bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific interaction of radioactive anti-androgen TSAA-291 with androgen receptor in rat prostates
Authors: Sudo Katsuichiro , Yoshida Keiji , Nakayama Ryo 
Published: December 2008

Abstract.
A steroidal anti-androgen TSSA-291 (16β-ethyl-17β-hydroxy-4-oestren-3-one) bound to a macromolecular component in the cytosol of rat ventral prostates with high affinity (Kd = 5.0 × 10−9 m) and in a saturable manner. The number of binding sites was comparable to that for 5α-dihydrotestosterone (5α-DHT). [3H]TSAA-291 binding was effectively displaced by unlabelled 5α-DHT, 19-nortestosterone and cyproterone acetate but to a lesser degree by corticosterone. Glycerol density-gradient centrifugation analysis revealed that the sedimentation coefficeint of the [3H]-TSAA-291-macromolecule complex was 3–4.5 S. However, when the unlabelled cytosol was fractionated by glycerol density-gradient centrifugation before the binding of [3H]TSAA-291 was examined, specific binding of [3H]TSAA-291 was observed in fractions corresponding to 8–10 S. Binding of the [3H]TSAA-291-macromolecules complex to prostatic nuclei and DNA-cellulose was considerably less than binding by the [3H]5α-DHT-macromolecule complex. Instability of the TSAA-291 binding component on heat treatment before and after complex formation was also revealed and the results are discussed in terms of the anti-androgenic activity of TSAA-291.
Restoration of oestrogen-positive feedback effect on LH release in women with prolactinoma by transsphenoidal surgery
Authors: Koike Koji , Aono Toshihiro , Tsutsumi Hirohisa , Miyake Akira , Kurachi Keiichi 
Published: December 2008

Abstract.
The effect of hyperprolactinaemia on the hypothalamo-pituitary axis was assessed by iv injection of 100 μg luteinizing hormone releasing hormone (LRH) in 7 women with prolactinoma before and 3 months after normalization of the Prl level by transsphenoidal surgery. A dose of 20 mg of conjugated oestrogen (Premarin®) was also injected iv into patients with prolactinoma before and 4 months after surgery, and the serum LH levels were determined serially for 120 h after the injection. Surgical treatment caused significant reduction of the mean (± se) serum prolactin (Prl) level from 123.3 ± 7.8 to 19.4 ± 5.6 ng/ml. But the differences in the basal levels of LH (11.3 ± 2.2 to 8.6 ± 1.5 mIU/ml), FSH (8.3 ± 2.4 to 10.6 ± 3.7 mIU/ml) and oestradiol (26.6 ± 8.6 to 37.5 ± 5.5 pg/ml) before and 4 months after surgery were not significant. An exaggerated LH response to LRH in untreated prolactinoma patients was also observed after surgical treatment. After surgical treatment, patients showed LH release with a peak between 48 and 72 h after the injection of Premarin, whereas before treatment they did not show any LH discharge. The mean percent increase in LH between 48 and 72 h was also significantly higher after operation than before operation. These results suggest that the hyperprolactinaemia in prolactinoma patients may cause an impaired positive feedback effect of oestrogen on LH release and that this derangement can be reversed by reduction of the Prl level by adenomectomy.
Studies on the mechanism by which ACTH stimulates renin activity and angiotensin II formation in man
Authors: Oelkers Wolfgang , Köhler Angelika , Belkien Lutz , Fuchs-Hammoser Regina , Maiga Mahamane , Scherer Burkhart , Weber Peter C. 
Published: December 2008

Abstract.
Ten IU of ACTH (1–24) per day was infused for 34 h (starting at 7 a.m.) into 8 normal men on a constant diet containing 135 mm Na+ per day. All subjects retained between 152 and 181 mm of sodium. Potassium balance was negative. Plasma renin activity (PRA) and plasmaangiotensin II (P-A II) started to rise in most subjects after 6 to 8 h of infusion, reached a maximum after 24 h and then tended to decline. As shown previously, the rise in PRA is not due to a rise in plasma renin substrate concentration. Systolic, but not diastolic blood pressure increased significantly on the second day of ACTH-infusion. Plasma cortisol (P-F) was continuously stimulated by ACTH. Plasma aldosterone (P-aldo) increased rapidly 1 h after ACTH administration, then tended to fall, and increased again in most subjects, roughly in parallel with PRA. No significant changes in electrolyte balance, PRA, P-A II, P-F and P-aldo occurred in 3 subjects receiving 'sham'-infusions. Additional experiments in subjects treated with propranolol or indomethacin allowed the conclusion that the effect of ACTH on PRA and P-A II is not mediated by renal beta-adrenergic receptors, but perhaps (partially?) by prostaglandins. Since the infusion rate of ACTH was not much higher than the secretion rate of ACTH in the early morning hours, it is possible that ACTH is physiologically involved in the regulation of renin secretion.
Conversion of 22S-hydroxy-cholesterol and its effect on the metabolism of other sterols in rat adrenal cells and bovine adrenal mitochondria
Authors: Huijmans J. G. M. , Degenhart H. J. , Kortleve D. J. 
Published: December 2008

Abstract.
This study provides evidence that 22S-OH-cholesterol inhibits the conversion of 25-OH-cholesterol but has no effect on the conversion of 22R-OH-cholesterol. The latter sterol is an intermediate in the cholesterol side-chain cleavage, whereas for the conversion of 25-OH-cholesterol into pregnenolone the complete side-chain cleaving enzyme system is necessary. This complements a previous study in which it was shown, that 22S-OH-cholesterol has an inhibitory effect on the ACTH-induced conversion of cholesterol into corticosterone in isolated rat adrenal cells.
The available evidence thus suggests an inhibition by 22S-OH-cholesterol of the first step in the cholesterol side-chain cleavage.
The results, obtained from the experiments with rat adrenal cells and with bovine adrenal mitochondria, allow the hypothesis, that a causal relationship exists between conversion of 22S-OH-cholesterol and production of corticosterone, respectively pregnenolone.
We conclude, that 22S-OH-cholesterol is a substrate for steroid production in the adrenal cell. This sterol inhibits the ACTH-stimulated corticosterone production. The site of this inhibition is located at one of the first steps in the cholesterol side-chain cleavage, probably the binding of cholesterol to the cytochrome P450-complex.
Immunological aberration in primary hyperparathyroidism
Authors: Elias Alan N. , Sharma Brahma S. , Stokes John D. , Valenta Lubomir J. 
Published: December 2008

Abstract.
Altered immunological reactivity in primary hyperparathyroidism is suggested by the strong association between this disorder and malignancy. The present study was carried out to determine whether altered lymphocyte proliferation in response to common mitogens (PHA, Con-A, PWM) exists in primary hyperparathyroidism, and, if so, whether the abnormality resides in the lymphocytes or in humoral factors present in the plasma of patients with hyperparathyroidism. Ficoll-Hypaque purified lymphocytes from 6 patients with primary hyperparathyroidism and 4 normal volunteers were stimulated with PHA, Con-A and PWM in the presence of plasma from patients with primary hyperparathyroidism and normal AB+ plasma. The incorporation of [3H]thymidine in unstimulated (control) and stimulated cultures was determined. The results demonstrate that lymphocyte proliferation was significantly higher when both patients' and normal lymphocytes were stimulated with mitogens in the presence of patients' plasma. These findings suggest that plasma from patients with primary hyperparathyroidism contains a potentiator of lymphocyte mitogenesis, or, alternatively lacks an inhibitor of lymphocyte activation that is present in normal plasma.
Influence of nandrolondecanoate on the pituitary-gonadal axis in males
Authors: Bijlsma J. W. J. , Duursma S. A. , Thijssen J. H. H. , Huber O. 
Published: December 2008

Abstract.
Different anabolic steroids can exercise different effects on the pituitary-gonadal axis in males. During a pilot study regarding the possible beneficial effect of the anabolic steroid nandrolondecanoate (ND) on bone metabolism in patients with rheumatoid arthritis additional endocrinological parameters were studied. A significant decrease was found in the serum levels of testosterone, androstenedione and FSH and the ratio of testosterone/oestradiol. There was a significant increase in the serum levels of oestrone. The levels of oestradiol, SHBG, LH and cortisol remained unchanged.
An inhibitory effect of ND on testicular testosterone secretion is assumed. The decrease in androstenedione levels is explained by the diminished testosterone secretion. The rise in oestrone levels is explained by peripheral aromatizing of ND to oestrogens. The presented findings are in accordance with the hypothesis that sex steroids can act directly on the pituitary resulting in selective FSH and LH secretion. The possible role of the ratio testosterone/oestradiol in controlling gonadotrophin output is discussed.
Metabolic studies in women with previous gestational diabetes during contraceptive treatment: effects on serum lipids and high density lipoproteins
Authors: Rådberg Thomas , Gustafson Anders , Skryten Asbjörn , Karlsson Kirsten 
Published: December 2008

Abstract.
Triglycerides, cholesterol and phospholipids in serum and high density lipoproteins (HDL) were assessed in 11 women with previous gestational diabetes before and repeatedly during 6 months of low dose progestogen (lynoestrenol = LYN) contraceptive administration. Eight of these women also were followed in an identical manner during non-hormonal contraception (IUD) and 6 of them during combined oral contraceptive administration (EE + LYN).
During the use of IUD or LYN administration neither serum nor HDL lipids changed. The combined OC, EE + LYN, increased serum triglycerides progressively: 73% (P<0.01) after 6 months concomitant with a 100%-increment of HDL triglycerides (P< 0.01). HDL-cholesterol and -phospholipids were not consistently changed. The EE + LYN induced alterations differed from the effects of LYN alone (P< 0.01).
These results suggest that low dose progestogens, such as LYN, could be considered as contraceptive alternatives in women with gestational diabetes. However, combined OC should be avoided in these patients. The present findings differ from those obtained in insulin-dependent diabetics and suggest that a diabetic prediposition enhances the effects of synthetic oestrogens and/or diminishes some of the effects of progestogens on lipid metabolism.
Microautoradiographic studies on distribution of 5α-dihydrotestosterone, cyproterone acetate and oestradiol-17β in human prostatic hyperplasia tissue transplanted to juvenile rats
Authors: Ruberg I. , Senge Th. , Neumann F. 
Published: December 2008

Abstract.
While maintaining the actual conditions prevailing in benign prostatic hyperplasia (BPH) in man, transplantation of BPH tissue to newborn rats proved a suitable model for examining the distribution of sexual hormones in different tissue compartments of BPH. In combination with the microautoradiographic method, it was possible to demonstrate the residence of the radioactive androgen 5α-dihydrotestosterone (5α-DHT), the antiandrogen cyproterone acetate (CA) and the oestrogen oestradiol-17β (E2) in the epithelium and/or stroma of human BPH tissue. Quantitative evaluation in the form of a point per area count on photographic pictures yielded a silver grain distribution ratio in epithelium and stroma of 1.3:1 and 1.5:1 for epithelium to stroma after administration of [3H]5α-DHT and [3H]CA administration respectively and 0.5:1 after [3H]E2.
The high tracer recovery rate throughout the stroma following E2 administration supports the current view that the stromal proliferation is attributable mainly to oestrogen influences.
The relatively high silver particle proportion throughout the stroma following 5α-DHT administration corroborates recent findings which suggest that the exclusive androgen dependency of the glandular epithelium can only be considered in conjunction with an active metabolization of androgens in the stroma.
The correspondence in the distribution of the radioactive tracer after [3H]5α-DHT and [3H]CA administration both in the epithelium and stroma suggests that an antagonism may also exist in the stroma.
Effects of a dopamine antagonist (metoclopramide) on the release of the adenohypophyseal hormones in amenorrhoeic patients with and without hyperprolactinaemia
Authors: Seki Katsuyoshi , Uesato Tadashi , Kato Koichi 
Published: December 2008

Abstract.
To obtain further insight into the role of endogenous dopamine (DA) on the adenohypophyseal hormones release in amenorrhoeic women, responses of the adenohypophyseal hormones to a DA antagonist, metoclopramide (MCP), were evaluated in 4 normal women, in 9 normoprolactinaemic-amenorrhoeic patients, and in 7 hyperprolactinaemic-amenorrhoeic patients. The hyperprolactinaemic-amenorrhoeic patients were, in the majority, without a demonstrable micro-adenoma. Maximal net increase of prolactin (Prl) after MCP administration were lower (P < 0.01) in hyperprolactinaemic patients compared with those seen in normal women or in normoprolactinaemic-amenorrhoeic patients. Administration of MCP resulted in significant elevation in serum FSH, LH and TSH in hyperprolactinaemic patients, but neither in normal women nor in normoprolactinaemic-amenorrhoeic patients. These findings suggest an increased dopaminergic inhibition of the release of TSH as well as FSH and LH in hyperprolactinaemic-amenorrhoeic patients.
Benserazide and nomifensine in the diagnosis of prolactin-secreting pituitary adenomas
Authors: Pontiroli A. E. , Loda G. , Roggia A. , Scagliola P. , Falsetti L. 
Published: December 2008

Abstract.
Benserazide, an inhibitor of dopa-decarboxylase, stimulates prolactin (Prl) release in normal women and in puerperae; nomifensine, a dopaminergic drug able to release dopamine and to inhibit its re-uptake at the post-synaptic level, inhibits Prl release in the same subjects. Similar modifications of Prl release are evident in selected cases of non-tumoural hyperprolactinaemia, while neither drug modifies Prl release in patients with a Prl-secreting pituitary adenoma. The aim of our study was to compare the effect of these drugs in patients with a Prl-secreting pituitary adenoma, in patients with 'functional' hyperprolactinaemia and in patients with minor abnormalities of sellar tomography. Neither drug modified Prl release in patients with macro- or microadenomas; several patients in the remaining groups failed to respond to one or both tests, the concordance between the two tests averaging 75%. Patients responding to both tests, to one test or to neither test showed progressively higher basal Prl levels.
Since benserazide and nomifensine can indicate the presence of a pituitary adenoma earlier than sellar tomography, our results indicate that patients with no Prl response to one or to both tests probably harbour a pituitary adenoma which cannot yet be revealed by sellar tomography.
Thyrotrophin-binding-inhibition assay: comparison of crude and purified membrane preparations
Authors: Garcia Angeles A. , Hunter Anthony N. , Wilkins John A. , von Westarp Christian 
Published: December 2008

Abstract.
Two different thyroid membrane preparations (TMP), crude and pure, made from a homogenate of normal human thyroid tissue, were used to test purified serum IgG from 36 patients with Graves' disease, and 10 normal control subjects, in the thyrotrophin-binding-inhibition (TBI) assay. All reagents for the assay were identical, and aliquots of each IgG were tested in both TMP simultaneously, under exactly comparable conditions. Blood was drawn while the patients were hyperthyroid (19), euthyroid (13), or hypothyroid (4); 15 of the patients were untreated and 21 were being treated. The frequency of positive TBI was similar in both TMPs and highest among the 131I-treated patients. Comparison of TBI results in both TMP for each IgG sample revealed wide differences, and 47.1% of the Graves' IgGs were TBI positive in one membrane preparation, while negative in the other. There was no correlation of TBI values between the two TMP, or with clinical status, or the presence of standard thyroid antibodies.
The findings indicate that the IgGs of Graves' disease, as now tested in the TBI assay, bind heterogeneous to different fractions of the thyroid membranes.
Testicular receptors of human chorionic gonadotrophin in adult men. Binding and degradation of the hormone
Authors: Grizard Geneviève , Boucher Daniel , Hermabessière Jean , Grizard Jean 
Published: December 2008

Abstract.
Binding and degradation of human chorionic gonadotrophin (hCG) to testicular tissue obtained by biopsy from 9 men with gonadal disorders were investigated. Vacant hCG receptors were assayed in partially purified testicular homogenates using [125I]hCG (radio-iodinated with chloramine T). Degradation of [125I]hCG during exposure to human testicular preparations was measured in terms of the ability of supernatants to specifically bind to rat testicular receptors.
Binding of [125I]hCG was time and temperature dependent. At 37°C, a maximum was reached at 8 h. It was also found to be a saturable process with respect to homogenate and hormone concentrations. Association constants and number of binding sites determined in 9 men, using Scatchard plot and saturation curve analysis ranged, respectively, from 0.2 to 1.8 × 1010m−1 and from 92 to 3427 fmol/g testis or 7 to 380 fmol/mg protein. Degradation of [125I]hCG increased with temperature and time of exposure to human testicular homogenate. It increased also with increasing human testicular homogenate concentration and substrate concentrations. For a similar concentration of [125I]hCG, per cent of degraded hormone ranged from 32 to 57, according to the subjects. These results show that human testicular homogenates are capable of binding and degrading hCG in vitro. Biological and physiological implications of degradation for hormone binding are discussed.
Ontogeny of thyroid peroxidase activity in perinatal rats
Authors: Fukiishi Y. , Harauchi T. , Yoshizaki T. , Hasegawa Y. , Eguchi Y. 
Published: December 2008

Abstract.
The ontogeny of thyroid peroxidase (TPO) activity was investigated in rat foetuses and neonates. From day 19 to 22 of gestation in intact pregnant rats, the TPO activity in their foetuses increased with foetal age.
Following maternal treatment with propylthiouracil (PTU), the TPO activity markedly increased in foetuses on and after day 20 of gestation. The TPO activity in encephalectomized foetuses increased as markedly as that in intact littermates, whereas that in hypophysectomized littermates failed to increase.
Newborn rats nursed by mothers treated with PTU had a TPO activity similar to that in controls of untreated mothers. There was also no difference in the TPO activity between hypophysectomized adult females and intact adult ones.
These observations show that in foetal rats, TPO activity increases disproportionately to the thyroid weight, but not in newborn and adult rats, and suggest that preferential synthesis of this enzyme occurs in addition to cell hypertrophy during foetal life.
Developmental patterns of levels of corticosterone and of corticosterone binding in the serum of female rats: effects of ovariectomy and adrenalectomy
Authors: Vallette G. , Delorme J. , Benassayag C. , Savu L. , Nunez E. A. , Meijs-Roelofs H. M. A. , Kramer P. 
Published: December 2008

Abstract.
Corticosterone concentrations and corticosterone binding in the serum were studied in immature female rats, using radioimmunoassay and batchwise gel equilibration techniques. A parallel developmental pattern was found for corticosterone levels and its serum binding with a neonatal drop, followed by low levels until 12 days of age and a rise between 12 and 28 days of age.
Effects of adrenalectomy, of ovariectomy, of the combined operation and of sham-operations, performed at various ages, were also studied. Adrenalectomy performed at 5 days of age did not decrease serum corticosterone concentrations within a 6-day period whereas it did in older rats. Complete disappearance of corticosterone from the blood occurred only in adult rats after combined adrenalectomy/ovariectomy.
Ovariectomy and sham-operations in the younger age groups (5–15 days) caused a gradual increase in corticosterone concentration with maximal values 6 days after operation or later. The response of corticosterone secretion to these operations became more moderate and quicker, i.e. more adult-like, at 28 days of age, the age where corticosterone concentrations in intact rats also seemed to reach a plateau at an adult-like level.
Corticosterone binding changed only marginally after ovariectomy or sham-operations until 28 days of age, when an increase was induced by these operations. After adrenalectomy or combined adrenalectomy/ovariectomy, however, marked increases in serum binding of corticosterone were always seen. In summary: though a parallel developmental pattern of serum corticosterone levels and corticosterone binding was seen in the maturing rat, interference with the normal condition causes divergent responses in these two parameters. Moreover, the responses vary with maturational age.
Prolactin in the circulation of chronically catheterised piglet foetuses and pregnant sows, and the effect of thyrotrophin-releasing hormone
Authors: Macdonald Alastair A. , Bevers Mart M. , Ellendorff Franz , Taverne Marcel 
Published: December 2008

Abstract.
We chronically catheterised 12 piglet foetuses and 11 sows to determine the changes in circulating concentrations of prolactin during the last 2 weeks of gestation. Prolactin levels were measured by homologous radioimmunoassay and were found to average 2.12 ± 0.23 ng · ml−1 in the foetuses and 4.19 ± 0.84 ng · ml−1 in the sows. Foetal concentrations of prolactin increased significantly during the time period of the study. There was no change in maternal concentrations over the corresponding time. Injection of 5 μg TRH into 7 foetuses increased the plasma concentrations of prolactin in 6 animals, produced no apparent change in the seventh foetus and did not affect maternal concentrations of prolactin. The magnitude of the maximum response to TRH of the younger foetuses (< 107 days Δ = 0.7, 1.3, 4.2 ng · ml−1) was substantially less than that of the foetuses prior to term (> 107 days Δ = 6.4, 21.7, 27.5 ng · ml−1). Injection of saline and the haemorrhage of blood sampling produced no significant change in the initial concentration of prolactin. We conclude that prolactin is present in the circulation of the pig foetus, that it is produced endogenously in lower concentrations than in the pregnant sow and that the foetal responsiveness to TRH stimulation increases towards the end of gestation.
Hormonal and metabolic effects of intravenous infusion of prostacyclin in healthy women
Authors: Ylikorkala Olavi , Knip Mikael , Mäkäräinen Leo , Pakarinen Arto , Viinikka Lasse 
Published: December 2008

Abstract.
To study the hormonal and metabolic effects of prostacyclin (PGI2), 6 healthy women were infused iv with PGI2 (1, 2, 4, and 8 ng/kg/min, each for 20 min) dissolved in glycine buffer, or with glycine buffer only. Serial blood samples collected before, during and after the infusion were assayed for FSH, LH, prolactin, growth hormone, thyrotrophin, oestradiol, progesterone, testosterone, cortisol, thyroxine, triiodothyronine, renin, aldosterone, glucose, insulin, glucagon, cholesterol, high density lipoprotein-cholesterol, triglycerides, alkaline phosphatase, alanine and aspartate aminotransferases, bilirubin, sodium, potassium, chloride, calcium, inorganic phosphorous, creatinine and uric acid. PGI2 infusions were accompanied by increased levels of prolactin, growth hormone and cortisol, probably due to the stressful side-effects during PGI2 infusion. In addition, plasma renin activity, glucagon and blood glucose increased, whereas the other variables measured did not change. These PGI2-effects should be kept in mind, when PGI2 is used in clinical practice.