bluuebunny/crossref_metadata_2025_split huggingface dataset:
INSULIN EFFECTS ON CALCIUM, MAGNESIUM AND PHOSPHATE METABOLISM IN RATS
Authors: Mellerup Erling T. 
Published: December 2008

ABSTRACT
Serum calcium as well as serum magnesium increased after insulin administration to rats. The increase in serum calcuim was followed by a decrease, which did not occur in thyroid-parathyroidectomized animals. The increase in both serum calcium and magnesium may be secondary to a diminished uptake of calcium and magnesium into bone. On the other hand this may be secondary to a decreased uptake of phosphate into bone. The decreased uptake of phosphate into bone may be secondary to the decrease in serum phosphate, which is a well-known phenomenon after insulin administration.
In addition to all these indirect effects, insulin directly increased the uptake of magnesium into muscle and probably also the liver, thus counteracting the increase in serum magnesium.
INCREASED STEROID METABOLIC CLEARANCE RATE IN ANEPHRIC PATIENTS
Authors: Corvol P. , Bertagna X. , Bedrossian J. 
Published: December 2008

ABSTRACT
The control of plasma aldosterone level depends on the secretion rate and on the metabolic clearance rate (MCR) of the hormone. The rate of aldosterone metabolism was measured in 6 anephric patients in comparison with normal volunteers. Unexpected high aldosterone MCR's were found in the anephric patients: 2700 ± 265 1/24 h (M ± sem), as compared to the normals (1600 ± 57). Passive 45° tilting did not significantly change aldosterone MCR's in both the normal and anephric patients. This increase in aldosterone MCR might be explained by a high hepatic plasma flow due to a high cardiac output. The haemodynamic condition of these patients could also explain the high testosterone MCR found in 3 male anephric patients, although testosterone-oestradiol binding globulin was in the high normal male range.
URINARY FOLLICLE STIMULATING HORMONE CHORIONIC GONADOTROPHIN AND OESTROGENS DURING HUMAN PREGNANCY
Authors: Watanabe Noboru , Seki Mitsunori , Seki Katsuyoshi , Yoshihara Terufumi 
Published: December 2008

ABSTRACT
Concentrations of follicle stimulating hormone (FSH) and human chorionic gonadotrophin (HCG) were measured in randomly voided urine of 50 women during pregnancy by double antibody radioimmunoassay. Daily 24 h urine specimens were also collected once a week from 4 pregnant women from the early period of pregnancy up to delivery. In the 4 women, pregnancy was induced by the treatment with ovulatory agents. Urinary total oestrogens excretion as well as the FSH and HCG excretions were determined in the 24 h specimens. In the randomly voided urine, the concentration of FSH showed a tendency to increase progressively until term. The concentration of HCG was highest at weeks 9–12. Similar patterns of both the urinary FSH and HCG excretions were found in the serially collected 24 h specimens. However, continuous fluctuation in the FSH excretion was observed in two of the four cases followed throughout pregnancy. The urinary excretions of total oestrogens in 24 h specimens showed a relatively steady rise from week 16 and reached a peak before the onset of delivery. The excretion of total oestrogens as well as HCG showed a rapid fall after delivery.
STIMULATION BY STEROIDS AND AGE-DEPENDENT CHANGES OF L-CYSTINE ARYLAMIDASE ACTIVITY IN THE HYPOTHALAMUS OF THE RAT
Authors: Kuhl Herbert , Rosniatowski Christian , Bickel Martin , Taubert Hans-Dieter 
Published: December 2008

ABSTRACT
L-cystine arylamidase activity was found to be high in hypothalamic homogenates from 10 day old rats, and then to decrease significantly until sexual maturity was reached (P < 0.01). This enzyme activity could be stimulated by treating 10 to 35 day old male rats with 100 μg of testosterone. Contrary to this, L-cystine arylamidase activity could not be stimulated in female animals by the injection of 7 μg of ethinyl-oestradiol before Day 45 of life. These data are interpreted as meaning that the L-cystine arylamidase activity plays a rôle in the processes regulating sexual maturation.
THE EFFECT OF THYROTROPHIN RELEASING HORMONE ON THE RELEASE OF THYROTROPHIN AND OTHER PITUITARY HORMONES IN MAN UNDER BASAL CONDITIONS AND FOLLOWING ADRENERGIC BLOCKING AGENTS
Authors: Nilsson K. O. , Thorell J. I. , Hökfelt B. 
Published: December 2008

ABSTRACT
Studies were performed in nine healthy male volunteers to evaluate the effect of the iv injection of 200 μg of thyrotrophin releasing hormone (TRH) on the blood concentrations of various anterior pituitary hormones, thyroxine and cortisol before and following treatment with propranolol and phentolamine, respectively. The influence on the free thyroxine index was also studied.
In all subjects TRH was followed by an increase in plasma thyrotrophin (TSH) with a maximum 20–30 minutes after the injection. The increase in TSH was significantly less after treatment with phentolamine as compared to no treatment (P<0.05; paired t-test) and propranolol (P<0.02), respectively. Thus, our studies could indicate that adrenergic receptors are of importance for the TRH induced release of TSH.
The plasma concentration of thyroxine and the free thyroxine index both increased significantly after TRH under all conditions studied.
TRH induced no changes in the plasma levels of growth hormone, follicle stimulating hormone, luteinizing hormone and serum cortisol, indicating that TRH has a rather specific effect on the production of TSH. This specificity is not altered by either alpha- or beta-blocking agents.
ADRENAL CONTRIBUTION TO PLASMA OESTROGENS IN ADRENAL DISORDERS
Authors: Yuen Basil Ho , Kelch Robert P. , Jaffe Robert B. 
Published: December 2008

ABSTRACT
The concentrations of oestrone (Oe1) and oestradiol (Oe2) in adrenal venous and peripheral plasma (inferior vena cava, aorta and/or antecubital vein) were measured by radioimmunoassay in 8 patients in whom an adrenal disorder was suspected (group A) and 5 patients in whom an adrenal disorder was proven (group B). In group A, 6 patients had higher Oe1 concentrations in adrenal than in peripheral plasma, while 5 patients had higher Oe2 concentrations in adrenal venous plasma. In group B, in 3 of 4 patients with primary aldosteronism secondary to an adrenocortical adenoma, both Oe1 and Oe2 concentrations in the adrenal venous plasma from the side of the adenoma were greater than in peripheral plasma. A patient with Cushing's disease showed a similar gradient for Oe1 but not Oe2.
The results are consistent with the following conclusions: 1) Both Oe1 and Oe2 are secreted from the adrenal in neoplastic and non-neoplastic disorders in detectable but small amounts. 2) Estimates of maximal adrenal secretion rates in 3 male patients indicate that the adrenal contribution was less than 4 % (Oe1) and less than 2 % (Oe2), of reported blood production rates of oestrogens in normal men.
THE IN VITRO EFFECT OF PROGESTERONE AND OESTROGENS ON THE SPONTANEOUS AND OXYTOCIN-INDUCED ACTIVITY OF THE HUMAN MYOMETRIUM
Authors: Barnafi L. , Larraguibel R. 
Published: December 2008

ABSTRACT
The in vitro effect of progesterone and oestrogens on the spontaneous and oxytocin-induced activity of the pregnant and non-pregnant human myometrium was studied.
Oestrogens as well as progesterone blocked the spontaneous and oxytocininduced contractions 10–20 min after the steroids were added to the bath. The inhibitory effect was dose-dependent and reversible. Oestradiol-17β and diethylstilboestrol were approximately 10 times more active than progesterone.
The possible mechanism of action of oestrogens and progesterone are discussed.
THE INFLUENCE OF ETHANOL ON THE CONVERSION OF PREGNENOLONE TO PROGESTERONE BY HUMAN PLACENTAL MICROSOMES
Authors: Lübbert H. , Pollow K. , Wagner R. , Hammerstein J. 
Published: December 2008

ABSTRACT
The effects of ethanol on kinetic parameters of placental Δ5-3β-hydroxysteroid dehydrogenase were studied. In the presence of high pregnenolone concentrations (50 μm, [S] > Km) the microsomal enzyme preparation exhibited an almost linear increase in activity as the ethanol concentration in the medium was raised from 2.5 to 15 % (v/v). At lower substrate concentrations ([S] << Km) ethanol caused inhibition. Other effects of ethanol were: linearity of product formation with time was prolonged; the maximal velocity was markedly increased; the Km for pregnenolone slightly decreased with increasing ethanol concentrations (2.5 to 10 %, v/v) whereas the Km for NAD remained the same. The pH and temperature optima of the reaction were unaffected by ethanol. Other organic solvents caused similar effects.
PITUITARY-GONADAL INTERRELATIONSHIPS IN PUBERTAL FEMALE SUBJECTS
Authors: Adamopoulos D. A. , Loraine J. A. , Lunn S. F. , Mackay M. A. , Forfar J. O. 
Published: December 2008

ABSTRACT
Hormone assays in urine were conducted serially in four girls for 28 to 78 days each year for a period of four or five years. Assays of the three classical oestrogens and pregnanediol were made throughout this time; total gonadotrophins were estimated during the first two years and FSH and/or LH in subsequent years. Oestrogen output rose gradually throughout, evidence of variation in hormonal activity being noted from the second year onwards. In two of the girls who menstruated in the fourth year, the pattern of oestrogen excretion was similar to that of adult women during reproductive life. Pregnanediol output was generally low, tended to rise with increasing age, and from the second year onwards levels fluctuated. Ovulation, as judged by pregnanediol assays, occurred in two out of the nine cycles studied. Total gonadotrophic activity was low in the first year and rose in the second. In the third year FSH output was at the lower end of the range of values occurring in young normally menstruating women and was within this range during the fifth year. LH activity was low when first estimated, rose slightly in the fourth year, and showed a typical adult pattern, including a midcycle peak, in the fifth. The investigation demonstrated a progressive rise in steroid and gonadotrophin output in pubertal female subjects as they increased in stature, developed secondary sex characteristics and approached the menarche; the increase was associated with marked fluctuations in hormonal activity well in advance of the first menstrual bleeding. The physiological significance of these bleedings is discussed, and it is emphasised that the study as a whole provides a useful framework for the investigation of pathological conditions occurring at or about the time of puberty.
EFFECT OF IODIDE AND THYROTROPHIN ON IN VITRO 14C-AMINO ACID INCORPORATION INTO RAT THYROID PROTEINS
Authors: Valenta Lubomir J. 
Published: December 2008

ABSTRACT
Thyroid lobes from rats on normal (NID) or low iodine (LID) intake were incubated for 4 hours in vitro in the presence of 14C-amino acids. The 14C-amino acid incorporation into thyroid protein was significantly higher in thyroids from LID than from NID fed rats, 7.82 ± 1.01 % (mean ± sd) of total radioactivity of the incubation mixture per 100 mg tissue compared to 3.74 ± 0.60 % respectively. Thyrotrophin (TSH) in vitro did not influence the 14C-amino acid incorporation. Iodide in concentration 10−7 m and higher decreased 14C-radioactivity incorporation into protein by 19.40 ± 3.06 and 26.59 ± 4.06 % of the control value for NID and LID rats respectively. This effect of iodide did not depend on iodine organification and was not influenced by the changes of free amino acids pool. There were no significant differences in the relative concentration of 14C-labelled thyroglobulin and total 14C-thyroid protein. Differential fragility demonstrable by unfolding or dissociation was observed between different classes of thyroglobulin. The fragility was increasing from the old non-labelled molecules to newly iodinated and newly synthesized ones. It is concluded that iodide has a direct intrathyroidal blocking effect on thyroid protein synthesis which may contribute to its antigoitrogenic action. The lack of in vitro stimulation of protein synthesis by TSH remains unexplained.
THE EFFECTS OF CALCITONIN ON THE METABOLIC DISTURBANCES SURROUNDING WIDESPREAD BONY METASTASES
Authors: Parsons V. , Dalley V. , Brinkley D. , Davies C. , Vernon A. 
Published: December 2008

ABSTRACT
Seven patients with widespread bony metastases, with and without hypercalcaemia were given porcine or salmon calcitonin in an attempt to reduce that rate of progression of their disease, possibly to reduce pain and to accelerate healing during the course of other endocrine therapy. The latter included the administration of phosphate, steroids, androgens or oestrogens and hypophysectomy. Calcitonin effects were seen to be enhanced by simultaneous administration of phosphate and possibly antagonised by oestrogens. The metabolic changes that did occur, suggested that the rate of healing of metastatic bone disease was increased and the mechanisms of these changes are discussed.
CALCIUM AND STIMULUS-SECRETION COUPLING IN THE NEUROHYPOPHYSIS
Authors: Russell J. T. , Thorn N. A. 
Published: December 2008

ABSTRACT
Groups of 10 hemilobes of rat neurohypophyses were stimulated for 10 min in a medium containing 56 mm K+ or by application of a field current (20 Hz, 2 msec, 40 mA). Both stimulations resulted in a 5 to 8 fold increase in the release of vasopressin which was inhibited (in a dose-related manner) by addition to the medium of various blockers of calcium transport: LaCl3 (4 × 10−4, 4 × 10−3 m/l), prenylamine (2 × 10−5, 1 × 10−4 m/l) and D600, a verapamil derivative (4 × 10−6, 1 × 10−5, 2 × 10−5 m/l). Increasing the Ca2+ concentration in the medium to 14 mm abolished the inhibitory effect of D600. D600 also inhibited vasopressin release caused by introducing Ca2+ into a Ca2+-free medium during continued electrical stimulation.
Efflux of 45Ca2+ from neural hemilobes labelled during incubation in a 56 mm K+ containing medium was markedly increased during stimulation with a 56 mm K+ medium or electrical current. Lanthanum (4 × 10−3 m/) and D600 (2 × 10−5 m) inhibited this increased efflux as well as hormone release.
When the hemilobes had been pre-labelled in a medium with 4.8 mm K+, stimulation during efflux, by 56 mm K+ or electrical current, caused hormone release comparable to that seen after labelling in 56 mm K+, but with neither type of stimulation was there any significant increase in 45Ca2+ efflux.
These findings would appear to be in agreement with a hypothesis that very small amounts of Ca2+ enter the endings of the neurosecretory neurons on stimulation (thereafter possibly releasing intracellular calcium) and that calcium entry is essential in inducing hormone release. The uptake of calcium over the neurosecretory nerve membrane apparently has several of the characteristics shown for calcium entry on stimulation of the squid axon.
EFFECT OF AMINOPHYLLINE ON GROWTH HORMONE SECRETION IN MAN
Authors: Peracchi M. , Cavagnini F. , Pontiroli A. E. , Raggi U. , Malinverni A. , Pinto M. 
Published: December 2008

ABSTRACT
The effects of intravenously administered aminophylline on growth hormone (GH) secretion have been studied in sixteen normal subjects and four acromegalic patients.
Intravenous infusion of theophylline ethylenediamine 480 mg over a 30 min period did not alter the blood glucose and serum GH levels in six normal subjects but raised the plasma FFA by 88 %. By contrast, in four acromegalic patients theophylline administration resulted in a fall of the serum GH levels by 17.6–51.7 %, mean 36.5%. In ten normal subjects the infusion of the drug clearly blunted the GH response to insulin hypoglycaemia without modifying the decrease in blood glucose and plasma FFA induced by insulin: mean peak GH values decreased from 32.7 ± 3.39 to 21.4 ± 4.10 ng/ml (P < 0.025).
These data seem to indicate that theophylline has an overall inhibiting effect on the hypothalamic-hypophyseal axis for GH secretion.
HOMOLOGOUS RADIOIMMUNOASSAY OF THYROTROPHIN IN RAT PLASMA
Authors: David Kieffer J. , Weintraub Bruce D. , Baigelman Walter , Leeman Susan , Maloof Farahe 
Published: December 2008

ABSTRACT
An homologous radioimmunoassay (RIA) using the highly purified rat thyrotrophin (TSH) and anti-rat TSH recently made available by NIAMDD is described in detail.
Evidence that the assay measures TSH and only TSH includes the following:
Treatment of rats with TSH-releasing hormone (TRH) caused a significant increase (averaging 12-fold) and treatment with T4, a significant decrease (averaging 4.5-fold), in plasma TSH. Points for TSH standards and those for dilutions of plasma from TRH-treated rats fell on the same line, and regression lines calculated separately for standards and dilutions of plasma did not depart significantly from parallelism. At 14 days after gonadectomy of male rats, a time when plasma LH and FSH levels are known to be high, the assay showed no increase in plasma TSH. Moreover, reduction of plasma TSH levels by T4 was as great in gonadectomized rats as in controls. Assay of rat LH, rat FSH and rat prolactin, in 7 concentrations each, showed that cross-reaction averaged less than 1 % in all cases. Other workers have calculated values greater than 1 % for TSH contamination of rat LH and FSH. The slopes of regression lines for the 3 hormones tested for cross-reaction did not differ significantly from the slope for TSH standards. This result strengthens the hypothesis that the apparent slight cross-reactions are due to TSH contamination.
Findings for T4-treated rats and saline-treated controls show that the homologous RIA is more sensitive than previous, heterologous assays: In previous studies, plasma TSH levels of most or all of rats treated with T4 were not clearly greater than zero. By contrast, in the homologous RIA reported here, values for such rats did not overlap the range of the zero point on the one hand, nor the range for saline-treated controls on the other. Thus, distinct ranges were defined for both normal and low TSH levels. In view of the 1:20 final dilution of plasma during assay, it does not seem likely that non-specific effects of plasma were primarily responsible for the low TSH values of T4-treated rats.
Additionally, the useful range of the homologous assay (about 200-fold) is greater than that of earlier assays (about 70-fold, or less). Finally, the use of highly purified rat TSH for standards has avoided inconsistencies previously encountered with bovine TSH standards.
METABOLISM OF PREGNENOLONE AND PREGNENOLONE SULPHATE IN HUMAN FOETAL LIVER TISSUE IN VITRO
Authors: Huhtaniemi Ilpo 
Published: December 2008

ABSTRACT
The metabolism of pregnenolone and pregnenolone sulphate was studied in incubations with minced foetal liver tissue. In most of the incubations, non-radioactive substrates were used, and the identification and quantitative determination of the metabolites formed was carried out by gasliquid chromatography and gas chromatography – mass spectrometry. Both the free and sulphated substrates were extensively metabolized by the liver preparations, and with both substrates, the same enzyme activities were observed. Furthermore, active sulphate conjugation was seen with free pregnenolone. No sulphatase activity was observed, and the direct conversion of pregnenolone sulphate to 16α-hydroxypregnenolone sulphate was demonstrated in incubations with [7-3H]pregnenolone [35S]sulphate. The highest conversion rate with both substrates, about 25 %, was for 16α-hydroxylation. Other enzyme activities detected were 20α-reduction and 3β-hydroxy-5,16-pregnadien-20-one formation. In sulphate conjugation and 16α-hydroxylation a slight decrease was observed with advancing foetal age, while in the case of 20α-reduction, somewhat higher conversion rates were observed in older foetuses. In this respect, the only significant difference between the two substrates used was the more pronounced decrease in pregnenolone sulphate 16α-hydroxylation with increasing foetal age.
This study sheds more light on the biological significance of steroid sulphates as metabolic intermediates in the human foetus and further evidence for their direct conversion into other steroid sulphates was obtained. It is suggested that the foetal liver plays an active role in such conversions.
CELLULAR AND SUBCELLULAR LOCALIZATION OF 3H-OESTRADIOL IN THE OVIDUCT AND UTERUS OF THE NEONATAL RAT
Authors: Sheridan Peter J. , Sar Madhabananda , Stumpf Walter E. 
Published: December 2008

ABSTRACT
Two day old female rats were injected sc with 1.0 μg of 3H-oestradiol per 100 g body weight and killed 2 h later. Oviducts and uteri were removed, mounted on tissue holders, and frozen in liquefied propane. Four μm frozen sections were cut in a cryostat and mounted according to the dry-mount and thaw-mount autoradiographic procedures. The sections were exposed at –15°C for different periods of time, then photographically processed and stained with methyl green-pyronin. Radioactivity was found concentrated in nuclei of cells of the luminal epithelium in the uterus, but not in the oviduct, while cells of the connective tissue and muscularis showed nuclear concentration of radioactivity in both organs. Pretreatment with oestradiol inhibited the nuclear concentration of radioactivity, whereas pretreatment with 5α-dihydrotestosterone had no effect. It is concluded that both the uterus and oviduct of the neonatal rat have receptors for oestrogen as early as 2 days after birth.
BIOSYNTHESIS OF 3β,17β-DIHYDROXYANDROST-5-EN-16-ONE BY HEPATIC MICROSOMES FROM PREVIABLE AND ANENCEPHALIC HUMAN FOETUSES
Authors: Tabei Toru , Heinrichs W. LeRoy 
Published: December 2008

ABSTRACT
Hepatic microsomes from previable and anencephalic human foetuses incubated with 14C-dehydroepiandrosterone synthesize 16-keto-A5-diol in addition to 6 other metabolites. The rate of production of 16-keto-A5-diol (nmoles min−1mg−1) was greater than those to 16α-OH-DHA or A5-triol. Other products accounting for most of the remaining radioactivity were A5-diol, 7α- and 7β-OH-DHA, and 7-keto-DHA. Rates of 7α-hydroxylation were lower in liver from the anencephalic foetuses than from previable foetuses, but no qualitative differences appeared. These data demonstrate the capacity in vitro of human foetal liver for synthesizing 16-keto-A5-diol, an abundant steroid of umbilical cord blood and the physiologic precursor for 16-keto-oestradiol-17β, a major urinary oestrogen of human pregnancy.
THYROID PROTEINS AND HORMONE SYNTHESIS IN HUMAN THYROID CANCER
Authors: Thomas-Morvan Colette , Nataf Berthe , Tubiana Maurice 
Published: December 2008

ABSTRACT
Thyroid iodoproteins and hormone synthesis have been studied in vivo and in organ culture in 44 cases of thyroid cancer. In a few cases, Tg1) (17–19 S) is virtually absent; a portion of the light fractions (3–8 S), which seems to represent some precursors of Tg, incorporated in culture the 14C-amino acids.
In most of the cases, the solubility profiles, sedimentation patterns as well as electrophoretic migration of proteins were normal. The content of Tg and the concentration of stable iodine (127I) in Tg are less than that of "normal" tissues, and the deficiency in iodination appears to be more pronounced than the depression of the Tg synthesis. Most frequently the radioiodine uptake is very low and most of the iodine remains in the gland as iodide and MIT. In those tissues which organify radioiodine, it is incorporated into tyrosine molecules and is metabolized to the stage of iodothyronines (T4 + T3); there must then be little or no defect in coupling reactions. There is a linear relation between the concentration of stable iodine in Tg and the level of hormone synthesis, as we have found in "normal" gland and benign thyroid diseases. These results suggest that the overall disorder seen in thyroid cancer tissues appears to involve one of the initial steps of hormone synthesis. The very low mean iodination of Tg in these tissues suggests a great heterogeneity in the functional activity throughout the tumour.
TSH has a very variable effect on thyroid cancer tissues maintained in organ culture: in 46 % of the cases the hormone has no effect. In some instances TSH may significantly increase the incorporation of radioiodine into soluble iodoproteins, Tg as well as the albumin fraction.