bluuebunny/crossref_metadata_2025_split huggingface dataset:
INACTIVATION OF THYROTROPHIN RELEASING HORMONE BY HUMAN AND RAT SERUM
Authors: Visser T. J. , Klootwijk W. , Docter R. , Hennemann G. 
Published: December 2008

ABSTRACT
The inactivation of thyrotrophin releasing hormone (pGlu-His-Pro-NH2, TRH) and its deamidated analogue pGlu-His-Pro-OH (TRH-OH) in human and rat serum has been studied using specific radioimmunoassays. No difference was apparent between human and rat serum with regard to proteolytic activity towards TRH and TRH-OH. It was found that the inactivation of both peptides is a saturable process. The disappearance of TRH was clearly inhibited by TRH-OH, luteinizing hormone-releasing hormone and dithiothreitol. The suppressive action of these compounds was observed to be dependent on their concentration. Proline and EDTA showed little inhibiting activity. Proline amide and pyroglutamic acid left the reaction unaffected. In no single instance could any production of TRH-OH from TRH be demonstrated.
DISCORDANT PATTERNS OF HYPERPROLACTINAEMIA AND GALACTORRHOEA IN SECONDARY AMENORRHOEA
Authors: Seppälä M. , Lehtovirta P. , Ranta T. 
Published: December 2008

ABSTRACT
Hyperprolactinaemia occurred in 40 of 123 unselected patients (33%) with functional secondary amenorrhoea. Galactorrhoea was present only in 15 of these patients (38 %). On the other hand, galactorrhoea was found in 10 of 83 euprolactinaemic patients (12%). The frequency and severity of hyperprolactinaemia and galactorrhoea dissociated in various forms of amenorrhoea. Anorexia nervosa was characterized by euprolactinaemia and the absence of galactorrhoea. Self-induced weight loss resulted in amenorrhoea with a moderate degree of hyperprolactinaemia in 23 % of the cases. Yet, galactorrhoea was uncommon (1.6 %). Amenorrhoea following stress was also associated with moderate hyperprolactinaemia in 31 % of patients and a low frequency of galactorrhoea. By contrast, both hyperprolactinaemia and galactorrhoea occurred more frequently (36 %) and were more severe in patients who had post-pill amenorrhoea, but still 50 % of hyperprolactinaemic patients had no galactorrhoea and 28 % of euprolactinaemic patients had galactorrhoea. This discordance was accentuated in those patients who had been pregnant even if pregnancy did not immediately precede amenorrhoea. Galactorrhoea (63 %) and hyperprolactinaemia (36 %) were common in these patients and very high serum prolactin values were sometimes seen. Our results point to different mechanisms involved in the regulation of hypothalamic pituitary function and breast secretion in various forms of secondary amenorrhoea, and they may help select patients in whom the prolactin assay is likely to identify indication for specific treatment.
STUDIES ON THE PATTERN OF CIRCULATING STEROIDS IN THE NORMAL MENSTRUAL CYCLE
Authors: Nuñez M. , Aedo A.-R. , Landgren B.-M. , Cekan S. Z. , Diczfalusy E. 
Published: December 2008

ABSTRACT
The plasma levels of oestrone sulphate, oestradiol sulphate, oestrone and oestradiol were studied in samples collected daily from 8 normally menstruating women throughout a complete menstrual cycle. In order to ascertain the normality of the cycles studied, LH and progesterone were also determined daily. All compounds were measured by radioimmunoassay, the sulphates after solvolysis. For the determination of the sulphates a procedure was developed which fulfilled the recognized criteria of reliability.
Both oestrone sulphate and oestradiol sulphate displayed a marked cyclic pattern, similar to and correlated with that of oestrone and oestradiol, i. e., all 4 oestrogens exhibited a marked mid-cycle peak and elevated levels during the luteal phase. The mean levels of the steroid moiety of oestrone sulphate were 10–15 times higher than those of oestrone, and 2–3 times higher than those of the 3 other oestrogens together. On the other hand, the mean levels of oestradiol sulphate were 1.2 to 4 times lower than those of oestradiol.
The ratios of the levels of various pairs of oestrogens were calculated. All pairs showed a considerable change of ratios from the early follicular phase to mid-cycle. This demonstrates that the mutual metabolic equilibria of oestrogens are different in various phases of the cycle.
Daily measurements of oestrone sulphate and oestradiol sulphate do not seem to provide a better index to predict the day of ovulation than the characteristic changes in progesterone and 17-hydroxyprogesterone levels.
PERPHENAZINE-INDUCED PROLACTIN SECRETION IN ACROMEGALY
Authors: Buckman Maire T. , Peake Glenn T. 
Published: December 2008

ABSTRACT
Phenothiazine-induced prolactin secretion was studied in 6 untreated acromegalic patients with radiographic evidence of enlarged sella turcica and responses correlated with other parameters of anterior pituitary function. Five patients had normal basal serum prolactin levels and in one it was elevated. In patients with normal basal prolactin concentrations, prolactin responsiveness to perphenazine (Trilafon®) ingestion was normal in 3 and blunted in 2. The single patient with hyperprolactinaemia also demonstrated perphenazine unresponsiveness. Evaluation of the pituitary-adrenal, pituitary-thyroidal and pituitary-gonadal axes revealed a spectrum of hormonal deficiencies. Of the 3 patients with normal perphenazine-induced prolactin secretion, one had gonadotrophin deficiency, another TSH deficiency, and the remaining patient had no other demonstrable abnormality in pituitary function. In 2 patients prolactin unresponsiveness was not associated with other pituitary hormonal deficiencies. The sole patient with hyperprolactinaemia also had hypogonadotrophic hypogonadism. Thus, in acromegalic patients with radiographic evidence of enlarged sella turcicas, prolactin unresponsiveness was the commonest other abnormality observed in anterior pituitary function. In 2 patients normal prolactin responses, however, were associated with additional deficiencies. To establish pituitary functional capacity in acromegaly, the status of each pituitary hormone must be evaluated separately.
THYROLIBERIN AND GONADOLIBERIN TESTS DURING PREGNANCY AND THE PUERPERIUM
Authors: Vandalem J. L. , Pirens G. , Hennen G. , Gaspard U. 
Published: December 2008

ABSTRACT
Highly specific and sensitive radioimmunoassays for HTSH, HFSH and HLH have been used in order to investigate pituitary thyrotrophic and gonadotrophic functions of pregnant and puerperal women. The radioimmunoassay system for HFSH, using reagents prepared in our laboratory, is described.
Thirty-three women were studied during pregnancy and post-partum. Forty-one TRH tests were performed. Basal levels of TSH, and increase in serum TSH after intravenous injection of TRH were similar in pregnant and puerperal women and in a control group. Thirty-three LH-RH tests were also performed. Basal levels of LH and FSH remained undetectable throughout pregnancy and in early puerperium. Furthermore, after intravenous injection of LH-RH neither LH nor FSH activity could be detected.
It has thus been demonstrated that pituitary responsiveness to TRH during pregnancy and the puerperium is similar to that of non-pregnant young women. In contrast, a complete cessation of pituitary gonadotrophic functions is observed during the same period.
INFLUENCE OF OESTROGEN ADMINISTRATION IN VIVO AND IN VITRO ON THE RELEASE AND SYNTHESIS OF LH AND FSH FROM INCUBATED PITUITARIES
Authors: Apfelbaum Marta E. , Taleisnik S. 
Published: December 2008

ABSTRACT
The effect of oestrogen on the release and synthesis of LH and FSH was studied in rat adenohypophyses incubated for a period of 4 h in flasks containing 1 ml Eagle's medium. One hemipituitary was used as the experimental gland and the other half served as a control.
The spontaneous release of LH and FSH by glands from ovarectomized rats was not affected by oestradiol-17β added to the incubation medium in doses of 55, 166, 500 and 1500 ng/ml. The amount of hormones released by pituitaries from spayed rats injected with oestradiol benzoate (2.5, 5.0 and 10.0 μg/rat) 2 h or 24 h before killing the animals too was not different from that of oil-injected rats. Neither was there any effect of oestrogen when added to the incubation medium of glands from oestrogen-pre-treated rats.
However, the concentration of LH and FSH in the gland increased when oestrogen was added to the incubation medium, indicating enhanced synthesis. The effect was dose-dependent up to the dose of 500 ng/ml oestradiol but a dose of 1500 ng/ml was less effective. Increased synthesis of LH but not of FSH was also observed in incubated glands from rats injected with oestrogen 24 h before death, but no changes were seen in those of rats killed 2 h after treatment. Additive effects occurred with the in vivo and in vitro steroid treatment.
These results indicate that oestrogen favours synthesis of LH and FSH in cultured pituitaries, without affecting gonadotrophin secretion and that the changes induced in the in situ gland by oestrogen treatment are reflected by their in vitro activity.
INFLUENCE OF OESTROGEN ADMINISTRATION IN VIVO AND IN VITRO ON THE RELEASE AND SYNTHESIS OF PROLACTIN FROM INCUBATED PITUITARIES
Authors: Apfelbaum Marta E. , Taleisnik S. 
Published: December 2008

ABSTRACT
The release and synthesis of prolactin were studied in incubated adenohypophyses from ovariectomized rats. After a 4 h incubation period the prolactin concentration in the medium markedly increased whereas that in the gland was reduced. However, the concentration of prolactin in the system, tissue plus medium, after 4 h was almost twice as much as that present at the beginning of incubation indicating spontaneous synthesis. This spontaneous release and synthesis of prolactin was greatly increased in incubated glands from ovariectomized oestrogen-treated rats. Oestradiol benzoate was injected in doses of 2.5, 5.0 or 10.0 μg/rat 2 or 24 h before killing the animals. Lower effects were obtained in glands from 2 h-oestradiol-pre-treated rats than from 24 h-oestradiol-primed rats. Oestradiol-17β (55, 166, 500 and 1500 ng/ml) added to the incubation medium also enhanced the release and synthesis of prolactin and the effect was more marked in glands from oestrogen injected rats than in those of non-treated animals. The increase was dose-related although the higher doses were less effective.
These results provide further evidence of the effect of oestrogen on the release and synthesis of prolactin by a direct action on the pituitary gland. They also show that oestradiol pre-treatment in vivo increase the response of the prolactin cells towards oestradiol in vitro.
HYPERCALCAEMIA DISCRIMINATION INDEX: A MULTIVARIATE ANALYSIS OF PARATHYROID FUNCTION IN 107 HYPERCALCAEMIC PATIENTS
Authors: Transbø I. , Jørgensen F. Schønau , Hornum I. , Keiding N. 
Published: December 2008

ABSTRACT
The limited usefulness of radioimmunoassays of parathyroid hormone in the differential diagnosis of hypercalcaemia invites the use of methods measuring effects of parathyroid hormone (PTH). Data from 4–5-day metabolic studies in 107 hypercalcaemic patients (78 retrospective and 29 prospective cases) were combined in a hypercalcaemia discrimination index (HDI). HDI = (urine calcium (mg/24 h) x 100 x serum phosphate (mg/100 ml))/(serum total calcium (mg/100 ml) x 24-h clearance of creatinine (ml/min)) expresses in one figure the combined actions of PTH on the renal handling of calcium and on serum phosphate. A multivariate analysis confirmed that HDI offered optimal discrimination. An identical discrimination was observed in the prospective series. In the complete series HDI = 137 was the optimal discrimination point. Classification of the patients as having hyperparathyroidism (HPT) or pseudohyperparathyroidism (P-HPT) (< 137) or non-parathyroid hypercalcaemia (NON-PTH) (≧ 137) corresponded in 100 out of 107 patients (93.5%) with the final clinical diagnosis. The effects on HDI of sex, age, season, urine losses, high calcium intake and use of thiazides were also evaluated.
HDI appears to be a valuable tool in the endocrine evaluation of hypercalcaemic patients. Used in combination with radioimmunoassays measuring genuine but not ectopic PTH HDI may serve to classify hypercalcaemic patients within the following 3 subgroups: HPT, P-HPT and NON-PTH.
COMPARISON BETWEEN THE 5,6-CIS AND 5,6-TRANS ISOMERS OF 25-HYDROXYVITAMIN D3 IN CHRONIC HYPOPARATHYROIDISM
Authors: Offermann Gerd , Kraft Dieter 
Published: December 2008

ABSTRACT
Five patients with chronic post-operative hypoparathyroidism were treated with 450 μg/day 5,6-trans-25-hydroxyvitamin D3 (5,6-trans-25OHD3) for 14 days, and the treatment was continued with 150 μg/day for one year. At the end of this period the patients received 450 μg/day 5,6-cis-25-hydroxyvitamin D3 (5,6-cis-25OHD3) for 14 days. Comparison of the effects of both isomers revealed a similar ability to enhance intestinal calcium absorption and to normalize serum calcium; serum phosphate and alkaline phosphatase, however, remained unaffected. Urinary phosphate and hydroxyproline excretion decreased on the cis-isomer and increased on the trans-isomer. During treatment with the lower dose of 5,6-trans-25OHD3 intestinal calcium absorption remained in the normal range for one year, whereas the serum calcium decreased to the levels observed before administration of 450 μg/day within 6 weeks. The results suggest that in hypoparathyroidism 5,6-cis-25OHD3 and 5,6-trans-25OHD3 are equally effective on serum calcium and on intestinal calcium absorption, but that their mode of action on renal phosphate handling and on calcium release from bone is different.
MAMMARY GROWTH AND FUNCTION AND PITUITARY PROLACTIN SECRETION IN FEMALE NUDE MICE
Authors: Nagasawa Hiroshi , Yanai Reiko 
Published: December 2008

ABSTRACT
Mammary structural growth in the wholemount preparation, content and synthesis of mammary DNA and RNA estimated by the incorporation of [3H]thymidine and [14C]uridine, pituitary and plasma levels of prolactin and weights and histological structures of some organs of female nude mice (nu/nu) were compared to those of the control (nu/+) with the same genetical background (BALB/c). Both at 3 months of age and on day 1 of lactation, the weights per 100 g body weight of adrenals, spleen and liver of nu/nu mice were significantly higher than those of nu/+ mice. Mammary growth stimulation by pituitary graft was much more marked in nu/nu mice than in nu/+ mice. Slight differences between groups were found in the pituitary and plasma levels of prolactin, in the histological structures of ovaries as well as of the adrenals and thyroids and in the pattern of oestrous cycles. On the other hand, the content and synthesis of mammary DNA at 3 months of age and content and synthesis of both DNA and RNA and RNA/DNA ratio on day 1 of lactation were significantly higher in nu/+ mice than in nu/nu mice. All findings suggest that thymus deficient immunosuppression has deleterious effects on mammary growth and function without its alteration in the secretion of prolactin and oestrogen and probably through its decrease in mammary responsiveness to mammotrophins.
INFLUENCE OF GROWTH HORMONE ON SPLANCHNIC GLUCOSE PRODUCTION IN MAN
Authors: Adamson Ulf , Wahren John , Cerasi Erol 
Published: December 2008

ABSTRACT
The influence of growth hormone (GH) on splanchnic exchange of glucose and glucogenic precursors was investigated in 11 healthy subjects using the hepatic venous catheter technique. GH was infused intravenously at the rate of 40 μg/kg body weight over 30 min. A peak plasma GH level of 219 ± 25 ng/ml was obtained. During GH infusion the blood glucose concentration fell slightly but significantly. In addition, the splanchnic glucose output decreased by approximately 35–40% during and immediately after GH infusion. The splanchnic uptake of the glucogenic precursors lactate, pyruvate, alanine and glycerol was not significantly influenced by GH infusion. The arterial concentration of insulin fell slightly, while the glucagon level remained unchanged during the infusion but decreased 20–30 min after the end of GH infusion. Indirect estimates of the peripheral glucose utilization indicated that GH infusion was accompanied by a 25% reduction in peripheral glucose uptake.
The influence of GH on the inhibition of splanchnic glucose output induced by endogenous insulin in connection with intravenous glucose infusion (2 mg/kg/min) was studied in 6 subjects. GH infusion, given 60 min before the onset of glucose administration, did not significantly modify the splanchnic glucose output response to glucose infusion.
It is concluded that a) GH may exert a direct inhibitory influence on splanchnic glucose output which is independent of changes in insulin and glucagon, b) hepatic glycogenolysis, but probably not gluconeogenesis is influenced by GH, and c) GH infusion is accompanied by decreased peripheral utilization of glucose.
SIMULTANEOUS DETERMINATION OF THE CONTENT OF SEROTONIN, DOPAMINE, NORADRENALINE AND ADRENALINE IN PANCREATIC ISLETS ISOLATED FROM FED AND STARVED MICE
Authors: Hansen S. E. , Hedeskov C. J. 
Published: December 2008

ABSTRACT
A highly sensitive double isotope method for the simultaneous determination of serotonin, dopamine, noradrenaline and adrenaline has been developed. Advantages and limitations of the method are discussed.
The mentioned biogenic amines are all present in isolated pancreatic islet tissue from albino mice in concentrations ranging from approximately 5-30 μmol per kg wet weight (0.8–5 × 10−3 pmol/ng DNA). A somewhat higher content of these amines, especially dopamine, was found in pancreatic acinar tissue.
The hypothesis that the impaired glucose-induced insulin secretion during starvation partly is caused by an increased content of biogenic amines in the pancreatic islets was not supported by our experiments which showed an unchanged islet content of these amines after 48 h starvation.
AN IN VIVO MODEL FOR TESTING INHIBITION OF ARGININE-INDUCED INSULIN AND GLUCAGON RELEASE BY SOMATOSTATIN ANALOGS
Authors: Gordin Ariel , Meyers Chester , Arimura Akira , Coy David H. , Schally Andrew V. 
Published: December 2008

ABSTRACT
An animal model for testing the in vivo potency of somatostatin analogs in inhibiting the release of insulin and glucagon is described. The secretion of these pancreatic hormones was stimulated in rat by infusion of arginine. The plasma insulin level increased almost to a maximum after an infusion of 10 min, while plasma glucagon rose more slowly, reaching its maximum only after a 30 min infusion. Concomitant infusion of graded doses of somatostatin (2.5, 10, 40 and 160 μg/100 g BW) for 30 min inhibited both insulin and glucagon release in a dose-dependent manner, enabling us to test somatostatin analogs for insulin and glucagon-suppressive activity in a semi-quantitative manner. Using this animal model, 3 analogs of somatostatin, [D-Cys14]-, [Ala2, D-Cys14]- and [D-Trp8, D-Cys14]somatostatin were tested in a 4-point assay. They all showed dissociated activity in inhibiting the secretion of glucagon more than that of insulin.
SPECIES DIFFERENCES IN STEROIDOGENESIS FOLLOWING THE IN VITRO INCUBATION OF DECAPSULATED TESTES
Authors: de la Torre B. , Hedman M. , Diczfalusy E. 
Published: December 2008

ABSTRACT
Decapsulated testes of rats, guinea pigs and rabbits were incubated with or without labelled precursors and the steroids formed under various experimental conditions were analysed. Also a decapsulated human testis was incubated with labelled acetate.
Cholesterol, testosterone and androstenedione were isolated in a radiochemically homogeneous form following the incubation of carbon-14-labelled sodium acetate with decapsulated testes of all 3 animal species. No other labelled steroid was detected following the incubation of rat testes. Guinea pig testes also converted labelled acetate to pregnenolone. Rabbit and human testes converted labelled acetate to cholesterol, pregnenolone, dehydroepiandrosterone, androstenediol, testosterone and androstenedione. When decapsulated testes of rats, guinea pigs and rabbits were incubated with carbon-14 labelled pregnenolone as a precursor, radiochemically homogeneous progesterone, 17-hydroxypregnenolone, dehydroepiandroster-one, androstenediol, androstenedione and testosterone were isolated in each experiment.
Using radioimmunoassay techniques, preformed steroids together with steroids formed from endogenous precursors were analysed following the incubation of rat, guinea pig and rabbit testes in the absence and in the presence of human chorionic gonadotrophin (HCG).
Marked (seasonal?) variations were observed between the results of experiments conducted at different times. Incubation of guinea pig testes in the absence as well as in the presence of HCG resulted in a major increase in pregnenolone levels. No such finding was encountered when rat and rabbit testes were incubated. The addition of HCG resulted in at least a 10-fold increase in testosterone formation by the testes of all three species. The addition of HCG to the incubation medium induced a marked rise in dihydrotestosterone levels in the rabbit testes but had no effect whatsoever on the levels of this steroid in guinea pig testes.
It is concluded that considerable species differences exist in the steroid metabolism of decapsulated testes incubated in vitro.
THE EFFECTS OF THE DOPAMINE AGONIST, LERGOTRILE MESYLATE, ON PROLACTIN SECRETION IN WOMEN
Authors: Leebaw Wayne , Lee Louyse , Woolf Paul 
Published: December 2008

ABSTRACT
Lergotrile mesylate, an ergot derivative and dopamine agonist, decreases basal (single sample) prolactin levels and blunts phenothiazine-mediated prolactin release. To more thoroughly evaluate the effect of this drug, we measured prolactin and growth hormone concentrations hourly over 24 h in 5 healthy women and during insulin (0.1 U/kg) induced hypoglycaemia (ITT) in 6 women before and during 2-day lergotrile treatment. Lergotrile (4.0 to 6.0 mg/day) significantly decreased the mean 24-hour prolactin concentration in 3 and abolished the nocturnal rise in 4. For the entire group, the mean nocturnal levels (2400–0700 hours) were 24.0 #x00B1;7.5 vs 14.4 ± 3.9 ng/ml during waking (0800–2300 hours) pre-lergotrile (P<0.05), while during therapy the concentrations were 8.9 ± 2.8 vs 8.0 ± 1.4 ng/ml (NS), respectively. The prolactin response to ITT was also significantly inhibited by lergotrile with the peak response reduced from 78.2 ± 35.1 ng/ml to 9.0 ± 3.6 ng/ml (P < 0.05). The mean 24-hour growth hormone concentration was unchanged during therapy, and there was no significant effect on the GH response during ITT.
The effects of chronic therapy with lergotrile (8 mg/day for 6 weeks) were studied in one acromegalic patient with elevated levels of prolactin and growth hormone. Her prolactin concentration fell from 452.2 ± 8.0 to 216 ng/ml, while GH declined from 23.8 ± 1.3 to 14.8 ng/ml.
Lergotrile mesylate effectively lowers mean 24-hour prolactin concentrations (determined hourly) and completely abolishes both nocturnal and hypoglycaemia-mediated prolactin release. This drug may also be beneficial in the therapy of acromegaly.