bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE EFFECT OF THYROTROPHIN RELEASING HORMONE ON PITUITARY AND THYROID FUNCTION IN PRE- AND POST-NATAL LAMBS
Authors: Wallace A. L. C. , Nancarrow C. D. , Evison B. M. , Radford H. M. 
Published: December 2008

ABSTRACT
Thyrotrophin releasing hormone (TRH, 50 μg) was injected into chronically catheterized foetuses at various ages from 107 days gestation and into lambs up to 13 days post-partum. Changes in the concentrations of TSH, prolactin, T3 and T4 in plasma were measured by radioimmunoassay.
The initial concentration of TSH (1.2 ± 0.2, sem, ng/ml) and its increase in response to TRH was similar at all foetal ages tested. However, both pre-injection concentrations of prolactin in plasma and the magnitude of the response to TRH increased with foetal age. The responses in lambs up to 13 days old were greater than those in the foetuses.
The concentration of T4 was 6.3 μg/100 ml plasma in a 107 day-old foetus This had doubled by 128 days but declined again towards parturition. After TRH injection plasma T4 concentration increased in lambs, but showed little or no change in 113 and 137 day-old foetuses.
The concentration of T3 increased from 4–5 ng/100 ml plasma in 110–116 day-old foetuses to 40 ng/100 ml just prior to parturition. Values were high in the young lambs (362 ± 79 ng/ml) but declined with increasing age. There was no response to TRH up to 130 days gestation. A small response was obtained in a 137 day-old foetus while the concentration of T3 rose from 37 to 90 ng/100 ml in the 144 day-old foetus.
Injection of luteinizing hormone releasing hormone in quantities ranging from 25 to 150 μg caused no changes in circulating levels of TSH and prolactin.
It is concluded that although the foetal pituitary can respond to TRH by at least 107 days gestation, its maturity in relation to prolactin synthesis and release develops gradually, but most rapidly over the last 10 days of gestation. In comparison, the pituitary-thyroid system, known to be functioning before 107 days, may be insensitive to hypothalamic control. The evidence suggests that there is increased maturity of the thyroid gland with increasing foetal age, the concomitant rise in thyroid hormones initiating a negative feedback response.
TWO ABNORMALITIES OF GLUCOSE-INDUCED INSULIN SECRETION: DOSE-RESPONSE CHARACTERISTICS AND INSULIN SENSITIVITY
Authors: Turner R. C. , Harris E. , Ounsted M. , Ponsford C. 
Published: December 2008

ABSTRACT
To characterize the defect of insulin secretion in diabetes, the response to different iv glucose loads has been studied in women who have had gestational diabetes and are, by definition, latent diabetic (LD). Women who have produced a large-for-dates baby, but who were not known to have been diabetic (LFD), have been investigated to determine if they have abnormal metabolism. Both groups were found to have raised fasting plasma glucose concentrations. Only the LD had glucose intolerance, which was associated with a reduced first phase insulin response to all glucose loads with a decreased maximal secretory capacity (low V max). The LFD women appeared to include a distinct abnormality in which the β cells had decreased sensitivity to glucose (high Km), with diminished secretory response to small but normal response to large loads. Whereas the LD probably have disordered μ cell function, some of the LFD women may represent the upper end of the normal range of the glucose "set" of β cell function. Neither group had insulin resistance, as measured by the hypoglycaemic response to an iv insulin bolus. A woman who has produced a LFD, but who was not known to be diabetic, does not necessarily have a diabetic tendency.
INHIBITORY EFFECT OF SOMATOSTATIN ON INSULIN SECRETION DURING α-ADRENERGIC BLOCKADE IN THREE DIFFERENT SPECIES
Authors: Järhult Johannes , Ahrén Bo , Lundquist Ingmar 
Published: December 2008

ABSTRACT
It has recently been suggested from experiments in dogs that somatostatin suppresses insulin release via a stimulation of the inhibitory α-adrenoceptors of the pancreatic B-cell. The effect of somatostatin on insulin secretion during α-adrenergic blockade with phentolamine was therefore studied in three different species; the rat, the cat and the mouse.
It was found that somatostatin significantly depressed insulin release during α-adrenoceptor blockade in all three species. In the rat, infusion of somatostatin at a dose of 0.3 μg/kg/min decreased basal plasma insulin concentration by 92 %. In the presence of phentolamine, the same dose of somatostatin lowered plasma insulin by 85 %. In the cat, a similar infusion of somatostatin lowered basal plasma insulin concentration by 87 %, but its depressive effect during α-adrenergic blockade was comparatively less pronounced (68 %) than in the rat. In the mouse, a single iv injection of somatostatin induced a short-lasting depression of plasma insulin concentration during α-adrenergic blockade.
From these results it seems unlikely that somatostatin should inhibit insulin release simply by stimulation of α-adrenoceptors on the B-cell. It cannot be ruled out, however, that a more complex interaction exists between somatostatin and the sympatho-adrenal system with regard to the control of insulin secretion.
CHANGES IN PLASMA ALDOSTERONE FOLLOWING THE ADMINISTRATION OF VARIOUS COMBINATIONS OF STIMULI
Authors: Gaillard R. C. , Riondel A. , Merkelbach U. , Vallotton M. B. 
Published: December 2008

ABSTRACT
The effects on plasma aldosterone levels of combinations of the main factors involved in aldosterone regulation have been studied in normal young male subjects. These factors, namely K, angiotensin II and ACTH were studied using combinations of K+ with angiotensin II, K+ with ACTH, and angiotensin II with ACTH.
KC1 infused in amounts (5–10 mEq./h) insufficient to increase plasma aldosterone by itself was found to potentiate the aldosterone response to an infusion of angiotensin II (7 ng/kg/min) in 8 out of 13 subjects. The same amount of KCl was also found to increase the rise in plasma aldosterone following an infusion of ACTH (16 ng/kg/min).
When an angiotensin II infusion was superimposed on the last 2 h of a 4-h infusion of ACTH, a striking rise in plasma aldosterone was observed, which exceeded the values obtained by ACTH alone. Conversely, when an ACTH infusion was superimposed on the last 2 h of a 4-h angiotensin II infusion, a further increase of plasma aldosterone was again observed. Our data support the idea that changes in all the known stimuli of aldosterone secretion have to be taken into account when interpreting changes in plasma aldosterone. Thus KCl, infused at rates without effect on aldosterone when given alone, will increase aldosterone during angiotensin II or ACTH infusion. The data also demonstrate that no refractory period is observed when one stimulus is superimposed on a previous one.
PLASMA 1,25-DIHYDROXYVITAMIN D LEVELS IN PREGNANCY AND LACTATION
Authors: Lund Bjarne , Selnes Anders 
Published: December 2008

ABSTRACT
Plasma concentrations of 1,25-dihydroxyvitamin D (1,25–(OH)2D), serum prolactin and serum parathyroid hormone (PTH) were followed during pregnancy and lactation in 16 women.
High 1,25–(OH)2D was demonstrated in human pregnancy and lactation. A causative relationship between 1,25–(OH)2D and prolactin is discussed and a possible explanation of the mechanism of the augmented calcium absorption in human pregnancy and lactation is suggested.
ISOLATION, CHARACTERIZATION AND RADIOIMMUNOASSAY OF CORTICOSTEROID-BINDING GLOBULIN (CBG) IN HUMAN SERUM – CLINICAL SIGNIFICANCE AND COMPARISON TO THYROXINE-BINDING GLOBULIN (TBG)
Authors: Bernutz C. , Hänsle W. O. , Horn K. , Pickardt C. R. , Scriba P. C. , Fink E. , Kolb H. , Tschesche H. 
Published: December 2008

ABSTRACT
Isolation of the corticosteroid-binding globulin CBG was achieved by 5 chromatographical steps on cortisol Sepharose, QAE-Sephadex A-50, Con A-Sepharose and hydroxylapatite. The purity of the isolated CBG was demonstrated in polyacrylamide gel electrophoresis, SDS electrophoresis, immunodiffusion and ultracentrifugation. Microheterogeneity was shown in isoelectric focusing by 5 bands in the pH range of 3.7–4.2, which could be reduced to one major band after neuraminidase treatment. The equimolar binding of cortisol to CBG was demonstrated by binding studies. The association constant for cortisol was 2.8 × 108 m−1, for progesterone 1.7 × 106 m−1. From analytical ultracentrifugation, the molecular weight was calculated on 50 700; the sedimentation coefficient was 3.6 S, the partial specific volume 0.690 ml/g, the Stokes radius 38 Å and the frictional coefficient ratio 1.5.
A specific radioimmunoassay for CBG was established using the purified CBG for immunization, radioiodination and for calibration standards. The normal range of CBG levels in human serum was 2.4–4.4 mg/100 ml (mean ± 2 sd). Studies were performed to compare the levels of CBG and thyroxine-binding globulin (TBG). No sex differences but a significant biphasic age dependence were observed for both proteins. In pregnancy and under oestrogen treatment of women and men, CBG was demonstrated to be the more distinct indicator of oestrogenic activity as compared with TBG, whereas the sensitivity of TBG was more pronounced to supposedly antioestrogenic substances like Danazol, and in severe disease. No coincidence of genetic CBG and TBG deficiencies have been found so far.
SERUM LEVELS OF SOMATOMEDIN A AND GROWTH DURING LONG-TERM TREATMENT OF PATIENTS WITH PITUITARY DWARFISM WITH HUMAN GROWTH HORMONE
Authors: Takano Kazue , Hizuka Naomi , Shizume Kazuo , Hasumi Yoko 
Published: December 2008

ABSTRACT
Eighteen patients with pituitary dwarfism were treated for 1 7/12 to 6 years with human growth hormone (hGH) at a dose of 0.19–0.62 unit (U) per kg of body weight per week. The mean increment in height was 2.0 ± 0.4 and 8.8 ± 0.5 cm/year before and the first year after treatment of hGH, respectively.
A significant positive correlation was observed between serum levels of somatomedin A and growth rate, especially in children with bone age below 10 and a duration of treatment of less than one year (r = 0.66, P < 0.005). Long-term treatment with hGH was accompanied by a decreasing response. However, the serum levels of somatomedin A did not decrease significantly. Therefore, decreased growth increment in these situations was not due to decreased serum levels of somatomedin A.
A TSH SECRETING PITUITARY TUMOUR CAUSING HYPERTHYROIDISM: PRESENTATION OF A CASE AND REVIEW OF THE LITERATURE
Authors: Afrasiabi Ali , Valenta Lubomir , Gwinup Grant 
Published: December 2008

ABSTRACT
A 45 year old male with a 12 year history of mild hyperthyroidism and a pituitary tumour is presented. He had both clinical and laboratory evidence of hyperthyroidism and his serum TSH was persistently and markedly elevated. A TRH test resulted in no further rise in serum TSH. No evidence of pituitary or peripheral endocrine deficiencies existed and prolactin levels were normal. Craniotomy was performed and a pituitary adenoma was removed. On light microscopy, it was mostly composed of chromophobes. However, occasional granulated cells were observed, and on electron microscopy, most of the cells contained fine granules, which suggested possible thyrotroph origin of the tumour. One week post-operatively the patient's serum TSH returned to normal. Again, TRH produced no response in TSH. The patient became hypothyroid by clinical and laboratory findings and is currently on thyroid replacement therapy. The previously reported TSH secreting tumours associated with hyperthyroidism are reviewed.
EFFECTS OF THREE-DAY ORAL CHOLECYSTOGRAPHY ON SERUM IODOTHYRONINES AND TSH CONCENTRATIONS: COMPARISON OF THE EFFECTS AMONG SOME CHOLECYSTOGRAPHIC AGENTS AND THE EFFECTS OF IOPANOIC ACID ON THE PITUITARY-THYROID AXIS
Authors: Suzuki Hoji , Kadena Nariyuki , Takeuchi Keisuke , Nakagawa Shoichi 
Published: December 2008

ABSTRACT
The effects of repeated doses of oral cholecystographic agents on serum thyroxine (T4), 3,3′,5-triiodothyronine (T3), 3,3′,5′-triiodothyronine (rT3) and thyrotrophin (TSH) concentrations were studied in 37 euthyroid male subjects.
Iobenzamic acid, tyropanoic acid, iopanoic acid, and ipodate sodium, in a dosage of 3 g for 3 days, respectively, induced a significant decrease in serum T3 and an increase in rT3 within 24 h after the initial dose, followed by an increase in TSH and a slight increase in T4. The extent of the changes in rT3 varied between the agents, ipodate causing the greatest change, but without any relation to the changes in T3 or T4.
Responses of serum T4, T3, rT3 and TSH concentrations to exogenous thyrotrophin-releasing hormone (TRH) and bovine TSH were also studied before and after 3-day doses of iopanoic acid. In 11 subjects given iopanoic acid, the response of TSH to TRH (500 μg, iv) was increased but the T3 response was unchanged. A dose of TSH (10 U.S.P. units, im) caused a significant increase in serum T3 and a decrease in TSH concentrations in 5 subjects both before and after cholecystography.
It is thus suggested that in euthyroid subjects given multiple doses of oral cholecystographic agents, (1) the primary and consistent events are the reciprocal changes of serum T3 and rT3. although the extent of the changes is not coordinately reciprocal; (2) the responsiveness of the pituitary thyrotrophs and thyroid to TRH is preserved; and (3) the high basal and TRH-induced TSH in the serum may be ascribed to the decrease in the serum T3 concentration.
SOLUBILIZATION AND PARTIAL CHARACTERIZATION OF THYROID MEMBRANE TSH BINDING PROTEINS
Authors: Czarnocka B. , Nauman J. , Adler G. , Kiełczyński W. 
Published: December 2008

ABSTRACT
Crude plasma membranes obtained from bovine thyroids were found to possess one class of high affinity, low capacity binding sites for TSH with average association constant (Ka) of 1.301 × 109 m−1 and maximal capacity 8.76 × 10−10 m/mg of protein.
Treatment of crude membranes fraction with 0.1 % Triton X-100 and the subsequent sonication in ultrasonic disintegrator resulted in solubilization of membranes proteins with mean recovery of 40.0 ± 6.2 %. Soluble proteins retained the property to bind [125I]TSH, but the binding of the hormone was decreased.
The removal of the detergent from the solubilizate by gel filtration on Sephadex LH-20 increased the binding of TSH well above that demonstrated for crude thyroid membranes.
The chromatography of soluble proteins on Ultrogel AcA-44 revealed the presence of two TSH binding proteins, one with the molecular weight (m.w.) above 130 000 daltons and the other with the m.w. approximately 30 000 daltons.
The electrofocusing of solubilizate on Ampholine resulted in two protein peaks, one at pH 4.0–4.1 and the other at pH 4.4–4.6. The latter peak was shown to bind [125I]TSH specifically.
The present results have confirmed the heterogeneous character of solubilized TSH receptor preparation and have shown that the hormone binding sites belong to acid proteins.
INTERACTION OF SYNTHETIC PROGESTAGENS WITH RENAL MINERALOCORTICOID RECEPTORS
Authors: Wambach G. , Higgins J. R. , Kern D. C. , Kaufmann W. 
Published: December 2008

ABSTRACT
Progesterone increases urinary sodium excretion at least in part by competition for renal mineralocorticoid receptors. In contrast, synthetic progestagens do not increase sodium excretion or even cause a slight sodium retention. We therefore compared the ability of progesterone and 12 progesterone like compounds to displace [3H] aldosterone from binding at cytoplasmic mineralocorticoid receptors in rat kidney. All synthetic progesteronelike steroids were less active than progesterone in competing with [3H]aldosterone for the receptor binding: progesterone 100 %, 11β-OH progesterone 50 %, 17 a OH-progesterone 24 % and 16 α-methylprogesterone 3 %. Derivates of 17 α OH-progesterone (medrogestone 5 %, dydrogestone 4 %, medroxy progesterone-acetate 2 % and chlormadinone-acetate 0.5 %) were more potent than 19-nor-testosterone derivates: ethisterone 1 %, norethisterone < 1 %, norethindrone < 1 %, norethylnodrel < 1 %, and ethynodiol-diacetate < 1 %. The decreased affinity of synthetic progestins for mineralocorticoid receptors explains in part the lack of natriuretic activity of these compounds.
STUDIES ON A PROTEIN SYNTHESIS DEPENDENT STEP IN LH RELEASE BY LH-RH
Authors: de Koning J. , van Dieten J. A. M. J. , Tijssen A. M. I. , van Rees G. P. 
Published: December 2008

ABSTRACT
The hypothesis that LH-RH induces LH release partly through a protein synthesis dependent step (protein factor) was further investigated using two different experimental designs.
First, during incubation of pituitary glands of intact dioestrous female rats with a maximally active concentration of LH-RH, the inhibitor of protein synthesis cycloheximide was added at various times after the beginning of the incubation. The results show that it takes a relatively long time, i.e. more than 1 h of exposure to LH-RH before the amount of the protein factor has increased sufficiently to allow a maximal LH secretion.
Secondly, LH-RH was injected iv after which the protein factor was assayed by incubating the pituitary glands with a maximally active concentration of LH-RH in the presence of cycloheximide and measuring LH release in vitro. It was found that 1 h after the injection sufficient protein factor was present to permit an elevated response to LH-RH. This response could be suppressed by injecting cycloheximide prior to LH-RH. When the interval between injection of LH-RH and beginning of the incubation was increased to 2 h, LH release in vitro decreased again. However, ovariectomy immediately before LH-RH injection resulted in maintenance of the elevated response to LH-RH in vitro, indicating a role of the ovaries in this phenomenon.
THE EFFECT OF RITODRINE ON CARBOHYDRATE AND LIPID METABOLISM IN NORMAL AND DIABETIC PREGNANT WOMEN
Authors: Lenz Suzan , Kühl Claus , Wang Palle , Mølsted-Pedersen Lars , Orskov Hans , Faber Ole K. 
Published: December 2008

ABSTRACT
The metabolic effects of a one hour intravenous infusion of the β-2-receptor stimulating drug ritodrine were studied in seven normal pregnant women, three White class A pregnant diabetics and eight White class B-D pregnant diabetics.
During ritodrine infusion all subjects in the three groups exhibited increases in plasma glucose (1.0, 1.6 and 2.1 mmol/l respectively), free fatty acids (360, 850 and 1150 μmol/l), lactate (0.43, 0.80 and 0.86 mmol/l) and β-hydroxybutyrate and decreases in standard bicarbonate. The rise in plasma glucose, free fatty acids and lactate was more pronounced in insulin treated diabetic. The rises in β-hydroxybutyrate and decreases in standard bicarbonate were of the same magnitude in all three groups. Plasma potassium fell in all subjects, whereas no detectable changes in plasma sodium were observed.
The endocrine pancreatic function was assessed by measuring plasma insulin (White class A and normals), C-peptide (White class B-D) and glucagon (all subjects). Plasma insulin increased in normals (22 μIU/ml) and White class A diabetics (33 μIU/ml), whereas plasma C-peptide of the insulin treated patients (White class B-D) were below measurable concentrations. Plasma glucagon and cortisol concentrations were not influenced by ritodrine.
The results suggest that the diabetogenic changes induced by ritodrine are augmented with the severity of diabetes but not ascribable to a diabetes-like change in the function of the endocrine pancreas.
SOLUBILIZATION OF THYROXINE-5′-DEIODINASE ACTIVITY FROM RAT LIVER MICROSOME FRACTION
Authors: Takaishi Masaru , Shimizu Taeko , Shishiba Yoshimasa 
Published: December 2008

ABSTRACT
The greater part of T3 is converted from T4 in liver or kidney. The majority of this activity exists in microsomal fraction. In the present study, we investigated whether this activity can be solubilized from rat liver microsomal pellet with various concentrations of deoxycholate (DOC). The extent of solubilization was compared with that of protein, rotenone insensitive NADH cytochrome c reductase or NADH cytochrome b5 reductase, which have been shown to associate with microsomal membrane rather than luminar contents. When 0.05 % of DOC which was capable of releasing luminar contents of microsomal vesicles was applied to microsomal suspension, only a limited part of NADH cytochrome b5 reductase, rotenone insensitive NADH cytochrome c reductase or T4-5′-deiodinase activity was solubilized. When the concentration of DOC was increased to 0.125 %, 41 % of T4-5′-deiodinase activity was solubilized. Solubilization of protein, NADH cytochrome b5 reductase or rotenone insensitive NADH cytochrome c reductase was increased abruptly to 66 %, 58 % or 63%, respectively. The highest specific activity was obtained at 0.125% DOC. These results suggest that the T4-5′-deiodinase is associated with microsomal membrane instead of luminar contents.
RESPONSES OF ALDOSTERONE-PRODUCING ADENOMAS TO ACTH AND ANGIOTENSINS
Authors: Saruta Takao , Okuno Tetsuji , Eguchi Toyohisa , Nakamura Ryuichi , Saito Ikuo , Kondo Kazuoki , Oka Masatsugu , Matsuki Shun 
Published: December 2008

ABSTRACT
To elucidate the control mechanism of aldosterone production in primary aldosteronism, in vivo and in vitro studies were done in 7 patients with aldosterone-producing adenomas.
In the in vivo study, plasma aldosterone was stimulated more significantly by synthetic ACTH than by angiotensin II or furosemide. Diurnal variations of plasma aldosterone, which were studied in 4 patients, were similar to those seen in normal controls. In agreement with the results in the in vivo study, the in vitro study also revealed ACTH stimulated aldosterone and deoxycorticosterone (DOC) from the adenoma more markedly than angiotensin II or III. There was no adenoma which was more sensitive to angiotensin II or III than to ACTH. From these results it is considered that changes in plasma aldosterone induced by the exogenous administration of angiotensin II or ACTH in patients with aldosterone-producing adenoma are mainly based on changes in aldosterone production in the adenoma. Furthermore, in patients with an aldosterone-producing adenoma in whom diurnal variations of plasma aldosterone similar to those in normal subjects are observed, responses of aldosterone to angiotensin II are supposed to be less than those to ACTH.
Repetitive intravenous TRH-stimulations at short intervals in euthyroid and hypothyroid subjects
Authors: Ahuja S. , Baumgarten S. , Oeff K. 
Published: December 2008

Abstract.
In 17 euthyroid normal volunteers and 17 hypothyroid patients, serum concentrations of TSH, T3 and T4 were measured after multiple stimulations with TRH. All subjects received 6 TRH-injections (200 μg iv) at intervals of 2 h. Three euthyroid normal volunteers were stimulated 12 times with TRH in the same way.
The TSH response (ΔTSH) was significantly decreased (P<0.01) after the 4th injection, and after the 5th of 6th stimulation, it was significantly raised (P<0.02) compared with the 4th. In the case of the 12-fold stimulations, the ΔTSH also rose after the 9th or 10th injection compared with the response after the 8th of 9th.
In 5 of the 17 normals, the increase in ΔTSH observed after the 5th or 6th TRH-injection was greater than the ΔTSH after the first stimlation.
Serum T3 and T4 levels rose already after the first TRH-stimulation (P<0.01) and remained at these increased levels thereafter.
The hypothyroid patients also showed initial decrease of ΔTSH (P<0.01). The increase of the TSH-response to TRH, however, was observed after the 4th TRH-injection (P<0.05) rather than after the 5th or 6th, followed by another decrease of ΔTSH after the 5th stimulation (P = 0.02). In 11 of the 17 hypothyroid patients, there was a second increase of ΔTSH after the 6th TRH-stimulation. This second increase was greater than the first in 10 of the 11 subjects. Serum T3 and T4 levels in the hypothyroid subjects remained unchanged during the entire examination period.
From these results, it can be concluded that the cause for the TSH response pattern in TRH-stimulations repeated at brief intervals cannot be due to the feed-back of thyroid hormones, but rather to the activity of TSH-producing pituitary cells.