bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radioimmunoassay detection of endorphins from long-term culture of human pituitary tumour cells
Authors: Sharp Burt , Melmed Shlomo , Goldberg Ronald , Carlson Harold E. , Refetoff Samuel , Hershman Jerome M. 
Published: December 2008

Abstract.
Using a sensitive and precise radioimmunoassay for human β-endorphin, we have demonstrated the sustained secretion of opioid peptides from human pituitary tumour cells. Pituitary tumour tissue obtained from a patient with Nelson's syndrome was maintained in continuous monolayer culture and secreted both β-lipotropin and β-endorphin, with predominance of the latter. This is compatible with the idea that the β-endorphin in normal human serum is secreted as such despite the predominance of β-lipotropin compared with β-endorphin in the anterior pituitary.
Influence of blood removal under ether anaesthesia on the release of prolactin during the oestrous cycle in the rat. Involvement of the ovaries
Authors: Boehm Nelly , Plas-Roser Salomé , Lazarus Christine , Aron Claude 
Published: December 2008

Abstract.
The aim of this work was to study the stresslike effects of blood removal unter ether anaesthesia at different stages of the di-oestrus period in 4-day cyclic female rats. Blood removal by heart puncture or laparotomy and bleeding from the abdominal vena cava both under ether anaesthesia were shown to precipitously evoke prolactin release on di-oestrus I morning and on di-oestrus II afternoon. Adrenalectomy did not prevent this effect from occurring on di-oestrus I morning following either procedure of blood removal. Ovariectomy completely suppressed the stress-like effects of ether anaesthesia whereas progesterone appeared capable of restoring prolactin release under these circumstances. No prolactin positive response to ether anaesthesia was observed on di-oestrus II morning, in unoperated controln females.
Release of LH in vitro from anterior pituitary glands of ovariectomized rats by LRH or elevated potassium concentration after pre-treatment with oestradiol benzoate in vivo
Authors: Tijssen A. M. I. , de Koning J. , van Rees G. P. 
Published: December 2008

Abstract.
Pituitary glands from ovariectomized rats which had been pre-treated with oestradiol benzoate (OeB) or solvent oil were incubated in Krebs-Ringer bicarbonate buffer with glucose containing either LRH (1000 ng/ml) or a high K+ concentration (50 mM). OeB (7 μg sc) or oil was injected at 2.5 or 6.5 h before the beginning of the incubation experiment or during the three preceding days (three daily injections). Depending upon the period during which the pituitary glands had been exposed to OeB LH release induced by LRH was inhibited (negative effect of OeB) or augmented (positive effect). When the glands were incubated in medium containing high K+, only the negative effect of OeB pre-treatment was seen. It is concluded that that part of LRH-induced LH release which is mimicked by high K+ is involved in the negative effect of OeB, but not in its positive effect.
Susceptibility to proteolysis of thyroglobulin from rats and guinea-pigs treated with excess iodide
Authors: Sinadinović J. , Krainčanič M. , Marinković B. , Jovanović M. , Petrović N. , Liewendahl K. 
Published: December 2008

Abstract.
The effect of excess iodide on proteolysis of in vivo 125I-labelled thyroglobulin (Tg) from rats and guinea-pigs was investigated in vitro using preparations of thyroid lysosomes and exogenous proteases (Pronase). Lysosomes were obtained by centrifugation of pig thyroid homogenates. This lysosomal preparation induced maximal proteolysis of Tg at pH 3.6 to 4.6 and was stimulated by KCl. Treatment of rats with excess iodide for up to 28 days had no effect on the proteolysis of Tg by lysosomes or Pronase. Decreased resistance of Tg to proteolysis by lysosomes and pronase was observed in guinea-pigs treated with excess iodide for 3 days, whereas Tg from guinea-pigs treated for longer time periods had increased resistance to proteolysis. This difference in the susceptibility to proteolysis of Tg provides an explanation why long-term administration of excess iodide is goitrogenic in guinea-pigs but not in rats.
Circulating immune complexes in diabetics with severe microangiopathy: evaluation by two different methods
Authors: Andreani Domenico , Mario Umberto Di , Galfo Clara , Ventriglia Luigi , lavicoli Mario 
Published: December 2008

Abstract.
An investigation on circulating immune complexes (AgAb) was carried out in 80 diabetics with severe microangiopathy and in 71 diabetics without microvascular lesions.
The duration of the disease, the type of diabetes, the type of treatment and the main localization of microangiopathy (retinopathy and nephropathy) were taken into account. AgAb were detected by two different methods: the solid phase Clq binding test (ClqSP) and the conglutinin binding test (KgBt).
AgAb detected by ClqSP were increased both in prevalence and quantities in diabetics with severe microangiopathy regardless of the duration of the disease and the type of diabetes. Long standing diabetics without microangiopathy had similar prevalence of AgAb as normal controls. The presence of AgAb was not in correlation with the type of treatment and was similar in diabetics with retinopathy and in those with nephropathy. When AgAb were detected by KgBt, they were found with higher prevalence in diabetics than in normal controls but no correlation with microangiopathy was observed. AgAb, detected by KgBt, were higher in long standing type I diabetics.
Since the two methods detect different AgAb it is concluded that AgAb present in diabetics seem to be heterogenous and part of them are related to the presence of microangiopathy.
The effect of ACTH stimulation on plasma steroids in two patients with congenital hypoaldosteronism and in their relatives
Authors: Drop S. L. S. , Frohn-Mulder I. M. E. , Visser H. K. A. , Sippell W. G. , Dörr H. G. , Schöneshöfer M. 
Published: December 2008

Abstract.
In two children with isolated congential hyperreninaemic hypoaldosteronism, as well as in their relatives, plasma levels of aldosterone (Aldo), corticosterone (B), deoxycorticosterone (DOC), 18-OH-B and 18-OH-DOC were measured before and after an iv bolus of 0.25 mg Synacthen® (Ciba). A corticosterone methyl oxidase deficiency type II was demonstrated in one child. Her normoreninaemic parents (no consanguinity) had plasma values consistent with heterozygosity. The results in the other child and one asymptomatic sib were compatible with a partial corticosterone methyl oxidase deficiency type I. His parents were consanguine but had normal Aldo levels. Overnight dexamethasone administration did not suppress any of the steroids measured except cortisol, suggesting synthesis of these steroids by the zona glomerulosa.
Effects of ACTH on the zona glomerulosa of sodium-loaded timolol maleate-treated rats: stereology and plasma hormone concentrations
Authors: Nussdorfer Gastone G. , Neri Giulano , Belloni Anna S. , Mazzocchi Giuseppina , Rebuffat Piera , Robba Claudia 
Published: December 2008

Abstract.
The effect of chronic ACTH administration on the growth and aldosterone secretion of the zona glomerulosa of sodium-loaded timolol maleate-treated rats was investigated by stereological and radioimmunological techniques. Combined sodium loading and timolol maleate administration induced a significant atrophy of the zona glomerulosa and its cells. The plasma concentration of aldosterone was significantly decreased, while that of corticosterone did not vary. ACTH administration completely reversed zona glomerulosa atrophy, and the plasma concentration of corticosterone was noticeably enhanced, whereas that of aldosterone underwent a further decrease. This data suggests that in the absence of the other adrenoglomerulotrophic factors, ACTH stimulates the growth of the zona glomerulosa, but transforms its parenchymal elements to a functional fasciculata cell type.
Influence of mesonephros on foetal and neonatal rabbit gonads I. Sex-steroid release by the testis in vitro
Authors: Grinsted J. , Byskov A. G. , Christensen I. J. , Jensenius J. C. 
Published: December 2008

Abstract.
The experiments were performed to study the influence of mesonephros on gonadal sex hormone release. Foetal and neonatal rabbit testes were cultured for 5 days, with and without their mesonephric tissue. The culture media were harvested every day and analyzed by RIA for the content of testosterone, progesterone and oestradiol. The development of the tissues were evaluated microscopically after culturing.
The results show that between day 20 pc and day 1 pp the mesonephric tissue lowered the amounts of testosterone in co-cultures with testis. This effect disappears when the mesonephric derived cells develop the capacity to synthesize a meiosis inducing substance (MIS). A relationship between decrease of testosterone and secretion of MIS is discussed.
It is concluded that the steroid producing cells of the testis, the Leydig cells, originate or are heavily influenced by mesonephros during early testicular organogenesis.
Influence of mesonephros on foetal and neonatal rabbit gonads
Authors: Grinsted J. 
Published: December 2008

Abstract.
To test whether the mesonephros influences the steroid hormone release by the foetal and neonatal ovary, rabbit ovaries were cultured with and without the mesonephros for a period of 5 days. The media were harvested once every day and analyzed by RIA for the content of testosterone, oestradiol and progesterone.
Mesonephros produced progesterone only at day 20 pc. At day 21 and 28 pc significant amounts of all three hormones were produced.
The media of the co-cultures of ovaries with the mesonephros contained on day 23 and 28 pc less testosterone. On day 23 pc less and on day 3 pp more oestradiol was found in the media of the co-cultures. At day 21 pc progesterone release was increased by the mesonephros.
It could be concluded that the mesonephros is able to synthetize steroids and possesses the capacity both to lower and to increase ovarian steroid release in culture. The enhancement of ovarian steroid synthesis in co-cultures with the mesonephros at certain ages might be due either to increased substrate production and/or increased enzymatic activity. The lowering of steroids seen at different ages might be due to mesonephric steroid binding. The mesonephros appeared to influence the male and female rabbits differently at the same ages.
The role of sex hormones in the mechanism of inhibited LH release in female patients with anorexia nervosa
Authors: Baranowska B. , Zgliczyński S. 
Published: December 2008

Abstract.
In order to elucidate the mechanism of impaired LH secretion, 60 female patients with anorexia nervosa were investigated. A control group consisted of 14 women of the same age, examined in the follicular phase of the menstrual cycle. The serum LH, FSH, prolactin, TSH, testosterone, dihydrotestosterone, dehydroepiandrosterone, Δ 4-androstenedione, oestrone, oestradiol, oestriol, progesterone, thyroxine, triiodothyronine, reverse T3 and serum sex hormone binding globulin (SHBG) concentrations were measured. The results showed a significant increase in serum dehydroepiandrosterone, testosterone, oestriol and reverse T3 concentrations. However, oestrone, oestradiol, progesterone, SHBG and triiodothyronine levels were significantly lower than those of the control group. The mean serum LH concentration in patients with anorexia nervosa before and after LRH stimulation was significantly lower than that in the control group, but FSH secretion in response to LRH was normal. All hormonal changes in anorexia nervosa disappeared after weight gain during cyproheptadine treatment.
Dramatically increased dehydroepiandrosterone levels suggest that the high testosterone in women with anorexia nervosa is derived from adrenal rather than from gonadal steroids.
There was no correlation between serum testosterone, dehydroepiandrosterone, oestriol and LH concentrations indicating that steroid hormone disturbances do not cause impaired LH release in anorexia nervosa.
Acute suppressive effect of ACTH-induced cortisol secretion on serum prolactin levels in healthy man
Authors: Bratusch-Marrain P. , Vierhapper H. , Waldhäusl W. , Nowotny P. 
Published: December 2008

Abstract.
The effect of ACTH on serum prolactin concentrations was studied in 6 healthy women in the follicular phase of the menstrual cycle, in 5 healthy men and in 6 patients (5 males, 1 female) with adrenocortical insufficiency. In healthy women prolactin levels decreased from basal, 14.4 ± 2.1 (SEM) μg/l to 9.4 ± 0.9 μg/l after 30 min and to 8.1 ± 0.7 μg/l after 60 min of iv administration of synthetic ACTH1-24 (0.25 mg). Upon continuous infusion of ACTH1-24 (0.25 mg for 8 h) prolactin fell to 4.4 ± 0.6 μg/l in healthy women and to 4.6 ± 1.5 μg/l (basal: 10.6 ± 1.8 μg/l) in healthy men. In patients with adrenocortical insufficiency prolactin concentrations remained unchanged following an 8 h infusion of ACTH1-24 (before ACTH: 14.5 ± 2.3 μg/l, after ACTH: 16.3 ± 3.1 μg/l). After treatment with dexamethasone (2 mg/day for 3 days) however, prolactin concentrations were suppressed both in healthy women (−52 ± 7%) and men (−25 ± 11%) and in patients with adrenocortical insufficiency (−21 ± 10%). Thus the effect of ACTH on prolactin appeared to be mediated via enhanced cortisol secretion. It is suggested that an acute increase in cortisol levels within the physiological range may modulate prolactin secretion.
Inhibition of thyroidal iodine release by oestrogens in euthyroid subjects
Authors: Zaninovich Angel A. , Boado Rubén , Ulloa Edgardo , Bromage Niall R. , Matty A. J. 
Published: December 2008

Abstract.
The effects of oestrogens on the release of thyroxine iodide (T4 I) and non-T4 I by the thyroid gland of 6 normal subjects and 3 thyrotrophin (TSH)-treated patients with hypopituitarism were assessed before, during and after treatment with 25 mg of Dienoestrol (Glaxo Lab.), orally, daily, during 8 days. Each subject received an iv injection of 150 μCi of 125I followed 6 days later by an iv injection of 75 μCi of [131I]T4. Blood samples and collections of urine were obtained every 12 h. From plasma and urinary (U) radioactivity, the ratio U[125I]/ U[131I], U[125I]/PB[125I] and U[131I]/PB[131I] were obtained and served to calculate thyroidal iodine release and non-T4 I secretion by the thyroid gland. T4 I secretion was equivalent to T4 I disposal rate obtained by the semilogarithmic regression line of PB[131I]. In normal subjects, oestrogens decreased T4 I secretion from 491 ± 57 (sd) nmol/day to 451 ± 60 nmol (P < 0.025), while in the same subjects serum TSH increased with oestrogens from 3.3 ± 1.1 to 6.6 ± 2.1 mU/l (P < 0.01). The non-T4 I secretion had a mean of 585 ± 307 nmol/day during control, 324 ± 199 nmol during oestrogens (P < 0.01) and 480 ± 286 nmol after oestrogens (P < 0.05 vs oestrogens). In the TSH-treated patients oestrogens induced non-significant reductions in T4 I and non-T4 I secretion, although total iodine secretion decreased significantly (P < 0.05). The data is consonant with a partial inhibition by oestrogens of thyroid gland release.
Elevated serum thyroxine-binding globulin by X-chromosome transmission
Authors: Penhaligon J. , Wellby M. L. 
Published: December 2008

Abstract.
A kindred with a high prevalence of hereditary serum thyroxine-binding globulin (TBG) is described. Seventeen of the 29 members of the kindred have the increased TBG trait as demonstrated by a combination of increased serum total thyroxine (T4) and total triiodothyronine (T3) and decreased T3 resin uptake. In 12 of the 17, the anomaly was confirmed by measuring serum TBG activity as maximum binding capacity of T4. The pattern of increased TBG is consistent with X-linked inheritance. One of the affected members had proven thyrotoxicosis and two others were subjected to sub-total thyroidectomy.
Effects of ethanol and other organic solvents on the kinetic behaviour of purified human placental oestradiol-17β-dehydrogenase
Authors: Lübbert H. 
Published: December 2008

Abstract.
The effects of acetone, ethanol, dimethylsulphoxide, glycerol, and propanediol on the formation of reduced coenzyme in the presence of purified human placental oestradiol dehydrogenase were measured fluorometrically at 10 μm oestradiol-17β and 500 μm NAD. Addition of increasing amounts of each solvent except glycerol resulted in an initial increase followed by a decline in rate of the enzyme catalyzed reaction. Glycerol caused a linear decline in rate.
A range (0.1–25%, v/v) of ethanol concentrations was tested for its effect upon the Km and Vmax values for oestradiol, NAD, and NADP. Over this range the Km value for NADP remained nearly constant (0.6–0.8 μm). The Km value for NAD increased rapidly with an upward convex shape of the curve (6.6–25 μm), and the Km value for oestradiol with NAD or NADP as cofactor increased slowly with an upward concave shape (6.7–25 μm). With increasing ethanol concentration, the maximum velocity increased, reaching its highest values at 10 and 20% ethanol for NAD and NADP, respectively, and then declined. At the maximum, Vmax values for NAD and NADP were, respectively, 165 and 200% the values obtained with 0.1% ethanol.
Failure of dexamethasone and ACTH to suppress plasma testosterone in cryptorchid boys
Authors: Facchinetti F. , Bracci R. , Vanni M. G. , Genazzani A. R. 
Published: December 2008

Abstract.
Cryptorchid boys show evident alterations in the fine structure of the testes, although they respond in a normal manner to various tests of endocrine function. On the other hand, there is evidence that glucocorticoids suppress plasma testosterone levels, although the mechanism is unknown. Eight control subjects and 8 bilaterally cryptorchid boys, at Pl stage of sexual maturation, were therefore studied by determining the degree of testosterone suppression induced by glucocorticoids. The subjects were submitted to a short dexamethasone (DXM) suppression (1.5 + 0.5 mg at 20.00 and 24.00 h, respectively) and to a short iv ACTH stimulation (1 U/m2 body surface). Basal concentrations of cortisol, androstenedione and testosterone were similar in both groups. Cortisol and androstenedione responded to both DXM suppression and ACTH stimulation in an identical manner in the two groups. DXM lowered the basal levels of testosterone by 46.4 ± 5.8% (mean ± se) in the controls, but only by 6.9 ± 6.6% in the cryptorchid boys (P < 0.001). ACTH only induced a significant decrease in the controls (from 110.9 ± 18.5 to 61.4 ± 10.9 and 72.3 ± 11.8 pg/ml (P < 0.025), after respectively 20 and 30 min), while no significant differences were found in the cryptorchid subjects.
These data indicate that in bilateral cryptorchidism, plasma T is not affected by exogenous (DXM) or endogenous (cortisol) glucocorticoids.
Control of testicular steroidogenesis in foetal rat: effect of decapitation on testosterone and plasma luteinizing hormone-like activity
Authors: Habert R. , Picon R. 
Published: December 2008

Abstract.
These studies were designed to investigate the regulation of testicular testosterone and the role of the hypophysis during the last 5 days of gestation in the rat. Plasma LH-like activity was measured by bioassay and testosterone by radioimmunoassay. In both sexes, plasma LH-like activity levels were low on days 17.5 and 18.5 (< 0.10–0.26 ng/ml) and rose on day 19.5 (0.10–1.25 ng/ml). Thereafter the levels increased considerably and were significantly higher in females than in males: on day 21.5 they reached 0.44–2.42 ng/ml in males and 2.20–3.96 ng/ml in females. Plasma levels of testosterone were significantly higher in males than in females and were maximal on day 18.5 in males. Testicular content of testosterone reached maximum values on day 18.5 and remained constant thereafter. Foetal decapitation clearly reduced testicular production of testosterone and plasma LH-like activity only after day 19.5. A residual gonadotrophic activity was detected at all stages in decapitated foetuses from both sexes (< 0.10–0.46 ng/ml). These results suggest that pituitary LH secretion and pituitary-testicular interrelationships are essentially established between day 19.5 and 20.5, and that the ageing testis becomes more dependent on gonadotrophic stimulation. The existence of an extrapituitary LH-like activity might indicate the presence of placental gonadotrophins.
Serum levels of prolactin, TSH and gonadotrophins following LRH/TRH - double stimulation tests during the menstrual cycle
Authors: Baumgarten S. , Römmler A. , Post K.G. , Hammerstein J. 
Published: December 2008

Abstract.
The objective of this study was to re-investigate the capacity of pituitary prolactin (Prl) and thyrotrophin (TSH) secretion throughout the normal menstrual cycle to respond to repeated thyrotrophin releasing hormone (TRH) stimulation analogous to the double luteinizing hormone-releasing hormone (LRH) stimulation test. This test has been shown to be a sensitive parameter for oestrogenic effects on the gonadotrophs. In addition, the volunteers were selected carefully on the basis of ovulatory cycles and otherwise normal endocrine function.
In 9 women a combined LRH/TRH double stimulation test was performed during the early follicular, periovulatory and mid-luteal phases. TRH (200 μg) and LRH (25 μg) each were given iv twice, 2 h apart.
Basal and LRH stimulated luteinizing hormone (LH) and follicle stimulating hormone (FSH) were found to follow characteristic cyclic response patterns. The LH responses after both LRH stimulations were greatest in the periovulatory phase; Δ1 and Δ2 were higher in the mid-luteal phase than in the follicular phase. Maximum FSH response to LRH was found during the periovulatory phase, but the FSH response in the early follicular phase was greater than that found in the mid-luteal phase. In contrast, basal and TRH stimulated serum concentrations of TSH and Prl remained constant throughout the cycle.
The gonadotrophin ratios Δ2:Δ1 were generally greater than 1. They increased from 1.4 in the early follicular phase to 3.0 in the late follicular phase, concomitant with the rise in oestrogens. The Δ2: Δ1 ratios for TSH and Prl were less than 1, ranging from 0.66 to 0.98 for TSH and from 0.26 to 0.99 for Prl. They did not show any cyclic changes.
Thus, this study shows that after LRH/TRH double stimulation, the gonadotrophin but not the Prl and TSH responses vary with the physiological changes in oestrogens during the menstrual cycle.
The supposed mechanism of oestrogen effects on pituitary hormone secretion and their possible clinical significance are discussed.
Glycoprotein hormone α-subunit secretion in patients with pituitary adenomas: influence of TRH, LRH and bromocriptine
Authors: MacFarlane I. A. , Beardwell C. G. , Shalet S. M. , Ainslie Gill , Rankin Elaine 
Published: December 2008

Abstract.
Twelve patients with pituitary adenomas and increased serum concentration of the glycoprotein hormone α-subunit were studied. Eight patients were acromegalic and one had a FSH1 producing tumour. The adenomas in 9 patients had undergone subtotal operative removal and/or external irradiation but no patient was studied within 3 months of these treatments.
Many of the acromegalic patients, with moderately elevated α-levels, showed marked increases in α-concentration after TRH and/or LRH, compared with controls. The non-acromegalic patients, with the highest α-levels, showed poor responses to releasing hormones. These results suggest that excessive α-subunit secretion in acromegalic patients is often under hypothalamic control whereas in non-acromegalic patients it is often autonomous.
Seven patients, 4 with acromegaly, were then given oral bromocriptine, 5 mg over 3 h. There was a significant fall in log mean α-level at 4 and 5 h (P < 0.02). Six patients took bromocriptine for 1–2 months. Log mean α-concentration was significantly reduced at the end of treatment (P < 0.02) and then recovered to basal levels after stopping treatment for one week. α-Subunit hypersecretion in some patients with pituitary adenomas is therefore modulated by dopaminergic control mechanisms.