bluuebunny/crossref_metadata_2025_split huggingface dataset:
IN VITRO STUDIES ON COLLAGEN METABOLISM IN METAPHYSEAL RAT BONE
Authors: Langeland Norvald , Teig Vigdis 
Published: December 2008

ABSTRACT
Oestradiol-17β has been administered to hypophysectomized/castrated and to thyro-parathyroidectomized/castrated young mature female rats. Treatment with oestradiol-17β 5 μg/day per animal, was continued for 3 weeks. Bone pieces from tibia/femur metaphyses were incubated in vitro for 3 h in order to establish the bone collagen synthesis and resorption rates. The results were compared to results from a previous study on castrated female rats with intact hypophysis, thyroid and parathyroid glands.
Bone from the thyro-parathyroidectomized/castrated rats treated with oestradiol-17β had a significantly reduced collagen resorption rate in vitro as compared to their paired controls. This is a result consistent with that of castrated female rats with intact thyroid and parathyroid glands treated with oestradiol.
Oestradiol-17β had no detectable effect upon collagen metabolism in the hypophysectomized/castrated rats.
It is concluded that the effect of oestradiol on bone resorption is not exerted via the parathyroid glands or parathyroid hormone. The possibility that oestrogens may act on bone via the hypophysis is discussed.
SUPPRESSIVE EFFECT OF L-DOPA ON HUMAN PROLACTIN RELEASE DURING SLEEP
Authors: Chihara Kazuo , Kato Yuzuru , Maeda Kiyoshi , Ohgo Shozo , Imura Hiroo 
Published: December 2008

ABSTRACT
Immunoreactive plasma human prolactin (HPr) and human growth hormone (HGH) concentrations were measured in six normal young men with polygraphic sleep monitoring during normal sleep and during sleep in which 1-dihydroxyphenylalanine (1-DOPA) was infused intravenously at a rate of 0.8 to 1.0 mg/min. The intravenous infusion of 1-DOPA significantly suppressed the episodic release of HPr during sleep and the occurrence of rapid eye movement (REM) sleep. However, HGH release during sleep was not remarkably influenced by 1-DOPA.
These results suggest that central catecholaminergic neural mechanisms are related to both sleep-related HPr release and REM sleep, but do not play an important role in sleep-related HGH release.
SECOND ANTIBODY CHEMICALLY LINKED TO CELLULOSE FOR THE SEPARATION OF BOUND AND FREE HORMONE: AN IMPROVEMENT OVER SOLUBLE SECOND ANTIBODY IN GONADOTROPHIN RADIOIMMUNOASSAY
Authors: Koninckx Ph. , Bouillon R. , De Moor P. 
Published: December 2008

ABSTRACT
Coupling the second antibody to a solid pase (DASP) was found to be a definite improvement over the classical technique of soluble second antibody (DA) separation of bound and free hormone in the radioimmunoassays of gonadotrophins in plasma or in serum.
The duration (2.5 to 7.5 min) and the pH (10.5 to 12.5) of the cyanogen bromide activation of microcristalline cellulose did not affect the coupling capacity or the immunoreactivity of the second antibody, nor did it augment aspecific adsorption of free gonadotrophin on the cellulose matrix. Precision of duplicates was comparable for both methods but the accuracy and the detection limit of the solid phase system were higher due to a better separation of bound and free hormone, to the lower blank value and to the absence of aspecific interference of protein concentration.
Cost was lower since much less second antibody was needed in the solid phase system than in the soluble system and since the experimental procedures were simplified by the absence of prozoning effect and the solid nature of the cellulose matrix.
BINDING OF L-TRIIODOTHYRONINE TO ISOLATED RAT LIVER AND KIDNEY NUCLEI UNDER VARIOUS CIRCUMSTANCES
Authors: Docter R. , Visser T. J. , Stinis J. T. , van den Hout-Goemaat N. L. , Hennemann G. 
Published: December 2008

ABSTRACT
Triiodothyronine (T3) is specifically bound by nuclei from rat liver and kidney. Binding of T3 at 37°C reaches its maximum at 30 min. In the presence of EDTA (to remove Mg2+) T3 binds to a class of binding sites with an estimated equilibrium association constant (Ka) of 3.3 × 1010 m−1 and a maximal binding capacity (MBC) of 3.8 fmol T3/100 μg DNA. In the presence of MgCl2 T3 binds to a second class of binding sites with an estimated Ka of 4.8 × 108 m−1 and a MBC of 123 fmol/100 μg DNA. Among the analogues tested, binding - relative to T3 - of D-T3, triiodothyroacetic acid and desamino-T3 is the same for both classes of binding sites, but relative affinity of thyroxine, D-T4, tetraiodothyroacetic acid and desamino-T4 is 2.5 to 6 times higher for the second class of binding sites than for the first class.
The presence of a cytosol binding protein is not a prerequisite for binding of T3 to the nucleus.
ACTION OF CYCLIC ADENOSINE 3′,5′ MONOPHOSPHATE ON L-14C-LEUCINE INCORPORATION IN A SYSTEM OF ROUGH MICROSOMES FROM BOVINE THYROID GLAND
Authors: Wägar Gustav 
Published: December 2008

ABSTRACT
The effect of cAMP and varying concentrations of potassium (18–72 mM) on the incorporation of L-14C-leucine into TCA-precipitable protein was studied in a cell-free system comprising rough thyroid microsomes. cAMP (2 mm) alone or in combination with theopylline increased the incorporation of leucine into ribosome-bound (after DOC treatment) and extra-vesicular material, but had no significant effect on the DOC-released intravesicular material. Increase of the K+ concentration from 18 mm to 72 mm affected the incorporation of leucine into the microsomal compartments in much the same way as cAMP did.
The effect of cAMP and potassium seems to be due in partly to enhanced activation of amino acids, since in a system of pH5 fraction and cell sap, both cAMP and K+ increased the incorporation of 14C-leucine into cold TCA-precipitable material. Experiments with 14C-leucyl-tRNA as a marker suggest that the effect of cAMP and K+ is a consequence not only of increased activation of amino acids, but also of increased binding of activated amino acyl-tRNA to ribosomes.
ENHANCED BILIARY THYROXINE EXCRETION IN RATS TREATED WITH PREGNENOLONE-16α-CARBONITRILE
Authors: Japundžić M. M. , Bastomsky C. H. , Japundžić I. P. 
Published: December 2008

ABSTRACT
Normal rats were treated with pregnenolone-16α-carbonitrile (PCN) 10 mg/100 g by stomach tube twice daily for 3 days. In these animals the biliary excretion of intravenously injected 125I-thyroxine (T4) was enhanced and the bile: plasma 125I ratio (B/P ratio) and the biliary clearance rate of plasma 125I-T4 was increased. Normal rats were treated with PCN for 3 days and homozygous Gunn rats for 13 days. In both groups PCN enhanced the bile flow and elevated the B/P ratios and the biliary clearance rate of plasma T4 following ip injection of 125I-T4 17 h previously. PCN-treatment had no effect on the fractions of biliary 125I present as T4-glucuronide, T4 and I− in either the normal or Gunn rats. Treatment with PCN for 10 days produced goitres in normal and Gunn rats and in normal rats elevated the serum TSH (bioassay) levels and the 17 h thyroid 131I uptake as well as the serum PB125I concentrations, without affecting stable PBI concentrations. These data indicated increased pituitary TSH release in response to increased peripheral metabolism of thyroid hormone; enhanced hormonal release from the thyroid kept pace with the accelerated peripheral loss.
DIFFERENCES IN ACTION OF LH AND FSH ON THE FORMATION OF CYCLIC AMP IN THE PREPUBERTAL RAT OVARY
Authors: Selstam Gunnar , Rosberg Sten , Liljekvist Jan , Grönquist Lena , Perklev Torsten , Ahrén Kurt 
Published: December 2008

ABSTRACT
The actions of LH (NIH-LH-B8) and FSH (NIH-FSH-S9) on the cyclic AMP (cAMP) system in ovaries of 23–24 day old rats have been analyzed. An intravenous injection of LH increased ovarian cAMP levels in vivo after only 20 seconds. Maximal cAMP levels were seen after 15 min. Addition of LH or FSH in vitro to the isolated ovaries produced dose dependent increases of cAMP in the tissue as well as in the incubation medium. Low concentrations of LH caused a release of cAMP into the incubation medium without any detectable change in the tissue levels. The levels of cAMP in the incubation media for all concentrations of FSH were lower than the tissue levels, whereas for LH the opposite was found. In time-course experiments where the concentrations of LH (10 μg/ml) and FSH (100 μg/ml) were chosen to give similar tissue levels of cAMP, the release of the cyclic nucleotide into the incubation medium was approximately 2–3 times greater for LH than for FSH at the time periods studied (5–240 min). When LH and FSH were tested together in high concentrations, their effects were additive. When the ovaries were first incubated with FSH for 120 min followed by an incubation with LH, the stimulatory effect of LH was considerably reduced. When the order of the incubations was reversed, however, LH did not change the response to FSH. The results show that both LH and FSH have intrinsic effects on the cAMP system in the prepubertal rat ovary, but that the effects of the two gonadotrophins are not identical.
HYPOTHALAMIC-PITUITARY-TESTICULAR SYSTEM AND ADRENOCORTICAL FUNCTION
Authors: Verjans H. L. , Eik-Nes K. B. 
Published: December 2008

ABSTRACT
Effect of intramuscular administration of ACTH or dexamethasone on blood serum levels of testosterone, LH and FSH was examined in intact and castrated, adult, male rats. Six IU ACTH or 1 mg dexamethasone were given daily for 7 days. Corticotrophin treatment had no influence on circulating testosterone, LH and FSH in intact or castrated male rats. Dexamethasone administration resulted in a slight elevation of serum FSH in intact animals but not in castrates. LH and testosterone remained normal in both intact and castrated animals injected with dexamethasone. Under our conditions of study the secretions from the adrenal gland appear to be insignificant for the regulation of pituitary secretion of gonadotrophins in the male rat.
PRE-OPERATIVE LOCALIZATION OF HYPERFUNCTIONING PARATHYROID TISSUE BY PARATHYROID SCINTIGRAPHY
Authors: Burckhardt P. , Bischof-Delaloye A. , Ruedi B. , Delaloye B. 
Published: December 2008

ABSTRACT
In 22 patients who underwent surgery suspected of primary hyperparathyroidism, the surgical findings were compared with the results obtained by pre-operative parathyroid scanning and biochemical screening. Thirteen of 15 parathyroid adenomas were localized by pre-operative scanning, but in five of them a false positive focus was also described. The technique was less useful in primary hyperplasia. Comparable results were reported by other investigators. In both instances the best results were obtained in patients with high parathyroid activity as measured by plasma calcium, plasma alkaline phosphatase and tubular reabsorption of phosphorus (TRP). Parathyroid scintigraphy was especially helpful in the presence of ectopic adenomas and in patients who had undergone previous parathyroid surgery. Unfortunately, the possibility of false positive results makes it unreliable for the diagnosis of primary hyperparathyroidism.
FREE CORTISOL IN OBESITY; EFFECT OF FASTING
Authors: Galvão-Teles A. , Graves Linda , Burke C. W. , Fotherby K. , Fraser Russell 
Published: December 2008

ABSTRACT
Plasma and urinary corticosteroids were measured in 13 obese subjects before and after high and low protein diets, and after fasting. During isocaloric high and low protein diets, urinary 17-oxogenic steroids and to a lesser extent urinary free cortisol excretion rose and fell in parallel with protein intake. Plasma unbound cortisol levels were not much changed by high or low protein intake.
However, during 7 to 11 days total fasting, there was a highly significant rise in plasma unbound cortisol at 24.00. A smaller rise occurred at 09.00. The overall effect was a considerable diminution of the day-night variation of plasma unbound cortisol levels during fasting, and a rise in prevailing unbound cortisol levels and urinary free cortisol excretion. In 3 subjects tested these changes were reversed immediately by glucose re-feeding.
PLASMA STEROID AND PROTEIN HORMONE CONCENTRATIONS IN PATIENTS WITH PROSTATIC CARCINOMA, BEFORE AND DURING OESTROGEN THERAPY
Authors: Harper M. E. , Peeling W. B. , Cowley T. , Brownsey B. G. , Phillips M. E. A. , Groom G. , Fahmy D. R. , Griffiths K. 
Published: December 2008

ABSTRACT
Plasma testosterone, androstenedione, oestradiol-17β, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were not significantly different in patients with prostatic cancer, with benign prostatic hyperplasia or in patients without prostatic disease. Plasma prolactin concentrations were significantly lower in the patients with benign disease than those with prostatic carcinoma. Endocrine therapy in the form of stilboestrol administration significantly decreased plasma levels of testosterone, oestradiol-17β, FSH and LH within 7 days of the treatment. After 7 days therapy prolactin levels increased significantly in all patients studied. Changes in growth hormone concentrations were more varied in response to stilboestrol, being elevated in several patients and remaining unchanged in others. Treatment of a few prostatic carcinoma patients who were receiving stilboestrol therapy with CB154, an inhibitor of prolactin secretion, brought an immediate decrease in prolactin levels which was sustained. Plasma testosterone, androstenedione and growth hormone were unchanged in these patients but a significant decrease in plasma oestradiol-17β was noted in two patients during CB154 administration.
INHIBITION OF THYROGLOBULIN BIOSYNTHESIS AND DEGRADATION BY EXCESS IODIDE. SYNERGISM WITH LITHIUM
Authors: Radvila A. , Roost R. , Bürgi H. , Kohler H. , Studer H. 
Published: December 2008

ABSTRACT
Lithium and excess iodide inhibit the release of thyroid hormone from preformed stores. We thus tested the hypothesis that this was due to an inhibition of thyroglobulin breakdown. Rats were pre-treated with propylthiouracil (PTU) for 3 weeks in order to deplete their thyroids of thyroglobulin. While the PTU was continued, lithium chloride (0.25 mEq./100 g weight) or potassium iodide (3 mg per rat) were injected every 12 h for 3 days. Thereafter the thyroglobulin content in thyroid gland homogenates was measured. PTU pre-treatment lowered the thyroglobulin content from 4.21 to 0.22 mg/100 mg gland. Lithium caused a marked re-accumulation of thyroglobulin to 0.60 mg/100 mg within 3 days. While iodide alone had only a borderline effect, it markedly potentiated the action of lithium and a combination of the two drugs increased the thyroglobulin content to 1.04 mg/100 mg.
Thyroxine was injected into similarly pre-treated animals to suppress secretion of thyrotrophic hormone. This markedly inhibited the proteolysis of thyroglobulin and 1.3 mg/100 mg gland accumulated after 3 days. Excess iodide, given in addition to thyroxine, decreased the amount of thyroglobulin accumulated to 0.75 mg/100 mg gland. To study whether this could be explained by an inhibitory action of iodide on thyroglobulin biosynthesis, thyroid glands from animals treated with excess iodide were incubated in vitro in the presence of 0.2 mm iodide for 3 h. Iodide decreased the incorporation of radioactive leucine into total thyroidal protein and into thyroglobulin by 25 and 35 % respectively. Iodide did not inhibit protein synthesis in the kidney, liver or muscle tissue. Thus, large doses of iodide selectively inhibit thyroglobulin biosynthesis.
A TRANSIENT RISE OF HORMONE SECRETION: A RESPONSE OF THE STIMULATED RAT THYROID GLAND TO SMALL INCREMENTS OF IODIDE SUPPLY
Authors: Studer H. , Bürgi H. , Kohler H. , García M. C. , de Escobar G. Morreale 
Published: December 2008

ABSTRACT
Small doses of iodide (2 times 3.2 μg at 12 h interval), below those capable of inducing Wolff-Chaikoff effect, were injected into rats kept on a moderately low iodine diet. By means of a 125I equilibration technique as well as by direct measurement of cold T4, it was demonstrated that the level of circulating PB125I (representing iodothyronines as confirmed by column chromatography) increased by a mean of 40% within 24 h following the first iodide injection. The serum TSH concentration (measured by radioimmunoassay) was simultaneously depressed.
Thus, in stimulated thyroid glands, a biologically significant fraction of an iodide load escapes autoregulatory control of iodothyronine synthesis. A small, transient increase of hormone release is likely to represent the physiological response of a normal gland to a sudden supplement of iodide supply. The ensuing depression of TSH secretion may be necessary for final adjustment of thyroid function. It is considered to be the last step in a cascade of mechanisms whose interaction keeps the thyroidal hormone output within narrow limits in the face of a fluctuating iodide supply. Failure of one or several of these mechanisms in the goitrous human gland could conceivable explain the phenomenon of "Jod Basedow".
EFFECT OF SOMATOSTATIN ON BASAL AND GLUCOSE INDUCED INSULIN RELEASE IN FIVE PATIENTS WITH HYPERINSULINAEMIA
Authors: Efendić S. , Lins P. E. , Sigurdsson G. , Ivemark B. , Granberg P. O. , Luft R. 
Published: December 2008

ABSTRACT
Somatostatin in a dose of 490 μg over 90 min inhibited basal insulin release in one subject with hyperplasia of the pancreatic islets and in two with benign insulin secreting adenomas. These three subjects also showed a marked insulin response to glucose infusion. No inhibitory effect of somatostatin was observed in two patients with benign insulinomas who demonstrated only a minor response to glucose. In the patient with islet hyperplasia and in one of the adenoma patients, who had an exaggerated insulin response to glucose (maximal response 10–30 times the basal insulin value), somatostatin also suppressed glucose induced insulin release. Our data suggest a beneficial therapeutic effect of somatostatin in patients with spontaneous hyperinsulinism with a pronounced insulin response to glucose.
REDUCTION OF 3-OXOSTEROIDS IN HUMAN LIVER MICROSOMES
Authors: Björkhem Ingemar , Einarsson Kurt , Hellers Göran , Wikvall Kjell 
Published: December 2008

ABSTRACT
The 3α- and 3β-reduction of the following steroids was studied in human liver microsomes: 5α-androstane-3,17-dione, 17β-hydroxy-5α-androstan-3-one, 5α-pregnane-3,20-dione, 5β-pregnane-3,20-dione, 3-oxo-5β-cholanoic acid and 7α-hydroxy-5α-cholestan-3-one. With NADH as cofactor there was a preferential 3α-reduction of the C19- and C21-3-oxo-steroids and a preferential 3β-reduction of the C24- and C27-3-oxo-steroids. Substitution of NADH with NADPH influenced reduction of the substrates in different ways, indicating the presence of several 3α- and 3β-hydroxysteroid dehydrogenases with different substrate specificity and specificity towards NADH and NADPH. Only small or insignificant sex differences could be observed in the reductions studied.
TRANSLATION OF AVIDIN mRNA FROM CHICK OVIDUCT IN THE OESTROUS MOUSE UTERUS
Authors: Tuohimaa Pentti , Soderling Eeva 
Published: December 2008

ABSTRACT
Oestrogen-primed immature chicks were injected with 5.0 mg of progesterone. Twenty hours after progesterone avidin mRNA was isolated and purified by a method including an antibody precipitation of the avidin polysomes, phenol extraction and nitrocellulose trapping. A water solution of mRNA (1 μg) with [14C]amino acids was instilled into the uterine horn of oestrous or dioestrous mice. Saline and [14C]amino acids were injected into the opposite control uterine horn. Avidin was assayed by an antibody method. A clear-cut avidin synthesis was found in the oestrous uterus, whereas the dioestrous showed only a slight avidin synthesis. This suggest that there are no absolute species-specific factors required at the translational level of uterine protein synthesis and that the mammalian uterus can translate foreign hormone-specific proteins at a rate dependent on the endogenous protein synthesis.
DIFFERENCES IN URINARY EXCRETION OF STEROID 21-DEOXYKETOLS BY WOMEN PREGNANT WITH A NORMAL OR AN ANENCEPHALIC FOETUS
Authors: Adejuwon C. A. , Heys R. F. , Oakey R. E. 
Published: December 2008

ABSTRACT
During late pregnancy the urinary excretion of steroid 21-deoxyketols, which contain the CH3-CO-C(OH)< side chain, was 1.16 ± 0.50 mg/24 h (mean ± sd n = 9). The mean excretion of these metabolites in 8 pregnancies with an anencephalic foetus showed a significant reduction (P < 0.01, t-test) to 0.42 ± 0.18 mg/24 h. Six untreated non-pregnant women and 7 taking oral contraceptives which contain oestrogen had steroid 21-deoxyketol excretions of 0.26 ± 0.09 mg/24 h and 0.19 ± 0.09 mg/24 h respectively.
These results imply that the adrenal of the normal foetus makes a contribution to the secretion of those steroids which are ultimately excreted by the mother as 21-deoxyketols.
DIMINISHED SENSITIVITY OF THE INSULIN RESPONSE TO GLUCOSE FOLLOWING GROWTH HORMONE INFUSION IN MAN
Authors: Adamson Ulf , Cerasi Erol 
Published: December 2008

ABSTRACT
The acute effect of growth hormone (GH) administration on the dose-kinetics of glucose-stimulated insulin release was investigated in eight healthy, non-obese male subjects. The glucose-insulin dose-response relationship in these subjects was established by performing glucose infusions at three different dose levels. In a second series of experiments, the glucose infusions were preceded by a 30 min infusion of GH (40 μg/kg body weight), terminated 60 min before administration of glucose. GH induced small but significant reductions in the basal levels of blood glucose and plasma insulin. The glucose tolerance (k-value) was diminished after GH at all glucose doses. Both the initial late phases of insulin response to glucose were impaired following GH treatment. This effect was most pronounced when the intermediary glucose dose (eliciting a blood glucose level around 300 mg/100 ml) was used. Thus, the insulinogenic index (whole period of stimulation) was reduced by GH to 88.9 ± 7.6, 60.4 ± 7.1 and 74.3 ± 11.0% of the respective controls when the smallest, the intermediate, and the largest glucose loads, respectively, were given.
The blood glucose-plasma insulin dose-response curves were shifted to the right of the control ones when glucose infusion was preceded by GH. These findings suggest that GH diminishes the sensitivity of the islet for the insulin releasing action of glucose.
Some possible mechanisms by which GH may modify insulin release are discussed.
STUDIES ON THE MECHANISM OF SOMATOSTATIN ACTION ON INSULIN RELEASE
Authors: Efendić S. , Claro A. , Luft R. 
Published: December 2008

ABSTRACT
In man, 3 μg per kg per 90 min of linear somatostatin significantly inhibited basal as well as arginine induced insulin and glucagon release. One μg per kg per 90 min of somatostatin significantly inhibited basal insulin release but not basal glucagon release or arginine induced insulin and glucagon release.
In the perfused rat pancreas, as little as one ng per ml of perfusate of somatostatin significantly inhibited arginine induced insulin but not glucagon release, while 10 ng per ml of somatostatin by more than 50 per cent reduced the effect of arginine on insulin and glucagon release. Thus, linear somatostatin seemed to be a slightly more potent inhibitor of insulin than of glucagon release in man and in the perfused rat pancreas.