bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the glucocorticoid-receptor blocking action of RU 38486 in cultured ACTH-secreting human pituitary tumour cells and normal rat pituitary cells
Authors: Lamberts S. W. J. , Bons E. G. , Uitterlinden P. 
Published: December 2008

Abstract. The glucocorticoid-receptor blocking actions of RU 38486, a new compound with anti-progesterone activity, have been investigated in cultured human ACTH-secreting pituitary tumour cells and normal rat pituitary cells.
Pre-incubation of human pituitary tumour cells for 24 h with RU 38486 (1 μm) did not influence basal or CRF-stimulated ACTH release. RU 38486 (100 nm–1 μm) significantly overcame or prevented the dexamethasone (100 nm–1 μm)-induced inhibition of CRF-stimulated ACTH release by the cultured tumour cells prepared from 2 patients with Cushing's disease. The tumour cells of a third patient were insensitive to CRF. Pre-incubation for 24 h with 1 μm RU 38486 facilitated CRF-stimulated ACTH release significantly.
Studies with cultured normal rat pituitary cells showed that the inhibiting effect of 24 h pre-incubation with 10 and 50 nm dexamethasone on CRF-stimulated ACTH release could be acutely (measured over 4 h) overruled in a dose-dependent way by RU 38486 (100 nm, 1 and 10 μ), while pre-incubation for 24 h of these cells with RU 38486 (100 nm and 1 μm) significantly attenuated the acute inhibiting effect of 1 μm dexamethasone on CRF-stimulated ACTH-release.
The results of these in vitro experiments are discussed against the background of the possible therapeutic use RU 38486 in patients with Cushing's syndrome in order to block the deleterious effects of high circulating cortisol concentrations.
Prolactin inhibits oestradiol-induced luteinizing hormone release at the pituitary level
Authors: Miyake Akira , Terakawa Naoki , Tasaka Keiichi , Shimizu Ikuya , Ohtsuka Shirou , Lee Jin-Woo , Aono Toshihiro 
Published: December 2008

Abstract. The direct action of prolactin (Prl) on pituitary LH secretion was studied by examining its effect on oestradiol (E2)-induced luteinizing hormone (LH) release from the rat pituitary in a perifusion system and determining the oestrogen receptor (ER) content of the pituitary in hyperprolactinaemic female rats. When the pituitary from rats in pro-oestrus was perifused with medium alone, 10−7 m E2 significantly (P < 0.05) increased the LH concentration in the effluent by 60–130% of the basal level, but in medium containing 1 μg/ml Prl it did not cause LH release. In hyperprolactinaemic rats produced by implanting 2 anterior pituitary glands under the kidney capsule, the ER content of the cytosol of the pituitary (53.2 ± 2.9 fmol/pituitary) was significantly increased (P < 0.05), but that of the nuclei (6.8 ± 0.2 fmol/pituitary) was significantly decreased (P < 0.05) compared with the contents in rats in pro-oestrus.
These data suggest that Prl has a direct suppressive effect on LH secretion from the pituitary in the rat, and that decreased translocation of ER into the nucleus might relate to impaired LH release by E2 from the pituitary of hyperprolactinaemic rats.
Hormonal regulation of ascorbic acid in the adrenal of the rat
Authors: Overbeek G. A. 
Published: December 2008

Abstract. Fifteen days after hypophysectomy of rats the concentrations of ascorbic acid (AA) in adrenals, liver, blood and urine are lower than in normal rats or in rats 1 day after hypophysectomy. Despite the low levels the percentage AA depletion after administration of ACTH and the subsequent repletion to the pre-ACTH level are normal.
Lack of corticosteroids is not the cause of the low AA levels, as shown by experiments in 15 days adrenalectomized rats and in rats treated with low doses of dexamethasone.
Fifteen days treatment with high doses of dexamethasone lowered the AA concentrations in adrenals, liver and blood. Treatment with long-acting ACTH maintained adrenal weight but not adrenal and blood AA. A high dose of ACTH lowered these levels. The administration of AA markedly increased the AA levels in blood, but did not normalize its concentration in the adrenals, not even when the size of the adrenals was maintained by treatment with long-acting ACTH. Growth hormone, in particular when administered together with long-acting ACTH, markedly raised the AA concentration in the adrenals but hardly affected the AA blood level. Rats with high blood levels of prolactin induced by pituitary grafts in the kidney also had clearly higher AA levels in adrenals, but not in blood.
These results indicate that, although acute AA release from the adrenal is caused by ACTH, AA uptake to a certain concentration is not controlled by the pituitary gland, and above this concentration is promoted by growth hormone and prolactin. In the liver AA release may also be caused by ACTH but the AA production is promoted by other as yet unidentified pituitary factors.
Beta receptors in peripheral mononuclear cells increase acutely during exercise
Authors: Burman Kenneth D. , Ferguson Earl W. , Djuh Yin-Ying , Wartofsky Leonard , Latham Keith 
Published: December 2008

Abstract. Five healthy adult well trained men (averaging 49 miles running per week) were exercised to exhaustion on a treadmill. Plasma epinephrine increased from 168 ± 37 pg/ml prior to exercise to 633 ± 155 pg/ml immediately after exercise (P < 0.025) and plasma norepinephrine increased from 1608 ± 345 to 8576 ± 1662 pg/ml (P < 0.025) in the two respective periods. Beta receptor density increased from 53 ± 18 fmol/mg protein before exercise, to 223 ± 63 fmol/mg (P < 0.05) protein immediately after exercise, and then decreased to 83 ± 27 fmol/mg protein 1 h later (P < 0.05 compared to postexercise). The mean Kd value prior to exercise of 1.5 ± 0.2 × 10−11 m was unchanged statistically throughout the study. Following correction for haemodilution, serum total and free T4 and T3 concentrations were also unchanged during exercise, although reverse T3 levels did increase from 39 ± 4 to 45 ± 0 ng/dl (P < 0.05).
These findings suggest that: 1) plasma epinephrine, norepinephrine and beta receptor density, but not Kd, increase acutely during exercise and 2) total and free
Decrease of LRH receptors in the pituitary gland in streptozotocin-induced diabetic rats
Authors: Tasaka Keiichi , Terakawa Naoki , Shimizu Ikuya , Ohtsuka Shirou , Miyake Akira , Aono Toshihiro 
Published: December 2008

Abstract. In studies into the mechanism of anovulation in the diabetic condition, the LRH receptor content of the pituitary gland of rats with diabetes mellitus was determined. Normal female rats weighing 180–200 g were injected iv with either streptozotocin (6 mg/100 g body weight) or vehicle in dioestrus of the oestrous cycle. The rats were sacrificed by decapitation 9 days after treatment, and serum LH concentrations and the LRH content of the medial basal hypothalamus (MBH) were measured by radioimmunoassay (RIA), and the LRH receptor content of the pituitary gland was determined.
The serum concentration of LH and the LRH content of the MBH in diabetic rats were 34.4 ± 4.8 ng/ml (mean ± sem) and 2.05 ± 0.04 ng/MBH, respectively, which were similar to the respective values of normal rats in dioestrus. However, the LRH receptor content of diabetic rats (13.2 ± 3.9 fmol/pituitary) was significantly (P < 0.05) lower than that of normal rats in dioestrus (68.0 ± 7.1 fmol/pituitary) and pro-oestrus (59.4 ± 13.6 fmol/pituitary).
These results suggest that anovulation in diabetic rats is at least partly attributable to a low content of LRH receptors in the pituitary gland.
Post-natal thyroid function in low birth weight infants; a longitudinal assessment of free thyroxine and thyroid hormone binding globulin
Authors: Hirano Takeki , Singh Jaideep , Srinivasan Gopal , Pildes Rosita 
Published: December 2008

Abstract. Because the concentrations of serum free thyroxine (FT4) and thyroid hormone binding globulin (TBG) have not been fully evaluated in preterm infants at the immediate post-natal period, we studied the longitudinal changes of serum FT4 and TBG, along with thyroxine (T4) and thyroid stimulating hormone (TSH), at birth (cord blood), 2 days, 1 week and 2 weeks of age in 7 infants with birth body weight ≦ 1000 g, 7 infants with body weight 1001 to 1350 g, 11 infants with body weight 1351 to 2499 g, and 11 full-term infants. Free T4 concentrations were measured by Corning Medical radio-immunoassay (RIA) kit.
The infants with extremely low birth weight (ELBW) (body weight ≦ 1000 g) showed precipitous declines of total T4 and, to a lesser extent, of FT4 concentrations at 1 and 2 weeks of age. These post-natal T4 and FT4 decreases in ELBW neonates have not previously been reported. The clinical significance of this finding remains, speculative, but it may be due to metabolic or nutritional problems related to extreme prematurity itself.
This study suggests that measurement of FT4 is a useful adjunct to the assessment of ELBW infants with wery low T4 values, if done between 1 to 2 weeks af age, and could be used as a primary hypothyroid screening tool instead of T4 measurements, provided that an FT4 assay is developed that uses the elute of blood spotted on filter paper.
Serotonergic regulation of prolactin and growth hormone secretion in man
Authors: Lewis David A. , Sherman Barry M. 
Published: December 2008

Abstract. Controversy still exists regarding the role of serotonin in the regulation of prolactin (Prl) and growth hormone (GH) secretion in man. We gave healthy male volunteers three oral doses (0.5, 1.0 and 1.5 mg/kg) of fenfluramine, a serotonin-releasing agent and uptake inhibitor, and a corresponding placebo. There was a significant dose-response effect of fenfluramine on Prl but not on GH levels. Following the highest dose of fenfluramine, mean Prl levels increased from 9.7 ng/ml to 42.3 ng/ml.
In a separate study, subjects were pre-treated with cyproheptadine, a serotonin antagonist, before the administration of fenfluramine. Cyprohaptadine did not significantly affect basal Prl or GH levels, but it did blunt the response of Prl to fenfluramine. Cyproheptadine pretreatment did not alter plasma levels of fenfluramine.
Our findings support a stimulatory role for serotonin in the regulation of Prl secretion in man. They also suggest that serotonin does not have a major influence on GH secretion in man.
Cyclic Cushing's syndrome combined with cortisol suppressible, dexamethasone non-suppressible ACTH secretion: a new variant of Cushing's syndrome
Authors: Schweikert Hans-Udo , Fehm Horst Lorenz , Fahlbusch Rudolf , Martin Rainer , Kolloch Rainer , Higuchi Miyoko , Krück Friedrich 
Published: December 2008

Abstract. A 55 year old woman with an unusual form of Cushing's disease was studied. During several periods (periods lasting up to 84 days) evidence of cortisol hypersecretion with cycles occurring every 6 days was found. Suppression of plasma cortisol through orally administered dexamethasone (up to 32 mg per day) could not be achieved either during periods of cyclic cortisol hypersecretion or during apparent remission with normal cortisol secretion. Marked suppression of plasma ACTH was measured in response to an iv infusion of 50 mg cortisol over a period of 55 min whereas a similar test with 2 mg dexamethasone (iv bolus) did not suppress ACTH secretion. Transsphenoidal exploration of the sella revealed a tumour surrounding the anterior pituitary. Examination of the pituitary showed a few tiny tumour structures embedded in normal tissue which could not be removed, when the tumour was resected selectively under preservation of normal appearing tissue. Post-operatively, clinical and chemical remission (normal response to 1 mg dexamethasone) was observed for about 4 months. Thereafter, cortisol hypersecretion occurred again necessitating bilateral adrenalectomy.
Our results are compatible with the assumption that normal hypothalamic-pituitary-adrenal suppressibility with cortisol, but not with dexamethasone, was caused by the loss of feedback receptors for dexamethasone in the presence of cortisol receptors in the cells which secrete ACTH or CRF.
The combination of cyclic hypercortisolism with dexamethasone non-suppressible Cushing's syndrome has not been reported before and thus represents a new variant of Cushing's syndrome.
Contribution to the aetiology of diabetes insipidus: Yersinia pseudotuberculosis infection
Authors: Massol J. , Humbert Ph. , Semon C. , Fellmann D. 
Published: December 2008

Abstract. A case concerning a young man presenting with polyuria and polydipsia which were preceded 1 month earlier by a febrile enteritis is reported.
The role of Yersinia pseudotuberculosis in diabetes insipidus of this type is discussed on the basis of clinical, biological and evolutional criteria.
Plasma free and total iodothyronine levels in hypophysectomized and intact lamb foetuses during the last third of gestation
Authors: Wrutniak Chantal , Cabello Gérard , Bosc Michel 
Published: December 2008

Abstract. The changes in plasma levels of thyroxine (T4), free thyroxine (free T4), triiodothyronine (T3), free triiodothyronine (free T3), and reverse triiodothyronine (rT3) were observed in intact or hypophysectomized lamb foetuses during the last third of gestation. Hypophysectomy was performed at two stages: 100 and 120 days of gestation. Cord blood was collected after Caesarean section.
In intact foetuses, T4 and free T4 levels increased significantly between day 100 and 120 of gestation, but decreased from day 132 to birth. T3 levels, low until day 132, rose abruptly during the last 12 days of gestation, as did the T3/free T4 ratio. Free T3 levels, relatively high on day 100, decreased until day 130 to rise during the last days of gestation. Reverse T3 levels, high since day 100, increased sharply until day 132 as did the reverse T3/free T4 ratio, and then declined. In hypophysectomized foetuses, undetectable or very low levels of T4, free T4 and rT3 were observed on day 120 and 144. T3 levels, although decreased by pituitary destruction, remained at 39.7% (120 days) and 21.4% (144 days) of the values recorded in intact foetuses. Free T3 levels, normally depressed at the end of gestation, were not affected by hypophysectomy on day 120. When hypophysectomy was performed later, the levels of T4, free T4 and rT3 were slightly increased on day 144 as compared with those of the other hypophysectomized foetuses.
This study confirms the changes in the plasma iodothyronine levels observed previously in the lamb foetus. Moreover, it appears that T4 thyroid secretion depends almost exclusively on foetal pituitary function, and that if the sheep placenta is impermeable to T4 and rT3, a significant transfer of maternal T3 can occur.
Effect of gonadotrophins on progesterone secretion by cultured granulosa cells obtained from human preovulatory follicles
Authors: Hillensjö T. , Sjögren A. , Strander B. , Nilsson L. , Wikland M. , Hamberger L. , Roos P. 
Published: December 2008

Abstract. Granulosa cells were obtained from human preovulatory follicles in 31 women undergoing in vitro fertilization and embryo transfer due to tubal infertility. Follicular maturation was stimulated and synchronized by treatment with Clomiphene or human menopausal gonadotrophin (hMG), or both, plus human chorionic gonadotrophin (hCG). Follicles were aspirated by ultrasound guided puncture approximately 34–36 h after the hCG injection.
The granulosa cells were washed and suspended in modified medium 199 containing 10% foetal bovine serum and cultured as monolayers for 6–8 days in the absence and presence of hormones and reactants. Progesterone formation was analyzed by RIA. In general, the cells underwent morphological luteinization and secreted high amount of progesterone. Under basal conditions the secretion of progesterone was highest during the first 2 days in culture and then gradually declined. Progesterone secretion was stimulated by human LH, hCG and the adenylate cyclase stimulator forskolin, with a maximal effect between days 2–6. The β-adrenergic agonist isoproteronol in preliminary experiments potentiated the stimulatory effect of hCG but had no own stimulatory effect. No clear differences in progesterone secretion or responsiveness to in vitro stimulation relating to the various in vivo stimulation protocols were found.
Reproductive endocrine effects of intranasal administration of progesterone to adult female rhesus monkeys
Authors: David G. F. X. , Puri V. , Dubey A. K. , Puri C. P. , Kumar T. C. Anand 
Published: December 2008

Abstract. Adult female rhesus monkeys exhibiting normal ovulatory menstrual cycles were treated with progesterone nasal sprays. Animals in group A (n = 9) were treated with the solvent only (controls). Animals in groups B (n = 6), C (n = 17) and D (n = 7), respectively, were treated with a daily dose of 0.4, 2 and 10 μg of progesterone and the spraying was done between days 5–14 of the cycle. Ovulation was monitored by laparoscopy on day 20. The serum endocrine profile throughout the treated menstrual cycle was studied with respect to oestradiol and progesterone. Bioactive luteinizing hormone (bLH) was studied in blood samples taken on the day of the mid-cycle oestradiol peak, 2 days before, and 2 days after. The menstrual cycle was divided into two phases with respect to the mid-cycle oestradiol peak: phase I was taken to include day 1 of the cycle to the day of the oestradiol peak, and the remaining part of the menstrual cycle was considered to be phase II.
The serum-endocrine profile in the controls was similar to that observed in normal ovulatory menstrual cycles. However, in the progesterone-treated groups three types of menstrual cycles were discernable on the basis of the serum endocrine profile. In the type I menstrual cycle, observed only in group C (n = 10), the mid-cycle bLH peak was abolished and the progesterone levels remained low throughout the cycle. Laparoscopy revealed these to be anovulatory cycles. In the type II menstrual cycle, seen in the 3 animals of group B, 2 animals of group C, and in all the 7 animals of group D, the mid-cycle bLH peak was abolished and the progesterone levels during phase II of the cycle were significantly lower than in the controls, indicative of poor luteal function. In the type III menstrual cycle seen in the remaining monkeys, the serum endocrine profile did not differ from that seen in the controls. Thus, the present studies indicate that the intranasal administration of progesterone shows a dose-response effect with respect to the suppression of the oestradiol induced mid-cycle surge of bLH. Suppression of the mid-cycle bLH peak resulted in anovulatory cycles or ovulatory cycles with poor luteal function.
Effect of prolonged dopamine receptor blockade on lactotroph activity in the rat pituitary gland
Authors: Prysor-Jones R. A. , Silverlight J.J. , Jenkins J. S. 
Published: December 2008

Abstract. The dopamine antagonist fluphenazine was administered to young rats in the presence or absence of physiological concentrations of oestradiol for periods of 230 days.
An important observation arising from the investigation was that no pituitary tumours were produced by the combination of prolonged dopamine receptor blockade and small amounts of oestradiol.
Prolactin (Prl) secretion increased rapidly with fluphenazine but in the absence of oestrogen lactotroph activity subsequently declined after 20 days and this decrease in hormone secretion was accompanied by a greatly increased dopamine turnover in the medio-basal hypothalamus. In contrast, small amounts of oestradiol modified the effect of fluphenazine alone causing a greatly increased secretion of Prl for a much larger period and a reduction in the dopamine content of the hypothalamus. This combination also doubled the synthesis of DNA by the pituitary compared with controls, and electron microscopy revealed evidence of increased secretory activity of the lactotrophs in the presence of both fluphenazine and oestrogen but not in those animals treated with fluphenazine only.
Towards the end of the experiment Prl values declined even in the presence of oestrogen and increasing the dose of fluphenazine had no significant effect. It was suggested that eventually there may be a direct inhibitory action of the dopamine antagonist on the lactotrophs.
How to deal with undetectable and low measurable serum thyroglobulin levels in the follow-up of patients with differentiated thyroid carcinoma?
Authors: Välimäki Matti , Lamberg Bror-Axel 
Published: December 2008

Abstract. Serum thyroglobulin (Tg) was measured in 52 patients 3 months to 15 years (mean 5.3 years) after thyroidectomy with or without subsequent radioablation for differentiated thyroid carcinoma, before and after the interruption of suppressive thyroxine (T4) replacement therapy for 5 weeks. Whole body scintigraphy was carried out at the end of the T4 withdrawal period.
Serum Tg was undetectable (< 3 μg/l) in 38 patients on T4 therapy, in 18 the scintigraphy showed a minimal accumulation in the neck region and in 20 no uptake anywhere after withdrawal of T4. In the former group Tg rose in 10 patients to 4–21 μg/l when off T4 which seemed to correspond to the normal tissue left in situ, in the latter group Tg rose only in 2 patients to 5 and 21 μg/l, respectively. Two patients out of 14 with detectable Tg on T4 had pulmonary metastases as uncovered by whole body scintigraphy (in one of them Tg rose from 12 μg/l on T4 to 1200 μg/l off T4) and 6 patients were suspected for having recidual cancer tissue (2 patients had a negative scintigraphy) because the Tg rose (66– 215 μg/l) over the upper limit of the reference range (< 50 μg/l) after T4 withdrawal.
In conclusion, in the follow-up of patients with differentiated thyroid carcinoma no routine scans are needed as long as serum Tg remains undetectable but further examinations are shortly warranted when detectable Tg is obtained during T4 suppression.
Treatment of severe Graves' ophthalmopathy with cyclosporin A
Authors: Utech C. , Wulle K. G. , Bieler E. U. , Pfannenstiel P. , Panitz N. , Kiefer H. 
Published: December 2008

Abstract. Ten patients with severe Graves' ophthalmopathy, resistant to other therapeutic regimens were treated with cyclosporin A (CyA) over a period of 6 months. Clinically, 9 patients improved, 2 of them only after addition of corticosteroids. Intra-ocular tension on upward gaze decreased in all of these 9 patients (P < 0.01). In 6 patients there was a significant decrease in eye muscle thickness under the treatment (P < 0.05) as determined by computerized tomography.
Side effects (e.g., paraesthesia, proteinuria) which were observed under higher doses of CyA, disappeared after lowering the dose. In only one out of 3 patients with hypertension an antihypertensive medication became necessary.
CyA appears to be a valuable drug for treatment of severe Graves' ophthalmopathy when previous therapeutic regimens turned out to be unsuccessful.