bluuebunny/crossref_metadata_2025_split huggingface dataset:
Receptor mediated gonadotropin action in the ovary
Authors: Azhar Salman , Menon Mangaladevi , Menon K. M. J. 
Published: December 2008

Abstract.
The role of macromolecular synthesis in gonadotrophin, cholera enterotoxin and cAMP stimulated progesterone production by rat ovarian cells has been investigated. Both progesterone and cAMP accumulation were increased by cholera enterotoxin in a concentration dependent manner. Incubation of cells with cholera enterotoxin resulted in a 10–20-fold increase in cAMP levels. The effect was observed 15–20 min after addition of toxin. In contrast, stimulation of cAMP levels by hCG was immediate. Cyclic AMP production in response to trophic hormone reached a maximum at 60 min, while maximum stimulation in response to toxin was attained after 2–3 h of incubation. Activation of steroidogenesis in response to both cholera enterotoxin and gonadotrophin showed a lag period. hCG and cholera enterotoxin stimulated a maximum amount of progesterone production after 2 and 3 h of incubation, respectively. With the maximum effective concentration of hCG, addition of choleragen did not result in any further increase in steroidogenesis. Similarly 8 Br-cAMP and Bt2-cAMP also stimulated steroidogenesis.
Progesterone response to cholera enterotoxin, hCG, LH, 8 Br-cAMP and Bt2-cAMP was completely blocked by incubation of cells with cordycepin, actinomycin D, emetine and cycloheximide. That the specific effect of these inhibitors was on macromolecular synthesis rather than a general non-specific toxic effect was demonstrated by inhibition of [3H]proline incorporation and the lack of effect of these inhibitors on cAMP production in response to hCG, LH and cholera enterotoxin. Emetine (10 μm) and cycloheximide (50 μm) inhibited cholera enterotoxin and hCG stimulated progesterone production when added at different time points during the incubation. Cordycepin (250 μm) also blocked toxin and hCG induced steroidogenesis in a similar manner. The concentrations of cordycepin, cycloheximide and emetine required to completely block hCG stimulated progesterone production were 250, 50, and 5 μm, respectively. Similar concentrations of these inhibitors also maximally inhibited 8 Br-cAMP and cholera enterotoxin stimulated steroidogenesis. No effect of these inhibitors on basal production of progesterone was observed. These results suggest that gonadotrophin induced progesterone synthesis is dependent upon the continued synthesis of short lived mRNA and protein(s).
Adrenal corticosteroids and immunoreactive ACTH in chronically cannulated ovine foetuses with bilateral adrenalectomy
Authors: Wintour E. Marelyn , Coghlan J. P. , Hardy K. H. , Hennessy D. P. , Lingwood Barbara E. , Scoggins B. A. 
Published: December 2008

Abstract.
The adrenal fails to develop in the hypophysectomised ovine foetus but adrenal growth, maturation and increased cortisol secretion occur in the intact foetus whilst plasma immunoreactive ACTH remains at a constant value. The presence of a feedback relationship between foetal adrenal and pituitary was examined in 8 ovine foetuses which were bilaterally adrenalectomised (adrx.) at the time of implantation of catheters in the carotid artery and jugular vein (90–127 days of gestation). Ten chronically cannulated foetuses served as controls. Gestation length in these sheep was 147 ± 5 days. Plasma immunoreactive (IR) ACTH (IR.ACTH) was measured with a Sorin Biomedica kit. The antibody cross-reacts with ACTH1–39, and ACTH1–24, but not with ACTH1–13, ACTH18–39, β-LPH or β-endorphin. Cortisol (F) and corticosterone (B) were measured by a double isotope dilution derivative assay. In intact foetuses the IR.ACTH was 69.6 ± 7.1 pg/ml (mean ± sem, n = 37) until the day before parturition when values increased to 326 ± 60 pg/ml (n = 6). In adrx. foetuses of 91–121. 122–135 and > 136 days gestation the IR.ACTH values were 50.3 ± 4 (n = 14), 444 ± 46 (n = 26) and 1155 ± 175 (n = 6) pg/ml, respectively. The foetal F and B concentrations were 0.12 ± 0.027 μg/100 ml and 40 ± 6 ng/100 ml (n = 14), respectively, in adrx. foetuses. These values are not significantly different from those in intact foetuses younger than 135 days. The mean F and B concentrations in adrx. foetuses were 22 ± 4.3% (n = 14) and 49 ± 5.4% (n = 14) of the respective maternal values. In summary prior to 120 days the IR.ACTH, F and B concentrations are similar in intact and adrx. foetuses. After 122 days the IR.ACTH secretion by the foetal pituitary first begins to exhibit a feedback relationship with some adrenal secretion (?not F or B) and after 130–135 days some subtle change in pituitary sensitivity to F and/or B may operate. It is suggested that about 120 days a significant alteration in the foetal pituitary capacity for ACTH synthesis occurs.
Pituitary and gonadal function in prepubertal and pubertal cryptorchidism
Authors: Okuyama A. , Itatani H. , Mizutani S. , Sonoda T. , Aono T. , Matsumoto K. 
Published: December 2008

Abstract.
LRH and hCG tests were performed in 35 prepubertal and 35 pubertal boys with unilateral or bilateral cryptorchidism to examine the pituitary and gonadal function. Twenty-one normal boys were also examined as controls. In the prepubertal group, distinct increases in serum LH, FSH and testosterone levels by LRH and hCG tests were found in all of the normal and unilateral cryptorchid boys. However, no or very little response was observed in 4 out of 17 boys with bilateral cryptorchidism.
In the pubertal group, serum levels of LH, FSH and testosterone in normal boys, in unilateral and in bilateral cryptorchid boys were evidently higher than those in the prepubertal group, and distinct or moderate responses by the LRH and hCG tests were found in all boys examined. Although serum testosterone levels were similar in all groups, serum basal and peak gonadotrophin levels by the LRH test were significantly higher in bilateral cryptorchid boys than in normal and unilateral cryptorchid boys. The difference was more marked in FSH than in LH level. An elevated level of serum LH is suggestive of the hypofunction of not only the seminiferous tubules but also of the Leydig cells in cryptorchid testes.
Morning and evening human Leydig cell responses to hCG
Authors: Nankin H. R. , Murono E. , Lin T. , Osterman J. 
Published: December 2008

Abstract.
The present 72 h study compares the patterns of 17α-hydroxyprogesterone (17OHP) and testosterone responses to im hCG (40 IU/kg) injected at 09.00 h and on different occasions at 17.00 h in eight normal men. Basal a.m. steroid concentrations were significantly higher for both steroids (15% for testosterone and 52% for 17OHP). A peak (at 2 h and 3 h) and statistically significant nadir (at 5 h, 5.5 h and 6 h) response was found for each steroid in the a.m. studies, but in the p.m. studies the two steroids rose significantly at 2 h and remained plateaued through 6 h. Between 5 h and 6 h, and for the remainder of the morning and evening studies, the respective steroid concentrations and the patterns to the changes were the same. Between 6 h and 24 h both steroids rose further. 17OHP peaked at 24 h and 48 h, 3.2 times basal and declined at 72 h. Testosterone rose further between 24 h and 48 h, and was unchanged at 72 h. At the latter two times it averaged 2.2 fold basal values. hCG was detectable at 1 h, rose progressively to highest levels at 24 h, and declined thereafter — in similar fashion in the a.m. and p.m. studies.
The 'peak and nadir' responses occur within the first few hours of gonadotrophin stimulation begun in the morning and appear to be related to the time of day and do not appear to be the result of a biosynthetic block. This suggests a diurnal variation of human Leydig cell response. With intense, probably maximal, testis stimulation each steroid shows the same respective pattern and circulating concentrations between 5 h and 72 h in both the a.m. and p.m. studies.
The influence of sexual hormones on lipogenesis and lipolysis in rat fat cells
Authors: Hansen Finn Mølgaard , Fahmy Nibal , Nielsen Jens Høiriis 
Published: December 2008

Abstract.
The insulin-stimulated conversion of glucose to fatty acids (fatty acid synthesis) and the maximally norepinephrine-stimulated lipolysis were studied in isolated fat cells from normal male and female rats, ovariectomized rats and sexual hormone-treated normal and ovariectomized rats. The fatty acid synthesis and the lipolysis oscillated considerably more in fat cells from female rats than in fat cells from male rats. This was found to be due to the oestrous cycle, since the fatty acid synthesis was high in prooestrus and low in both oestrus and dioestrus, while the lipolysis was higher in oestrus and prooestrus than in dioestrus. Oestradiol treatment of both female and male rats and testosterone treatment of male rats for three days lowered the fatty acid synthesis and increased the lipolysis. The metabolic oscillation disappeared in ovariectomized rats, and the fat cells from these animals showed a metabolic pattern comparable with that found in prooestrus. Even when ovariectomized rats were treated with oestradiol or progesterone only three hours before the examination a significant lower fatty acid synthesis was found in oestradiol-treated animals compared with the progesterone-treated animals. Since these rats were fasted three hours before the experiments, the results were not due to differences in food intake. It is concluded that fat cell metabolism is influenced by sexual hormones. The results are compatible with the hypothesis that the variation in food intake due to sexual hormones is secondary to the metabolic changes.
Plasma pattern of immunoreactive ACTH in normal man and in patients with Nelson's syndrome
Authors: Thorén M. , Ajne M. , Hall K. 
Published: December 2008

Abstract.
A radioimmunoassay for ACTH determinations in human plasma was developed using an N-terminal antiserum. Plasma ACTH levels at 6 a.m. in 39 patients with normal pituitary-adrenal function were below 4 pmol/l in two individuals. The remaining had a mean of 32.7 ± 4 pmol/l (n = 37). Gel filtration on Sephadex G-50 medium and G-75 revealed that a high molecular weight immunoreactive ACTH was found in plasma from both normal individuals and patients with Nelson's syndrome. The stimulation of ACTH secretion with metyrapone (750 mg perorally) significantly increased the mean plasma levels of 1–39 ACTH after 3 h (from 0.9 to 6.6 pmol/l) in 10 healthy individuals. The level of the high molecular weight form remained constant. In one patient with Nelson's syndrome hydrocortisone iv (100 mg/h for 3 h) suppressed the total ACTH levels from 360 to 83 pmol/l following corticoid withdrawal on the previous evening, but did not affect the high molecular weight form of ACTH. The difference between the amounts of immunoreactive ACTH found in plasma from normal individuals and from patients with Nelson's syndrome was attributed to 1–39 ACTH.
Effect of treatment with bromocriptine on the size and activity of prolactin producing pituitary tumours
Authors: Sobrinho L. G. , Nunes M. C. , Calhaz-Jorge C. , Maurício J. C. , Santos M. A. 
Published: December 2008

Abstract.
Eleven consecutive patients with large prolactinomas were treated for 6 months with bromocriptine, (7.5 mg/day). Nine had invasion of the sphenoidal sinus, one a visual field defect and one a secondary trigeminal neuralgia. At the end of the treatment period 8 of the first 9 patients showed radiographical signs of bone remodelling and/or actual reduction of the tumour size. The last 2 patients had complete disappearance of their symptoms.
The remissions could be observed as early as 3 weeks after the start of the treatment. Two patients suffered acute, reversible (partial in one case) episodes of loss of vision during the study. During the treatment the prolactin values decreased in all patients to an average of 1.7% of the baseline levels. There was a steep rise in the serum prolactin concentrations after withdrawal of the drug. After one month there was a plateauing at a high level, although lower than basal level.
Libido and potency were restored in all 3 males studied. Two of the females experienced orgasm for the first time in their lives after some years of primary frigidity. It is concluded that bromocriptine reproducibly reduces the size of prolactinomas. This effect can be observed shortly after the beginning of the treatment and is at least partially reversible. Episodes of pituitary apoplexy may occur during the treatment of large tumours despite an otherwise favourable response.
Hypernatraemia, diabetes mellitus, hyperprolactinaemia, retarded growth and delayed puberty in a 14 year old girl. Effect of bromocriptine treatment
Authors: Christensen Niels Christian , Hagen Claus , Nielsen Meta Damkjær , Petersen Sten 
Published: December 2008

Abstract.
Investigations in a 14 year old girl with arrested growth for 2 years, delayed pubertal development, hypernatraemia without thirst, diabetes mellitus and hyperlipaemia are reported. The hypernatraemia was accompanied by a low vasopressin concentration with an abnormal response to thirst, high plasma renin but normal plasma aldosterone concentrations. Treatment with vasopressin and increased fluid intake decreased serum sodium levels. Serum gonadotrophins were low; GH response during an insulin tolerance test was subnormal and basal serum Prl concentration was elevated. Bone age, thyroid function and adrenal function were normal. After initiation of bromocriptine treatment her growth accelerated and regular menstruations commenced. The serum gonadotrophin levels increased and showed pulsatile release. A hypothalamic disorder is suggested, but no cerebral lesion could be demonstrated.
Pituitary-thyroidal function in children with β-thalassaemia major
Authors: Cavallo L. , Mautone A. , Altomare M. , Licciulli M. , Pascazio A. , Schettini F. 
Published: December 2008

Abstract.
Thyroid function was investigated in eleven β-thalassaemia major prepubertal children, 3–15 years old.
Basal serum levels and the levels during a TRH-test of TSH, T4, T3, and rT3 were determined. The data were correlated with age and with serum ferritin levels.
Although the patients were euthyroid clinically, the mean serum T3 and rT3 levels were significantly lower than the values in normal control children. Basal serum T4 and TSH values were similar to those of normal controls.
In thalassaemic children, during the TRH-test, the increases in serum TSH at 20, 30, and 45 min, the peak and the maximum ΔTSH were higher than those normally found.
Basal T3 and the 60 min value during the TRH-test were lower than normal, and the peak was delayed to 120 min. No statistically significant correlation was found between the hormonal parameters studied, and either chronological age or serum ferritin levels.
That there is a slight impairment of thyroid secretion in thalassaemia major children is suggested only by the differences in response during the TRH-test (peak and maximum ΔTSH is increased, T3 increase delayed, the negative linear correlation between basal TSH values and per cent increase in T3 and maximum ΔT3, and the positive linear correlation between per cent increase in TSH and in T3).
The low basal T3 and rT3 values might be explained by a decrease in the monodeiodinating enzymatic systems for T4, although other interpretations, e.g., increased clearance of T3 and rT3, cannot be excluded. The absence of clinical signs of hypothyroidism in thalassaemia major children might be due to the normal circulating levels of T4 if we accept that T4 has hormonal activity at least when T3 is low.
Thyroid hormone regulation of the catecholamine effects in human adipose tissue
Authors: Arner Peter , Wennlund Anders , Östman Jan 
Published: December 2008

Abstract.
The possibility of a relationship between the thyroid hormone level and the peripheral action of catecholamines was examined in 4 normal-weight and 19 obese euthyroid subjects as well as in 27 hyperthyroid subjects by comparing the serum thyroid hormone level and the in vitro effect of catecholamines on lipolysis and cyclic AMP accumulation in adipose tissue incubated with and without isopropyl noradrenaline (ISNA) or noradrenaline (NA). ISNA- and NA-induced rates of lipolysis and cyclic AMP production were significantly correlated with free thyroxine index (r = 0.63–0.74) and with the serum triiodothyronine level (r = 0.83–0.87). The thyroid hormone level was neither correlated with basal rate of lipolysis nor with basal cyclic AMP production (r < 0.2). These results suggest that the magnitude of catecholamine-induced cyclic AMP production by peripheral cells may be regulated by the level of circulating thyroid hormones. The effect of thyroid hormones on lipolysis appears to be specifically linked to the action of catecholamines.
DNA synthesis and secretory activity in parathyroid adenomas
Authors: Lloyd H. M. , Jacobi J. M. , Willgoss D. , Kearney J. , Ward P. 
Published: December 2008

Abstract.
DNA synthesis was measured in vitro by incorporation of [3H]thymidine into DNA in 42 parathyroid chief cell adenomas immediately after surgical removal. The results ranged from 18 to 185 dpm/μg DNA and showed a positive correlation with pre-operative values for serum immunoreactive parathyroid hormone (r = + 0.47; P < 0.001) and plasma calcium (r = + 0.35; P < 0.05). There was no correlation between DNA synthesis and tumour weight or mean diameter of tumour cell nuclei. The results suggest that DNA synthesis and cell division in parathyroid adenomas are determined in part by the secretory activity of the tumour. DNA synthesis measured on one occasion is not necessarily an overall index of tumour growth.
Calcium and pancreatic β-cell function. 12. Modification of 45Ca fluxes by excess of K+
Authors: Andersson T. , Betsholtz C. , Hellman B. 
Published: December 2008

Abstract.
Glucose stimulation of insulin release is supposed to result from depolarization of the pancreatic β-cells with subsequent influx of Ca2+. Isolated islets from non-inbred ob/ob-mice were employed for elucidating whether the glucose effects on the β-cell handling of Ca2+ could be simulated by the depolarization evoked by excess of K+. Addition of 25 mm K+ was as effective as 20 mm glucose in stimulating the intracellular uptake of 45Ca. In both instances the additional amounts of incorporated 45Ca appeared in the mitochondria and the secretory granules. When analysing the washout pattern for 45Ca it was evident that the effects of raising K+ differed from those evoked by glucose. Whereas glucose inhibited 45Ca efflux during perifusion with Ca2+-deficient medium the addition of K+ resulted in a slight stimulation. Furthermore, the 45Ca incorporated in response to K+ was more readily mobilised.
Determinations of redox states in A2 and B-cell rich islet specimens from guinea pigs, using bioluminescence assay of NAD+ and NADH
Authors: Brolin S. E. , Ågren A. , Petersson B. 
Published: December 2008

Abstract.
The ability of the pancreatic islets to form ATP is often studied and this naturally draws attention to the oxidation of NADH in the respiratory chain. It is therefore essential to obtain data on nicotinamide-adenine dinucleotide phosphates in the islet cells. In order to provide such information the concentrations of NAD+ and NADH were determined in collagenase isolated B-and A2-cell rich pancreatic islets from normal and streptozotocin-injected guinea pigs. In this way new data about the physiology of the A2-cells were obtained. The measurements were performed either in islets freshly isolated or cultured after isolation. Application of recent improvements in bioluminescence assay made it possible to carry out a sufficient number of determinations for calculating total nucleotide concentrations and their redox states.
In both kinds of islet specimens the total nucleotide concentrations were significantly higher when the cells had been cultured for 7 days after isolation. After culture the redox state as reflected by the ratio [NAD+]/[NADH] reached high values in both the A2- and B-cell rich specimens which may signify a strong capacity for drawing energy from NADH in the oxidative phosphorylation. Low values were found soon after isolation, probably indicating a state of hypoxia. The ratio [NAD+]/ [NADH] appears to be a sensitive measure of the metabolic state of the cells. The two kinds of islet specimens diplayed remarkable similarities, but it remains to be clarified whether the B-cells can change their redox state faster than the A2-cells. The bioluminescence techniques should provide the analytical facilities required for further studies of this kind.
Effect of cyproterone acetate on pituitary-adrenocortical function in man
Authors: van Wayjen R. G. A. , van den Ende A. 
Published: December 2008

Abstract.
Recent literature (1973–1976) suggests suppression of pituitary-adrenal function in patients (eg with pubertas praecox) who are treated with cyproterone acetate in high doses for prolonged periods. Therefore we investigated in our metabolic ward the effects of administration of 200 mg cyproterone acetate per day during 20 days to 4 healthy male volunteers.
Baseline plasma cortisol and ACTH levels, repeated diurnal plasma cortisol and ACTH profiles and the results of tetracosactide (Synacthen) stimulation tests and single-dose metyrapone (Metopiron) tests proved to be comparable before, during and after treatment. Moreover, a slight gradual increase in urinary cortisol excretion during the observation period indicated that cyproterone acetate in the given dose during 20 days certainly does not reduce the pituitary-adrenal function of 4 healthy male volunteers.
Long-term administration (during 1 to 7 years) of the combination of cyproterone acetate and ethinyloestradiol did not suppress serum levels of cortisol, prolactin, thyroxine and TSH in 18 female patients with hirsutism and/or acne.
The prolactin response to thyrotrophin-releasing hormone is intact in the human male castrate
Authors: LeRoith Derek , Lie Yair , Caine Marco , Spitz Irving M. 
Published: December 2008

Abstract.
This study has evaluated the role of the testis in the modulation of Prl secretion in the male. Six elderly male castrates aged 58–69 years, who had undergone bilateral orchidectomy for prostatic carcinoma, were challenged with LRH (100 μg) and TRH (200 μg) administered together as a bolus. Their response was compared to 8 elderly males aged 65–75 years. One additional male aged 26 years, who had lost both his testes following a war injury was also challenged with bolus LRH and TRH; in addition, he was given LRH, TRH and the dopaminergic antagonist, metoclopramide (MET) sequentially at 30 min intervals. On a subsequent occasion, MET was given also. The responses in this young castrate were compared to 24 young males who received the sequential protocol and 12 who received a solitary bolus of MET. In the castrate subjects, gonadotrophins were markedly elevated, whereas testosterone and oestradiol levels were significantly decreased as compared to the controls. The castrate subjects also had exaggerated LH and FSH responses to LRH. In contrast, basal Prl levels and the responses to TRH in the castrates were similar to the controls. In addition, the young male castrate showed a normal Prl response to metoclopramide, when this was given alone, or 30 min after TRH. The intact Prl profile in the castrate subjects should be contrasted to the exaggerated Prl response to TRH which has been described in patients with primary testicular failure and elevated LH and FSH levels. These results indicate that the presence of the testis is obligatory for the exaggerated Prl response to TRH observed in patients with primary testicular failure.