bluuebunny/crossref_metadata_2025_split huggingface dataset:
Disturbances in sexual differentiation of rat foetuses following spironolactone treatment
Authors: Hecker A. , Hasan S. H. , Neumann F. 
Published: December 2008

Abstract.
Pregnant rats were treated with 40 mg spironolactone (sp) po from the 13th to the 21st day p.c. The foetuses were prepared and histologically examined on day 22. The male foetuses showed distinct signs of feminization especially of the external genitalia. The anogenital distance was nearly 48% shorter than that of the controls. The prostatic utricle persisted more distinctly, and the number and size of the prostatic buds were significantly reduced. The degree of feminization of the male foetuses which is achieved under the influence of sp (40 mg/day) is the same as that which can be induced by 1–3 mg cyproterone acetate.
Diurnal rhythms of immunoreactive N-acetylserotonin and melatonin in the serum of male rats
Authors: Pang S. F. , Yip M. K. , Liu H. W. , Brown G. M. , Tsui H. W. 
Published: December 2008

Abstract.
Immunoreactive N-acetylserotonin and melatonin in rat serum were extracted by ethyl acetate at ≤ pH 3 and chloroform at ≥ pH 10. respectively, following protein precipitation and were quantified by radioimmunoassays. There were diurnal rhythms of N-acetylserotonin and melatonin in the serum of rats (housed in 121/12d; lights on from 06.00–18.00 h for two weeks). Serum melatonin levels at 20.00–04.00 h are higher than those at 08.00–16.00 h. Serum N-acetylserotonin levels were, however, higher at 24.00–08.00 h and lower at 12.00–20.00 h. The concentration of N-acetylserotonin in individual samples ranged from a minimum of 0.45 ng/ml at 12.00 h to a maximum of 2.78 ng/ml at 08.00 h. The diurnal study on N-acetylserotonin levels in the rat serum was repeated and a similar result was obtained. The findings of the presence of N-acetylserotonin in the rat serum and a diurnal rhythm of serum N-acetylserotonin are in keeping with the notions that N-acetylserotonin may be secreted by the pineal gland and that N-acetylserotonin may be another indole with hormonal activities.
Distribution volume, metabolic clearance and plasma half disappearance time of exogenous luteinizing hormone releasing hormone in normal women and women with obesity and anorexia nervosa
Authors: Chikamori Kazumasa , Suehiro Fumie , Ogawa Toshiki , Sato Kei , Mori Hiroyoshi , Oshima Ichiyo , Saito Shiro 
Published: December 2008

Abstract.
Synthetic LRH was infused into normal women and women with obesity and anorexia nervosa to determine the distribution volume (DV), metabolic clearance rate (MCR) and half disappearance time (t½) of plasma LRH.
In normal women, the DV of LRH was 12.1 ± 0.9 (mean ± se) l, the MCR was 1478.9 ± 39.8 ml/min (28.5 ± 1.2 ml/min/kg body weight) and the initial t½ was 5.6 ± 0.4 min.
In obese patients the DV (20.6 ± 1.5 l) was significantly higher than that in normal subjects (P < 0.005), but the MCR and t½ were not significantly different from those in normal subjects.
In patients with anorexia nervosa the DV and MCR were 6.5 ± 1.1 l and 621.8 ± 110.5 ml/min (17.9 ± 2.4 ml/ min/kg body weight), respectively, which were both significantly lower than those in normal subjects (P < 0.02), while the t½ (7.3 ± 0.1 min) was longer than in normal subjects (P < 0.02).
These data suggest that 1) the abnormal responses of some hormones to provocation tests observed in obese patients and patients with anorexia nervosa should be evaluated in consideration of changes in the DV and metabolic clearance of hormones in these conditions, and 2) in patients with anorexia nervosa changes in MCR and t½ may reflect low metabolism of LRH.
New aspects of the physiological significance of LRH receptors of pituitary plasma membranes
Authors: Kuhl Herbert , Baumann Rudolf 
Published: December 2008

Abstract.
It has been found that l-cystine-bis-(4-nitroanilide), a synthetic peptidase substrate, competes with [125I]LRH for specific high affinity LRH receptors on isolated rat pituitary plasma membranes as effectively as a highly active LRH analogue. The pattern of [125I]LRH degradation by isolated pituitary plasma membranes was similar to that effected by pituitary and hypothalamic enzyme extracts. The enzyme activity seemed to accumulate in the supernatant of the membrane suspension after being released from the membrane structure.
Plasma membrane supernatant and pituitary and hypothalamic enzyme extracts were chromatographed together with labelled LRH on Sephadex G 200. This resulted in protein binding patterns with one peak at the fractions representing a molecular weight of 600 000 to 650 000 and another one of approximately 80 000, the first probably being an aggregate of the latter. After solubilization of the plasma membranes by Triton X-100, there was no evidence for another LRH receptor. There were also two peaks of [125I]LRH degrading activity (with identical metabolic pattern) and two peaks of arylamidase activity, which were, however, not identical with the binding peaks.
Both the arylamidase and the LRH binding-pattern had been demonstrated to be temperature- and hormonedependent, and seemed to be functionally related. The results indicate that there is a functional relationship between LRH binding-sites on plasma membranes and LRH degrading enzymes. This implies that the search for the 'true' LRH receptor has to be directed towards intracellular compartments of the pituitary gonadotrophs.
Quantitative studies of vasoactive intestinal peptide (VIP) binding sites and VIP-induced adenosine 3′:5′-monophosphate production in epithelial cells from duodenum, jejunum, ileum, coecum, colon and rectum in the rat
Authors: Prieto Juan C. , Laburthe Marc , Hoa Danièle Hui Bon , Rosselin Gabriel 
Published: December 2008

Abstract.
The binding of vasoactive intestinal peptide (VIP) and its effect on adenosine 3′:5′-monophosphate (cyclic AMP) production were measured in isolated rat intestinal epithelial cells from duodenum, jejunum, ileum, coecum, colon and rectum. In every segment tested, VIP binding and VIP-induced cyclic AMP production exhibited a similar pattern with two populations of VIP binding sites and similar magnitude of cyclic AMP production. Continuous displacement of the binding of 125I-labelled VIP and stimulation of cyclic AMP production were observed in the range of 10−10–10−7 m VIP concentrations. Fifty per cent inhibition of the initial binding of tracer was obtained with 2.2 to 3.2 nm VIP. The Km of stimulation of cyclic AMP production was 1.2 to 2.6 nm VIP.
Chicken VIP and porcine secretin showed a 4-fold higher and a 100-fold lower affinity than porcine VIP for binding sites, respectively. The same was true for the stimulation of cyclic AMP production.
The existence of receptors highly sensitive to VIP in the separate segments of the bowel corresponds to the presence of high concentration of VIP at the vicinity of epithelial cells and strongly suggests that VIP is active in regulating different intestinal functions.
Congenital adrenal hyperplasia due to partial 21-hydroxylase deficiency. A study of five cases
Authors: Bouchard Philippe , Kuttenn Frederique , Mowszowicz Irene , Schaison Gilbert , Raux-Eurin Marie-Charles , Mauvais-Jarvis Pierre 
Published: December 2008

Abstract.
Five women with post pubertal hirsutism due to a partial 21-hydroxylase deficiency were studied. These patients had no abnormalities of the external genitalia. They were compared to 3 adult women with a complete defect in 21-hydroxylase. The diagnosis of 21-hydroxylase deficiency was substantiated by the dramatic increase in 17-hydroxyprogesterone (17-OHP) after im injection of 250 μg synthetic ACTH (22 ± 12 nmol/l to 349 ± 153 nmol/l). However, in adult women with 21-hydroxylase deficiency recognized at birth and presenting abnormalities of the external genitalia, plasma 17-OHP was elevated in basal conditions (512 ± 106 nmol/l) and only slightly increased after ACTH administration (657 ± 133 nmol/l). Plasma cortisol levels determinated at 08.00 h were lower than normal in both groups but only slightly in groups with partial 21-hydroxylase deficiency. After ACTH stimulation, plasma cortisol levels remained lower than normal in all patients but with a noticeable increase in patients with partial defect. The differences noted between precocious and delayed onset virilization gave an indication of the importance of the enzyme defect. Plasma testosterone (T) and androstenedione (Δ4) levels were elevated both in basal conditions and after ACTH administration. However, in patients with delayed onset of hirsutism most circulating T seems to originate from peripheral conversion of Δ4 to T. Plasma ACTH values were strongly elevated in patients with a complete defect in 21-hydroxylase (260 ± 50 pg/ml) but normal in patients with partial deficiency (< 40 pg/ml).
In vitro testosterone 5α-reductase activity was determined in pubic skin homogenates from 4 patients with partial 21-hydroxylase deficiency. The amount of dihydrotestosterone + androstanediols formed from incubated [3H]testosterone was in the normal range for women. Virilization of patients with partial 21-hydroxylase deficiency therefore seems to be essentially due to an increase in active androgen production and not to exaggerated skin 'utilization' of pre-androgens as observed in idiopathic hirsutism.
Testosterone, dihydrotestosterone and androstanediols in plasma, testes and prostates of rats during development
Authors: Corpéchot Colette , Baulieu Etienne-Emile , Robel Paul 
Published: December 2008

Abstract.
Testosterone (T). 5α-dihydrotestosterone (DHT), 5α-androstane-3α, 17β-diol (3α-diol), and 5α-androstane-3β,17β-diol (3β-diol) have been measured in the plasma, ventral prostate, and testes of Sprague-Dawley rats with a specific radio-immunoassay, at birth, and then weekly until the 12th week.
In plasma, the T concentration is ∼ 0.3 ng/ml at birth and up to the 4th week; thereafter it increases steadily and reaches the adult level of ∼ 3 ng/ml by the 8th week. In male foetuses of 18 days gestation, the plasma concentration is 0.6 ng/ml. The 5α-metabolites taken together are at a higher concentration than that of T until the 7th week, and each one, after a broad maximum between 5–9 weeks, decreases promptly by the 10th week. The larger formation of 5α-metabolites from T in young rats has been confirmed by injection of the hormone to castrated males, which showed relatively more conversion at 5 than at 10 weeks.
In the ventral prostate, DHT is already high at 4 weeks (11 ng/g), and remain between 7 and 15 ng/g until the 12th week. T concentration is also larger than in plasma at 4th week (2 ng/g) and becomes approximately equal to the plasma value at puberty. A sharp peak of 3α-diol and 3β-diol is observed at the 8th week.
In the testes, T concentration is high at birth (183 ng/g), then declines rapidly, and increases again from the 5th week onward in parallel with plasma concentration. The concentrations of 5α-metabolites per testis vary in parallel to those in plasma, with the exception of sustained elevation of 3β-diol.
Age-related changes in the feedback regulation of gonadotrophin secretion by sex steroids in men
Authors: Muta Kazuo , Kato Ken-ichi , Akamine Yasuo , Ibayashi Hiroshi 
Published: December 2008

Abstract.
In order to clarify the age-related functional changes of the hypothalamic-pituitary-gonadal axis in men, the negative feedback control of serum gonadotrophin by sex steroids was studied in 39 young (18–34 years) and 49 elderly (62–95 years) men. Mean basal LH and FSH levels and the responsiveness to synthetic LRH were determined before and after daily im injection of testosterone propionate (TP; 5, 10 or 50 mg/day) or oestradiol benzoate (OeB; 50, 100 or 500 μg/day) for 3 days.
After the administration of TP or OeB, serum levels of testosterone or oestradiol were more elevated in the elderly than in the younger group. In the latter, basal LH level decreased significantly at 10 mg/day of TP and so did basal levels of both LH and FSH at 50 and 100 μg/day of OeB. Responses of serum LH and FSH to LRH were inhibited significantly by TP at a dose of 50 mg/day and by OeB at doses of 100 and 500 μg/day. Whereas in the elderly group, basal LH levels and responses of both LH and FSH were not suppressed significantly by TP regardless of the dose. At a dose of 500 μg OeB, serum LH response was decreased remarkably. Per cent suppression of serum LH response at 50 mg TP, as well as those of serum LH and FSH responses at 500 μg OeB in the elderly group, was significantly less than in the younger group. These data indicate that in the elderly men the regulatory system of gonadotrophin secretion appears to manifest a more marked resistance to inhibitory effects of sex steroids, and also suggest that the set-point to sex steroids in the hypothalamic-pituitary axis is reset at a higher level in male senescence.
Congenital familial thyroid aplasia
Authors: Stäger J. , Froesch E. R. 
Published: December 2008

Abstract.
A family with 4 siblings, 3 of which have hypothyroidism due to thyroid aplasia is described. A review of the literature revealed 10 families with familial occurrence of this disorder without other malformations. Therefore, thyroid aplasia or dysplasia should no longer be called 'sporadic cretinism' since autosomal recessive inheritance of this disorder appears to occur rather frequently.
A radioimmunoassay for human parathyroid hormone utilizing a goat anti-bovine PTH serum
Authors: Mallette L. E. 
Published: December 2008

Abstract.
An antiserum (NG-1) against bovine PTH (bPTH) generated in the domestic goat was characterized for use in the radioimmunoassay of PTH in human serum. When a carboxyterminal fragment of bPTH is used as radioligand, this antiserum detects only an antigenic site in the central region of the hPTH molecule. The synthetic hormone fragment, hPTH-(44-68), will displace 93% of the tracer, after which the addition of intact hPTH causes no further displacement. The assay does not detect the synthetic aminoterminal 1-34 fragment of the bovine or human hormones, nor the carboxyterminal fragment of the human hormone, hPTh-(53-84). Standard curves with bPTH-(1-84) and partially purified hPTH are not parallel, so that hPTH is used as standard. Serum from subjects with uraemia or primary hyperparathyroidism gives dilution curves parallel to that with the hPTH standard. The assay with NG-1 has been applied to the diagnosis of primary and secondary hyperparathyroidism, used to monitor the disappearance of PTH after parathyroidectomy, and for measurement of PTH in selective venous samples.
A change in the adrenocortical response in perinatal rat offspring given betamethasone 17,21-dipropionate
Authors: Hasegawa Y. , Yoshida T. , Fukiishi Y. , Mizushima Y. 
Published: December 2008

Abstract.
The potent synthetic glucocorticoid betamethasone 17,21-dipropionate (BMDP) produces adrenal hypertrophy in the rat foetus at late pregnancy by mediation of the hypothalamo-pituitary system, but causes adrenal atrophy, and acts as a normal glucocorticoid, in the adult rat. The change of the adrenal cortical response to the BMDP treatment was investigated in perinatal rat offspring. The pituitary ACTH potency was also determined in rat foetus treated with BMDP.
The time course of the adrenal corticosterone level after the BMDP treatment was similar to that of the plasma level on day 19 to 21 in the rat foetus from the adrenalectomized mother, both decreased at 2 h, but rose gradually at 4 h to 6 h, exceeding the control level at 24 h and 48 h after the BMDP treatment. The pituitary ACTH potency in the foetus decreased at 24 h and 48 h after the BMDP treatment, suggesting that ACTH released from the foetal pituitary stimulated adrenal corticoidogenesis. Maternal adrenalectomy did not essentially alter this stimulating activity of BMDP, which appeared in the perinatal rat offspring, only when BMDP was administered during the foetal period. These findings suggest that the hypothalamo-pituitary adrenocortical response to the treatment with BMDP drastically changes at the early neonatal age.
Recovery of the pituitary gland from LRH-induced refractoriness to LRH in the ovariectomized rat
Authors: Koiter T. R. , Pols-Valkhof N. , Schuiling G. A. 
Published: December 2008

Abstract.
Recovery of the pituitary gland from LRH-induced refractoriness to LRH was studied in 5-weeks ovariectomized rats. Rats first received over a period of 48 h an infusion of LRH at a rate of 416 ng/h. After discontinuation of this infusion pituitary LH content had decreased to about 50% of its original value and the rate of LH secretion decreased markedly. Over a period of 72 h after discontinuation of the infusion plasma LH values rose to pre-infusion values but pituitary LH content showed such a recovery only partly.
In another series of experiments a second infusion of LRH was given during 24 h and again at a rate of 416 ng/h, starting 3, 12, 24 or 72 h after discontinuation of the first infusion. It induced rises of LH secretion which were smaller than those following the first infusion, indicating refractoriness of the pituitary gland to LRH. However, the LH responses became progressively larger with increasing time intervals after the end of the first infusion. This stimulation of LH release was accompanied by a further decrease of pituitary LH content which was still depressed after the first infusion.
Comparison of plasma LH levels and pituitary LH content indicated that pituitary responsiveness to LRH can recover independently from pituitary LH content. It can also be concluded that the absolute value of the blood LRH concentration can not be the sole determining factor of LH secretion.
Regarding the validity of the endpoint response of the mouse (McKenzie) bioassay for thyrotrophin (TSH)
Authors: Ching Melvin 
Published: December 2008

Abstract.
The release of radiolabelled thyroid hormone into the circulation in low iodine fed mice has been used extensively as a bioassay for thyroid stimulating hormone (TSH). However, the specificity of several bioassays of pituitary hormones have been subject to question. Consequently, the validity of the assay endpoint for TSH in the mouse was re-evaluated with respect to the effect of luteinizing hormone (LH) whose chemical composition closely resembles that of TSH. Mice, prepared for bioassay of TSH received injections of purified LH or α or β subunits of LH. Identical doses of LH and LH subunits were quantified by LH and TSH radioimmunoassays and the results compared with those obtained by the bioassay. Microgram quantities of LH and subunits of LH elicited appreciable responses in the TSH bioassay but produced only negligible effects in the TSH radioimmunoassay. The response of the TSH bioassay of LH and α or β subunits of LH was 40–56% that obtained with LH radioimmunoassay. However, the pituitary concentrations obtained by TSH bioassay when compared with those obtained by radioimmunoassays for TSH, LH, or growth hormone (GH) paralleled closely the TSH radioimmunoassay data, although in terms of quantitative estimates, there was a 15-fold discrepancy between the TSH assays. Estimations of pituitary concentrations of LH lead to the conclusion that, at the doses normally employed, most crude rat pituitary extracts do not contain sufficient quantities of LH to alter significantly bioassayable (McKenzie) estimates of TSH.
Characterisation of breast skin temperature rhythms of women in relation to menstrual status
Authors: Phillips M. J. , Wilson D. W. , Simpson H. W. , Fahmy D. R. , Groom G. V. , Phillips M. E. A. , Pierrepoint C. G. , Blamey R. W. , Halberg F. , Griffiths K. 
Published: December 2008

Abstract.
Circadian breast skin temperature rhythms were characterised throughout the menstrual cycle, for various locations on the left breast of ambulatory women. All subjects exhibited highly significant circadian rhythms (P < 0.001). Changes in rhythm parameters, such as the mesor, amplitude and acrophase, were observed during the menstrual cycle. No consistent trend in these rhythm parameters was observed between subjects in relation to menstrual cycle stage. Experimental and statistical techniques used to characterise circadian rhythms in pre-menopausal women were applied to a post-menopausal woman with primary breast cancer. Comparison of rhythm parameters associated with the tumour area and corresponding site on the contralateral breast showed abnormal thermal characteristics such as elevated mesor values, decreased amplitude as well as changes in the timing of the acrophase. These properties may be exploited for the early detection of breast cancer. The project also involved the design and testing of an ambulatory device, known as the 'chronobra', for the measurement of breast skin temperature. The performance of the chronobra was in close agreement with reliable, conventional equipment. The chronobra now allows studies of breast skin temperature rhythms associated with breast disease to be extended.
Degradation of human chorionic gonadotrophin by human and rat tissues in vitro
Authors: Markkanen S. O. , Rajaniemi H. J. 
Published: December 2008

Abstract.
To determine what tissues are capable of degrading human chorionic gonadotrophin (hCG) in vitro, 125I-labelled hCG was incubated in various rat and human tissue homogenates. Some of the properties of the enzymes involved in the degradation processes were elucidated using enzyme modifiers. Degradation products of the hormone were analysed by gel filtration. In the liver and kidney homogenates the hormone was degraded into peptide fragments similar to the hormone subunits and further to smaller peptides and amino acids. Also blood cells, ovaries and human placenta were capable of cleaving the hormone into the subunits. The pH-optimum of the degradation reactions was 6.5. EDTA, DTT and 0.05% Triton X-100 slightly activated the reactions. Alkylating agents, such as N-ethylmaleimide and iodoacetamide inhibited both the subunit cleavage and the peptidolysis. Instead heavy metals, Hg2+, Cu2+ and Zn2+ inhibited mainly the peptidolysis. Phenylmethyl sulphonyl fluoride and ovomucoid trypsin inhibitor had no or a slight inhibition. An excess of unlabelled hCG or insulin inhibited the degradation reactions. The present results indicate that [125I]hCG is inactivated by the cleavage of the peptide fragments similar to the hormone subunits and peptidolysis and that different enzymes requiring free thiol-group(s) are involved in these processes. The observation of the degradation of [125I]hCG in placental tissue may have clinical significance in complicated pregnancies.