due to a vascular effect on the testis.
BROMOCRIPTINE TREATMENT OF 42 HYPERPROLACTINAEMIC WOMEN WITH SECONDARY AMENORRHOEA
Authors: Bergh Torbjörn , Nillius Sven Johan , Wide Leif
Published: December 2008

Bromocriptine therapy was given to 42 amenorrhoeic women with hyperprolactinaemia. Radiological signs of a pituitary tumour were seen in 24 women (57 per cent). During treatment the prolactin concentrations rapidly decreased towards normal in all the women and ovulation returned in all but two of the women after 5.5 weeks, on average. One of the non-responders had previously undergone transfrontal hypophysectomy. Defect luteal function was observed during the first ovulatory cycle in 51 per cent of the women, while 90 per cent had a normal luteal phase after the second ovulation. Twenty-one of the 22 women, who attempted to become pregnant, conceived and experienced a total of 27 pregnancies, of which 6 ended in abortion. Eleven of the 22 infertile women had radiological signs of a pituitary tumour. None of them was pre-treated with irradiation or surgery. Clinical signs of tumour enlargement during pregnancy were seen in 2 of the 11 women. Visual field defects developed during pregnancy in one woman, but re-institution of bromocriptine improved the visual impairment and the pregnancy could be completed at full term. Another tumour patient, who had an uneventful pregnancy, showed signs of tumour growth at the post-partum sellar X-ray. None of 10 women with normal pituitary radiology showed symptoms or signs of tumour enlargement during pregnancy, but post-partum the pituitary fossa was found to have increased in size and become asymmetric in one woman. Prolonged bromocriptine therapy reversed oestrogen deficiency symptoms in the non-infertile women by restoring normal gonadal function and improved libido and general well-being. Whether long-term bromocriptine therapy inhibits further growth or even causes regression of prolactin secreting pituitary tumours is still an open question. To sum up, bromocriptine is the drug of choice for treatment of amenorrhoea and infertility due to hyperprolactinaemia.
EFFECTS OF TWO ANALGESIC OPIATES (METHADONE AND PENTAZOCINE) ON THE SERUM PROLACTIN LEVELS IN BREAST CANCER
Authors: Rolandi E. , Barreca T.
Published: December 2008

In 18 female patients affected by advanced breast cancer, the serum prolactin (PRL) levels have been determined under basal conditions and after the administration of analgesic opiates such as methadone and pentazocine. A significant increase of prolactin serum values was found after the use of both drugs. This finding is considered to be of clinical importance.
RELATIONSHIP BETWEEN PEROXIDASE ACTIVITY AND SERUM TSH, T4 AND T3 LEVELS IN RATS IN THE COURSE OF IODINE DEFICIENCY
Authors: Nataf B. M. , Fragu P. , Othman S. Ben
Published: December 2008

The relationship between peroxidase activity and serum TSH, T4 and T3 levels was investigated in the course of iodine deficiency in rats. Rats were maintained either on a control diet with a relatively high iodine content (600 μg/kg of 127I), or on a low iodine diet (30 μg/kg of 127I). Twenty days after the low iodine treatment, the thyroid iodine [127I] concentration was half that of control value (647 ± 52 and 1241 ± 72 μg/g of wet weight, respectively). However, no significant changes in serum T4, T3, TSH were found at 20 days even though an early increase in peroxidase activity was observed. It was only at 35 days of iodine deficiency, when the concentration of iodine in the gland averaged 260 μg/g of wet weight that serum T4 and TSH levels started to be significantly modified. From day 35 to day 70, a significant and progressive decrease of plasma T4 concentration was observed, and it levelled off thereafter. The changes of serum T3 were much smaller than those of T4. A significant increase in serum TSH level was noted at 35 days. Thereafter TSH levels increased rapidly and progressively (205 % increase over control at 70 days and 643 % at 80 days). From day 35 until day 80 of the low iodine treatment, the thyroid peroxidase activity and the serum TSH level varied concomitantly.

Our results suggest that for an iodine content between 5 and 2 μg per thyroid gland, the high cellular peroxidase activity observed could be correlated with an increase in circulating TSH, due to a decrease of T4. In contrast, in the early period of iodine deficiency, no correlation was found between peroxidase activity and serum T4, T3 and TSH levels.
THYROID IODINE METABOLISM IN STREPTOZOTOCIN-DIABETIC RATS
Authors: Jolín Trinidad , González Concepción , González Margarita
Published: December 2008

Experiments have been performed to assess the effect of diabetes on thyroid function in male Wistar rats. Diabetes was induced by a single streptozotocin injection. As compared to normals, the diabetic rats displayed: 1) decreased rate of stable iodine uptake by the gland, as measured with a double isotopic technique; 2) decreased in vitro iodide uptake by the thyroid; 3) decreased T/S [I-] ratio after acute treatment with propylthiouracil; and 4) alteration in the distribution of labelled iodoamino acids in the gland. Furthermore, diabetic rats maintained lower plasma TSH levels than normals, in spite of the fact that plasma PBI concentration was slightly but consistently lower in diabetic than in normals, and that the pituitary TSH content was not affected by the lack of normal insulin levels.

Injections of TSH (5 U/100 g body weight/day) for 5 days, into diabetic rats caused a return of thyroid function toward normal. Insulin administration resulted in an increase of thyroid weight, an increase of thyroid function, and an increase of pituitary TSH secretion in diabetic rats after the daily injection of 1, 2 or 3 U/100 g body weight/day for 7 days. The decreased pituitary TSH secretion in diabetic rats might involve a disturbance in the feed-back relationship between the thyroid and the pituitary, although other mechanisms could be involved.