bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reversible inhibition of sperm production and gonadotrophin secretion in men following combined oral medroxyprogesterone acetate and percutaneous testosterone treatment
Authors: Soufir Jean-Claude , Jouannet Pierre , Marson Jocelyne , Soumah Arlette 
Published: December 2008

Abstract.
Six men requesting male contraception received a daily oral dose of 20 mg medroxyprogesterone acetate (MPA) in combination with 50 or 100 mg percutaneous testosterone for 1 year. From the third month the sperm concentration was < 106/ml for all the men at one time or another during treatment, and usually < 5 × 106/ml, with an average reduction of 95% with respect to pre-treatment values. The sperm count returned to previous values 3–6 months after cessation of the treatment. While FSH and LH secretion was inhibited throughout the treatment period, plasma testosterone levels were not reduced. Oestradiol levels were unaffected while dihydrotestosterone was elevated. The secretory activity of the prostate and seminal vesicles was not appreciably affected; seminal carnitine concentration was reduced during the treatment with a subsequent return to pretreatment values. No pregnancies occurred during treatment. There was no impairment of libido in the subjects, nor any incidence of gynaecomastia, or increase in average body weight. The only observed metabolic side-effect was a moderate increase in glycaemia. A synergistic action of MPA and testosterone is proposed to explain the inhibition of gonadotrophin secretion.
Urinary free corticoids: an evaluation of their usefulness in the diagnosis of Cushing's syndrome
Authors: Trecan G. Vidal , Laudat M. H. , Thomopoulos P. , Luton J. P. , Bricaire H. 
Published: December 2008

Abstract. We evaluated the usefulness of measurement of urinary free corticoids (UFC) in the diagnosis of hypercorticism. One hundred and thirty patients with features suggestive of Cushing's syndrome were examined. Twenty-six patients were proved to have Cushing's syndrome. The remaining 104 patients were considered not to have this disease on the basis of other investigations, and were designated as 'suspected patients'. UFC and 17-hydroxycorticosteroids were measured in all these patients in the basal state and on the 5th day of a low-dose-dexamethasone suppression test (3 mg/day for 5 days). UFC values of patients with Cushing's syndrome were well above 125 μg/24 h in the basal state and higher than 10 μg/24 h during the suppression test. UFC values of 'suspected patients' were between 20 and 125 μg/24 h in the basal state and below 10 μg/24 h during the suppression test.
It can be concluded that the measurement of UFC in the basal state and on the 5th day of a suppression test is not only a very sensitive but also a specific method for the diagnosis of Cushing's syndrome.
Dyslipoproteinaemia in hypothyroidism of pituitary origin: effects of l-thyroxine substitution on lipoprotein lipase, hepatic lipase, and on plasma lipoproteins
Authors: Valdemarsson Stig , Hedner Pavo , Nilsson-Ehle Peter 
Published: December 2008

Abstract. We have studied the effects of l-thyroxine substitution on lipoprotein concentrations, on the activities of lipoprotein lipase (LPL) and hepatic lipase (HL), and on the elimination rate of exogenous triglyceride in a homogeneous group of patients with hypothyroidism of pituitary origin. All were deficient of sex hormones but not of corticosteroids during the observation period.
Before treatment total plasma cholesterol, LDL cholesterol, and triglyceride levels were significantly higher than in a euthyroid control group but not as high as in patients with overt primary hypothyroidism. The activities of LPL and HL were also intermediate between those of euthyroid and overt primary hypothyroid subjects, and there was a significant reduction of the elimination rate of exogenous triglyceride. No changes were found for HDL cholesterol levels.
When the patients with secondary hypothyroidism were compared to patients with primary hypothyroidism, matched for thyroid function levels, age, sex, and weight, there were no differences with regard to plasma lipoprotein concentrations or post-heparin lipase activities.
In 3 patients with secondary hypothyroidism the lipoprotein profiles were studied by zonal ultracentrifugation and found to agree well with changes observed in primary hypothyroidism.
l-thyroxine substitution produced a normalization of lipase activities and lipoprotein concentrations in patients with secondary hypothyroidism. We conclude that there are no fundamental differences in the disturbances of the lipoprotein metabolism in primary and secondary forms of hypothyroidism.
Immunohistochemical localization of thyroxine (T4) and triiodothyronine (T3) in the rat thyroid gland under various experimental conditions
Authors: Kawaoi Akira , Okano Tadao , Nemoto Norimichi , Shikata Toshio 
Published: December 2008

Abstract. Detection of T4 and T3 in paraffin sections of the rat thyroid gland in various functional states was attempted by an immunoenzyme technique. Both hormones showed a similar localization, being detected mainly in the colloid in the follicular lumen, and sometimes in certain regions of the cytoplasm of the follicular epithelium. Following administration of TSH, their stainability was increased, and the localization within the cytoplasm became more remarkable. Decrease or disappearance of stainability was observed after hypophysectomy or administration of PTU.
These findings support the view that the immunostainability of T4 and T3 is closely correlated with the functional state of the thyroid gland.
Primary hyperparathyroidism associated with primary hyperaldosteronism
Authors: Ferriss J. B. , Brown J. J. , Cumming A. M. M. , Fraser R. , Lever A. F. , Peacock M. , Robertson J. I. S. 
Published: December 2008

Abstract. Two patients with both primary hyperparathyroidism and primary hyperaldosteronism are described. Each presented with high blood pressure and a history of renal calculi. Mild hypercalcaemia was associated with raised plasma parathyroid hormone concentrations and a parathyroid adenoma was excised from each. Both patients also had hypokalaemia, hyperaldosteronism and low plasma renin concentrations. Quadric analysis, adrenal vein plasma aldosterone concentrations, adrenal venography and CT scanning all suggested an adrenal adenoma in each patient. This suspicion was confirmed at operation in one patient; the other patient is unfit for adrenal surgery but her blood pressure and plasma potassium concentration have remained within the normal range during prolonged treatment with either spironolactone or amiloride.
Because of this unusual association a search was made for parathyroid hormone excess in patients with primary hyperaldosteronism and for aldosterone excess in primary hyperparathyroidism. None was found.
Effects of naloxone on the insulin and GH responses to α-adrenergic stimulation with clonidine
Authors: Massara F. , Limone P. , Cagliero E. , Tagliabue M. , Isaia G. C. , Molinatti G. M. 
Published: December 2008

Abstract. To find if endorphins can influence hormonal responses mediated by noradrenergic pathways, we examined the effects of naloxone, an opiate receptor blocker, on the GH and insulin responses to clonidine, a drug which acts by stimulation of α-adrenergic receptors. Intravenous clonidine (0.15 mg in 10 min) induced a significant fall of plasma insulin and a marked increase of plasma GH.
Intravenous naloxone (bolus of 1.6 mg followed by 50 μg/min) did not change the insulin response to clonidine, and seemed to induce only a slight delay in the GH response.
Prenatal testosterone propionate and postnatal ovarian activity in the rat
Authors: Slob A. Koos , den Hamer R. , Woutersen P. J. A. , van der Werff ten Bosch J. J. 
Published: December 2008

Abstract. Testosterone propionate (TP) was given to rats on days 16 through 20 of pregnancy (2 mg/day). Female young had masculinized external genitalia. Sexual maturity was accelerated in TP females, despite lower weights and shorter lengths of body and tail. Placental and body weights were lower in TP females and males than in controls. The inhibiting effect of TP on postnatal growth is probably mediated by its effect on birth weight through placental damage. Ovarian cyclicity occurred upon reaching sexual maturity. In one experiment TP females were ovariectomized at 6 weeks, and given ovarian and vaginal grafts. Most of these animals showed regular cyclicity in vaginal smears between 74–100 days. Thus neither the 'early', nor the 'delayed early androgen syndrome' occurred in these experiments.
This absence of effect of prenatal TP on ovarian cyclicity is attributable to a placental barrier for testosterone. When maternal plasma testosterone was raised 20-fold by exogenous TP, foetal testosterone levels remained unchanged. More detailed information was obtained when labelled testosterone was infused into a pregnant rat. Testosterone did not reach the foetus as such, but mainly as androsterone, which cannot be converted into oestrogens. This explains why prenatal TP can cause masculinization of genitalia, without 'masculinizing' the gonadotrophin secretion pattern in female rats. The latter process would presumably require oestrogenic compounds.
Effects of trifluoperazine on rat prolactin, growth hormone, thyroid stimulating hormone and adrenocorticotrophin secretion in vitro
Authors: Powell Ruth C. , Daniels Mark , Innes Graham K. , Ashby Michael J. , Mashiter Keith 
Published: December 2008

Abstract. We have studied the effects of trifluoperazine, a proposed inhibitor of calmodulin directed cellular function, on adrenocorticotrophic hormone (ACTH), thyroid stimulating hormone (TSH), prolactin (Prl) and growth hormone (GH) secretion from primary cultures of rat adenohypophyseal cells. 5 × 10−6 m and 10−5 m trifluoperazine caused a significant (P < 0.005) reversible dose-related decrease in basal Prl secretion but was less effective on basal GH secretion, significant reversible inhibition (P< 0.005) occurring only with 10−5 m. Trifluoperazine did not consistently alter basal ACTH or TSH secretion but did inhibit 10−2 m theophylline stimulation of ACTH, Prl and GH secretion and 1.5 × 10−7 m TRH stimulation of TSH and Prl secretion. Paradoxically 10−5 m trifluoperazine enhanced theophylline stimulation of TSH secretion.
Our results show trifluoperazine to have differential effects on Prl, GH, ACTH and TSH secretion, which are consistent with the known calcium dependence of pituitary hormone secretion and may suggest a role for calmodulin in this process.
Effects of iodotyrosine deiodinase inhibition on serum concentrations and turnover of diiodotyrosine (DIT) and thyroxine (T4) in the rat
Authors: Meinhold Harald , Buchholz Reinhard 
Published: December 2008

Abstract. Serum concentrations and metabolic clearance rates (MCR) of diiodotyrosine (DIT) and thyroxine (T4) have been measured by radioimmunoassay and tracer kinetic technique in both normal rats and rats treated with 3-nitro-l-tyrosine (MNT), a potent inhibitor of iodotyrosine deiodinase. In normal rats, DIT serum levels were 0.27 ± 0.12 nmol/l (mean ± sd); MCR was 15.9 ml/h 100 · g body weight (bw), and the turnover rate was 4.3 pmol/h · 100 g bw. Inhibition of iodotyrosine deiodination by treatment with 50 μmol MNT per day for 1 week caused a highly significant elevation of DIT serum levels to 4.80 ± 3.30 nmol/l, a decrease of MCR to 9.0 ml/h · 100 g bw and a ten-fold increase of the DIT turnover rate to 43.2 pmol/h · 100 g bw. Serum concentrations of T4 and T3 decreased slightly, whereas the T4 turnover rate (37.5 vs 37.8 pmol/h · 100 g bw) and rT3 serum levels remained unchanged under MNT treatment.
The study demonstrates the presence of measurable DIT serum concentrations in the normal rat. Inhibition of intra- and extrathyroidal iodotyrosine deiodinase leads to a situation in which circulating iodotyrosines play an equally important role in peripheral iodine turnover as the iodothyronines. Since DIT serum levels in normal and enzyme-blocked rats were comparable to those in normal human subjects and patients with iodotyrosine deiodinase defect respectively, MNT-treated rats afford a suitable experimental model for this disease.
Immunohistochemical demonstration of salivary proline rich peptide P-C like immunoreactivity in human pancreatic B-cells
Authors: Ito Seiki , Isemura Satoko , Saitoh Eiichi , Sanada Kazuo , Suzuki Toshimitsu , Shibata Akira 
Published: December 2008

Abstract. Antisera against proline rich peptide P-C, recently isolated from human whole saliva were raised in rabbits by injections of peptide P-C-BSA conjugates. Immunohistochemical study using the antisera was carried out on human salivary glands, gut and pancreas. The results showed that peptide P-C like immunoreactivity was present not only in the salivary glands but also in the pancreatic islets, though not in the gut. Furthermore, immunostaining of adjacent thin sections revealed that cells reacting with antisera against peptide P-C were identical to those reacting with insulin antisera. As the antisera against peptide P-C did not have any cross-reactivities to insulin, glucagon, somatostatin, pancreatic polypeptide, VIP and human C-peptide, the antisera were considered to recognize specifically either peptide P-C related antigen or peptide P-C itself in human pancreatic B-cells. A novel substance, peptide P-C like immunoreactivity, may be present in pancreatic B-cells independent of pro-insulin and insulin.
Morphological similarity between the salivary glands and the pancreas has been reported, and amylase, kallikrein and glucagon are present in both. These findings seem to suggest some functional relation between the pancreas and salivary glands. Detection of peptide P-C like immunoreactivity in the pancreas and salivary glands would be a additional support for this idea. Although it is suggested that peptide P-C like immunoreactivity in pancreatic B-cells may play some role in the function of B-cells, its exact pathophysiological role remains obscure.
Hormonal effects of beta-receptor blockade during exercise
Authors: Johansson G. , Uusitupa M. , Härkönen M. , Siitonen O. , Aro A. , Korhonen T. 
Published: December 2008

Abstract. The effects of two different beta-receptor blocking agents, beta1-selective metoprolol (150 mg/day) and non-selective propranolol (120 mg/day), on hormonal responses to physical exercise (30 min bicycle ergometer test) were compared with placebo within a double-blind, cross-over design in 7 healthy male volunteers.
Plasma prolactin levels decreased from the initial values during and after exercise during treatments with placebo and beta-receptor blocking agents, but they were constantly higher with the two beta-blocking agents than with placebo. Exercise did not affect plasma testosterone levels, but during propranolol they remained higher than during placebo and metoprolol. The plasma LH and FSH levels were not affected by exercise, nor were they significantly modified by beta-blockade.
The results of this study as well as those of previous studies indicate that beta-receptor blocking agents interfere with physiological endocrine functions and that the non-selective agents may have more distinct effects in this respect.
Effect of an enkephalin-analogue (FK 33-824) on glucose tolerance in man
Authors: Jeanrenaud X. , Maeder E. , Del Pozo E. , Felber J. P. 
Published: December 2008

Abstract. The purpose of the present work was to study the effect of a methionine-enkephalin analogue (FK 33-824) on glucose tolerance in man. Groups of 5 to 8 normal subjects were given a 0.5 mg im injection of the drug or placebo just before a 100 g oral glucose load or a 0.5 g/kg iv glucose load. In the enkephalin analogue treated subjects, diminished insulin response to glucose was observed following the oral glucose load, with insulin values significantly lower than in the controls from time 10 to 90 min, but no corresponding change in the glucose curve. This effect was not observed when glucose was given iv in another group of 5 subjects in whom the significant blunting of the insulin response was accompanied by a significant decrease in glucose tolerance.
These observations demonstrate that in man, enkephalin produces a decrease in insulin secretion in response to both oral and iv glucose loads. The absence of any marked impairment in glucose tolerance in the oral test in spite of the decreased insulin response suggests that enkephalin might have an additional effect in delaying glucose absorption.
Influence of dopaminergic inhibition on serum levels of thyrotrophin and prolactin in patients with hypothyroidism before and after prolonged oral administration of TRH
Authors: Frey Harald M. M. , Haug Egil 
Published: December 2008

Abstract. Forty mg TRH/day given orally for 3 weeks to 8 patients with mild primary hypothyroidism decreased serum TSH from a mean of 4.0 ng/ml ± 1.2 (se) to 2.0 ng/ml ± 0.4 (49%), and their mean incremental TSH response to iv TRH was equally reduced from 8.6 ng/ml ± 2.5 to 4.0 ng/ml ± 1.9 (46%). In the same patients serum Prl was 8.2 ng/ml ± 2.2 before oral TRH treatment and 6.6 ng/ml ± 1.5 (81%) after treatment, and the mean incremetal Prl response to iv TRH was reduced from 43.5 ng/ml ± 5.0 to 35.9 ng/ml ± 7.5(83%).
The oral administration of 10 mg of the dopamine antagonist metoclopramide increased mean serum TSH from 0.6 ng/ml ± 0.1 (se) to 0.7 ng/ml ± 0.1 (120%) in euthyroid subjects and from 4.0 ng/ml ±1.2 to 5.7 ng/ml ± 1.6 (145%) in patients with primary hypothyroidism, and mean serum Prl from 8.6 ng/ml ± 0.8 to 109.5 ng/ml ± 24.3 (1251%) and from 8.2 ng/ml ± 2.2 to 119.6 ng/ml ± 45.5(1460%), respectively.
The incremental TSH responses to iv TRH increased 2.3-fold in euthyroid subjects pre-treated with metoclopramide, while no change was observed in the TSH responsiveness in patients with primary hypothyroidism following metoclopramide pre-treatment. In the euthyroid subjects metoclopramide treatment had no effect on the Prl response to iv TRH. In the primary hypothyroid group metoclopramide pre-treatment caused a reduced Prl response to iv TRH in more than 50% of the patients. It is concluded that long-term TRH treatment decreased the serum levels of TSH and Prl as well as the incremental increases in TSH and Prl to iv TRH stimulation in patients with primary hypothyroidism. Long-term TRH treatment did not change the TSH and Prl responses to the dopamine antagonist metoclopramide.
Effects of PGF2α and indomethacin on ovulation and steroid production in the isolated perfused rabbit ovary
Authors: Holmes Paul V. , Janson Per O. , Sogn Jan , Källfelt Björn , LeMaire William J. , Ahrén Kurt B. , Cajander Stefan , Bjersing Lars 
Published: December 2008

Abstract. Both ovaries of 31 rabbits were perfused with a chemically defined medium in vitro in a recirculation system. In one series of experiments, hCG (100 IU) was injected iv 5–6 h prior to anaesthesia and surgery. Approximately 1 h later the perfusion was started. One ovary was perfused as control while the other ovary was perfused with 5 μg/ml indomethacin or with indomethacin and 1 μg/ml PGF2α. In another series of experiments the rabbits received no pretreatment prior to operation. Instead, bovine LH was added to the perfusion medium of both control and experimental ovaries. The experimental side also received either indomethacin or indomethacin and PGF2α. Finally, the effect of PGF2α in the absence of LH was compared to the control ovary receiving only LH.
After injection of hCG in vivo, ovulations occurred in 4 of 5 control ovaries. Indomethacin completely blocked ovulation in 4 of the 5 ovaries treated, while PGF2α restored ovulations in all the experimental ovaries. In the group of experiments where LH was added in vitro, ovulations were induced in all ovaries treated with varying LH doses. Furthermore, indomethacin blocked ovulation in 5 out of 7 ovaries, and PGF2α restored ovulation in all ovaries. Fifty per cent of the ovaries treated only with PGF2α (in the absence of LH) also ovulated. The pattern of steroid release did not differ between control ovaries, indomethacin treated ovaries, and indomethacin + PGF2α treated ovaries. Ovaries treated in perfusion with PGF2α alone had very low steroid levels compared to the ovaries treated with LH.
This study confirms that indomethacin blocks ovulation in the perfused rabbit ovary and that this blockade can be overcome by exogenous PGF2α. Indomethacin and PG-treatments after ovulation induction did not affect ovarian steroidogenesis. Furthermore, while PGF2α was able to induce ovulations in these perfused oestrous ovaries in the absence of LH, it did not stimulate steroidogenesis.
Thyrotrophin and growth hormone secretion and cell morphology in hypothyroid pituitary cells cultured on a natural extracellular matrix
Authors: Spira O. , Vlodavsky I. , Ulmansky R. , Atzmon R. , Fuks Z. , Gordon A. , Gross J. 
Published: December 2008

Abstract. Hypothyroid rat pituitary cells were cultured on an extracellular matrix (ECM) produced by corneal endothelial cells. ECM markedly affected the following parameters.
Cell attachment, spreading and proliferation were improved, resulting in a more rapid formation of confluent cell monolayers. In the presence of ECM the production of both thyrotrophin (TSH) and growth hormone (GH) was larger than in its absence. Immunofluorescence studies revealed that 20% of the cells in these monolayers were thyrotrophs; consequently, TSH content was higher while GH level was lower than in control cultures of euthyroid pituitaries. These data suggest that the in vivo physiological differences are maintained by the conditions of the culture. ECM enabled the response of both the somatotrophs and the thyrotrophs to thyrotrophin releasing hormone (TRH) and the cells remained responsive for at least 10 days. Maximal stimulation (1.3- to 6-fold) was obtained with 14 nm of TRH. In the absence of ECM the cells failed to respond to TRH. Cell morphology was examined by scanning electron microscopy (SEM). Cells grown on ECM were characteristically epithelial, whereas those cultured on plastic plates had a fibroblast-like appearance. Four types of cells were identified in the epithelial cell monolayers by the appearance of their surface. TRH induced a 2-fold increase in the number of cells covered with microvilli and a corresponding decrease in the number of smooth surfaced cells. This suggests that hormone secretion is associated with the formation of microvilli.
Differential effects of a dopaminergic drug (piribedil) on pituitary hormone release in normal men and women
Authors: De Marinis Laura , Mancini Antonio , Calabrò Francesco , Massari Michele , Torlontano Massimo , Barbarino Antonino 
Published: December 2008

Abstract. Six normal women, in the follicular phase of their menstrual cycle, and 6 normal men received orally 40, 60 and 100 mg doses of piribedil, a dopamine receptor agonist, or placebo. The effects of piribedil on anterior pituitary hormone release was evaluated. In normal women a dose-related decrease in Prl levels was observed, while in men the Prl decrement was not related to the dose employed. In women an increase in serum hGH occurred after administration of the lowest (40 mg) dose of piribedil. In normal men, on the contrary, a modest hGH stimulation was present after administration of all doses of the drug. No consistent changes in serum TSH, LH and FSH concentrations were observed and no side effects were reported.
The results from this study indicate that piribedil can exert differential effects on hypophyseal trophic hormone release and that these effects are sex-related. It is possible that the differences observed in men and women after the administration of piribedil are due to a different endogenous dopaminergic tone, induced by the different sexual steroid environment.