bluuebunny/crossref_metadata_2025_split huggingface dataset:
A possible relationship between serum transferrin, growth hormone secretion and height velocity in children
Authors: Donnadieu M. , Schimpff R. M. , Garnier P. , Chaussain J. L. , Job J. C. 
Published: December 2008

Abstract.
Since transferrin (Tf) in vitro has a growth-promoting activity and is associated with NSILA properties, the aim of this work was to study in vivo the relationships between Tf, somatomedin activity (SM), growth hormone (GH) secretion, and height velocity in children. An iv infusion of ornithine hydrochloride was given to 23 controls; the induced rise of GH was accompanied by a simultaneous fall of SM (r = −0.711, P < 0.001) and was preceded by a fall of Tf (r = −0.610, P < 0.01). In 17 obese children SM was within the normal range, when Tf levels were higher and arginineinduced GH peaks lower than in the controls, and a negative correlation was found between Tf basal levels and GH peaks (r = −0.608, P < 0.01). In 9 children with confirmed hypopituitarism the Tf levels were significantly lower than in the controls. In 14 children with confirmed or suspected hypopituitarism a single im injection of hGH (6 mg) failed to induce Tf variations over 24 h. In 39 of these children the height velocity was significantly correlated with Tf basal levels (r = 0.701, P < 0.001). These data suggest that transferrin is involved in growth regulation, and that GH secretion is related to transferrin levels by a feed-back mechanism.
Effect of acute and repeated administration of gamma aminobutyric acid (GABA) on growth hormone and prolactin secretion in man
Authors: Cavagnini F. , Invitti C. , Pinto M. , Maraschini C. , Di Landro A. , Dubini A. , Marelli A. 
Published: December 2008

Abstract.
A single oral dose of 5 g gamma aminobutyric acid (GABA) was given to 19 subjects and serial venous blood samples were obtained before and 3 h after drug administration. A placebo was administered to 18 subjects who served as controls. GABA caused a significant elevation of plasma growth hormone levels (P < 0.001), but did not consistently alter plasma prolactin concentration since only 5 out of 15 subjects showed an increase of the hormone. Eight additional subjects were submitted to an insulin tolerance test before and after per os administration of 18 g GABA daily for 4 days. Protracted GABA treatment significantly blunted the response of growth hormone and enhanced that of prolactin to insulin hypoglycaemia (P < 0.01).
These results indicate that pharmacological doses of GABA affect growth hormone and prolactin secretion in man. The precise nature of GABA's effects as well as its mechanism of action remains to be clarified.
Serum somatomedin activity measured as sulphation factor in peripheral, hepatic and renal veins in normal mongrel dogs: Early effects of intravenous injection of growth hormone
Authors: Schimpff Rose-Marie , Donnadieu Marcel , Duval Michel , Leduc Brigitte 
Published: December 2008

Abstract.
The aim of this work was to study the early effects of an intravenous growth hormone (GH) injection on serum somatomedin (SM) activity in samples from peripheral (PV), hepatic (HV) and renal (RV) veins in dogs: 5 dogs were given one bovine growth hormone (bGH) injection, 1 dog was given 5 different doses of human growth hormone (hGH) and 6 control dogs were given saline.
In bGH-treated dogs, a significant increase of SM activity occurred in the three vessels without difference between vessels. An early paradoxical decrease of serum somatomedin activity appeared in the dogs given more than 1.15 IU/kg. In the dog given hGH, the response of SM activity was significantly related to the hGH dose in the PV and not in the other vessels.
These data seem to indicate that other sites than the liver and the kidney are involved in the production of GH-induced serum somatomedin activity. Following GH injection as well as in basal status. the liver may be implicated in the regulation of serum somatomedin activity.
On the development of pituitary responsiveness to LRH and the characteristics of pre-ovulatory LH-surges in the rat. Effect of oestradiol benzoate
Authors: Schuiling G. A. , Zürcher A. F. , Pols-Valkhof N. , Koiter T. R. 
Published: December 2008

Abstract.
Administration of oestradiol benzoate (OeB) on the second day of dioestrus of 5-day cyclic rats may advance ovulation by 24 h. The threshold dose of OeB necessary to achieve this effect varies with the time of administration. At 09.00 h, the 50% effective dose (ED-50) of OeB for advancing ovulation was 3.1 μg; at 17.00 h it was 31 μg. In the present study OeB was injected at either 09.00 or 17.00 h at doses about 3 times the corresponding ED-50's: 10 and 100 μg, respectively. Though both regimens of OeB administration resulted in advancement of ovulation, neither had more than a moderate effect on the development of pituitary responsiveness to LRH. In neither group could OeB-induced LH-surges be distinguished from "normal" 4-day rat-LH-surges and both differ from 5-day rat-LH-surges. It is concluded that (1) in the "Everett-model" OeB acts almost exclusively on the central nervous system; (2) the oestrogen-induced surge of LH is an all-or-none effect; and (3) there exists no relationship between the blood oestrogen concentrations and the characteristics of the induced LH-surges.
Effect of chronic intermittent immobilization stress on hypophyso-gonadal function of rats
Authors: Taché Y. , Ducharme J. R. , Charpenet G. , Haour F. , Saez J. , Collu R. 
Published: December 2008

Abstract.
The neuroendocrine mechanisms involved in chronic stress-induced testosterone (T) suppression have been evaluated in adult male rats. In intact animals, restraint applied 6 h daily for 6 days increased plasma corticosterone, decreased significantly T and Prl, and, to a lesser degree, LH levels. In adrenalectomized (adr-x) rats exposed to the same stress regimen, plasma LH and T values were reduced, whereas Prl concentrations were significantly elevated as compared with intact stressed rats. Adrenalectomy alone did not modify basal levels of these hormones. In intact rats, chronic stress did not alter the amount of [125I]iodo-hCG specifically bound to crude testis membrane preparation, or the testicular responsiveness to hCG as measured by T levels 2 h after the injection of hCG (500 IU). In adr-x groups, a significant decrease in binding capacity of [125I]iodo-hCG and no alteration in hCG responsiveness have been observed. From these studies, it appears 1) that plasma T suppression induced by chronic restraint is not initially mediated by a direct action at the testis level as judged by the normal testicular hCG binding capacity and responsiveness to hCG, 2) the sustained endogenous release of glucocorticoid associated with chronic restraint exposure does not play an important role in the decrease of LH and T secretion but could participate in the drop of Prl induced by long-term exposure to stressors, 3) the decrease in LH secretion may be partly responsible for the suppression of T, whereas FSH (on the basis of previous observations) and Prl do not seem to exert a significant role.
Changes in plasma LRH during the normal menstrual cycle in women
Authors: Miyake A. , Kawamura Y. , Aono T. , Kurachi K. 
Published: December 2008

Abstract.
The plasma concentrations of immunoreactive LRH, LH, FSH, oestradiol and progesterone were measured daily by a sensitive double antibody radioimmunoassay during 12 cycles of 8 normal cyclic women. The mean (± se) immunoreactive LRH levels in the follicular and luteal phase except the immunoreactive LRH peaks during normal cycles were 4.18 ± 0.38 pg/ml and 4.50 ± 0.45 pg/ml, respectively. The immunoreactive LRH peaks were observed in 11 of 12 cycles, appearing on day −4 to −1 from the LH surge in 9 cycles and on day +1 and +2 in 2 cycles. The mean value of immunoreactice LRH peaks was 42.0 ± 11.4 pg/ml with range of 12 to 154 pg/ml. The immunoreactive LRH peak lasted for one day in 10 cycles and for 4 days in one cycle. The immunoreactive LRH peaks in different cycles of the same women did not occur on the same day relative to the LH peak. The plasma immunoreactive LRH levels measured every 10 min for 40 min periods every day in normal cyclic women during the ovulatory phase showed slight, but not significant fluctuations. Plasma oestradiol levels began to increase on day −6, reaching a peak on day − 1, and were followed by peaks of LH and FSH. These data indicate that increase in serum oestradiol was followed by release of LRH from the hypothalamus and pre-ovulatory discharge of gonadotrophins from the pituitary.
Panhypopituitarism secondary to head trauma: evidence for a hypothalamic origin of the deficit
Authors: Jambart Selim , Turpin Gerard , de Gennes Jean Luc 
Published: December 2008

Abstract.
A complete endocrinological exploration was performed in a 23 year old male patient who presented clinical signs of an acquired panhypopituitarism which appeared two months after a severe head trauma, in order to determine whether the deficit lay in the hypothalamus or in the pituitary. TSH had normal basal levels, but presented a delayed rise after TRH administration. PRL rose normally after TRH administration, but presented a blunted response to both metoclopramide and insulin tolerance test. Cortisol rose significatively after lysine vasopresssin, but failed to rise during insulin hypoglycaemia. These results are consistent with a hypothalamic defect. Extensive endocrinological data are often lacking in the few similar cases reported in the literature. Prl and TSH were usually found to have normal basal levels while other pituitary hormones were profoundly lowered. This was interpretated as a pituitary defect with some intact areas of the anterior lobe. However, this may also suggest a hypothalamic defect which could have been assessed by more discriminative tests.
Interaction of dopaminergic and antiserotoninergic drugs in the control of prolactin and LH release in normal women
Authors: Pontiroli Antonio E. , Alberetto Miriam , Pellicciotta Gabriele , e Silva Emilio De Castro , De Pasqua Anna , Girardi Anna M. , Pozza Guido 
Published: December 2008

Abstract.
Prolactin (Prl) release, both in the experimental animal and in man, is stimulated by serotonin (5HT) and inhibited by dopamine (DA). Data also suggest that LH release in the animal is stimulated by norepinephrine and inhibited by DA. The role of 5HT in the control of LH release is less clear. It would appear to stimulate episodic LH release and to inhibit the LH surge at the pro-oestrus in animals, but the effect of 5HT on LH release has not yet been evaluated in man. In the present paper we have studied the effect of various DA-ergic drugs (DA, iv 1-dopa, po 1-dopa and bromoergocriptine) and of two anti-5HT drugs, metergoline and methysergide, on Prl and LH release in normal women. DA-ergic drugs lowered plasma Prl and LH levels; anti-5HT drugs, at doses able to lower Prl levels, did not affect basal LH release nor the inhibiting effect of iv 1-dopa on LH release. These data indicate that DA inhibits both LH and Prl release in normal women, and that 5HT stimulates Prl release but is not involved in the regulation of LH secretion. The fact that, at variance to all the DA-ergic drugs used, the two anti-5HT drugs did not vary LH release, suggests that metergoline and methysergide are devoid of DA-ergic activity in man, at least at the doses able to inhibit Prl release.
Dissociation of pituitary glycoprotein response to releasing hormones in chronic renal failure
Authors: LeRoith Derek , Danovitz Gabriel , Trestian Stefan , Spitz Irving M. 
Published: December 2008

Abstract.
The LH, FSH and TSH response to LRH and TRH has been evaluated in patients with chronic renal failure. Basal gonadotrophins were elevated in 3 out of 6 males; one of 4 pre-menopausal females had increased basal LH. Exaggerated LH responses to LRH were noted in 4 out of 6 males and one of 4 females; FSH responses were increased in 3 of these males. One male and one female had attenuated LH and FSH responses to LRH. Both testosterone and oestradiol levels were reduced. In 5 out of 6 subjects tested both pre- and post-dialysis there was a greater LH and FSH response to LRH following dialysis. This suggests the presence of a dialysable toxin which is inhibiting the gonadotrophin response to LRH. Gonadotrophin levels remained elevated during 4 h of dialysis suggesting prolongation of the metabolic clearance rate. Despite low T3 levels, TSH response to TRH (200 μg) was only elicited in 2 of 6 cases. However, all 3 responded to 500 μg and 2 out of 3 to 1000 μg TRH, the third showing an attenuated response. TSH levels also remained persistently elevated in the responders. Dialysis however, failed to improve the relative TSH non-responsiveness to TRH.
In conclusion the data has shown that there is a dissociation in glycoprotein hormone responses to releasing hormones in uraemia. Whereas the gonadotrophs retain their responsiveness to LRH, the thyrotrophs appear to be more effected by the uraemic process and demonstrate an impaired response to TRH.
The failure of L-prolyl-L-leucylglycinamide to inhibit the release of α-melanocyte-stimulating hormone in the rat
Authors: Thody A. J. , de Vries C. H. Lever , Tilders F. J. H. 
Published: December 2008

Abstract.
We have studied the effect of L-prolyl-L-leucylglycinamide (PLG) on the release of melanocytestimulating hormone (MSH) from the rat pituitary gland both in vitro and in vivo.
Superfusion of neurointermediate lobes with medium containing PLG or PLG-acetate (dose range 1–1000 ng/ml) did not affect the spontaneous release of MSH as determined by radioimmunoassay or by bioassay.
Also during static incubations of rat hemipituitaries, PLG (6.6–50 ng/ml) was without effect on α-MSH release.
Administration of PLG (1–250 ng iv) to intact male and female rats and rats bearing lesions in the medio-basal hypothalamus did not induce a fall in serum α-MSH levels.
It is concluded that PLG does not affect the release of α-MSH from the rat intermediate lobe. It is unlikely therefore that PLG mediates the inhibitory influence of the CNS on MSH release.
Thyroid gland function during childhood and adolescence
Authors: Parra A. , Villalpando S. , Junco E. , Urquieta B. , Alatorre S. , García-Bulnes G. 
Published: December 2008

Abstract.
Serum thyrotrophin (TSH), thyroxine (T4), triiodothyronine (T3), thyroxine-binding globulin (TBG) and reverse T3 (rT3) were measured by radioimmunoassay in 175 girls and 187 boys aged 6.0 to 16.9 years, who were clinically healthy, and had negative serum antithyroglobulin and antimicrosomal antibodies. All the children had normal weight and height and were grouped at 12 months' intervals. In girls, TSH levels ranged between 5.3 ± 0.4 and 6.9 ± 0.5 μU/ml without significant changes with age; serum T4 decreased up to 13.9 years and rose afterwards; serum TBG was constant up to 13.9 years, decreased subsequently and rose after 15.9 years; serum T3 levels were lower after 13.0 years than previously; serum rT3 decreased between 11.0 and 11.9 years and rose thereafter; the calculated serum free T4 (FT4) and free T3 (FT3) concentrations had a significant rise from 14.0 to 15.9 years followed by a sharp decline; T3:T4, rT3:T3 and rT3:T4 ratios were constant up to 11.9 years, then a rise was seen in T3:T4 and a fall in the later ratios, followed by a drop in T3:T4 ratio and a sustained rise in rT3:T3 and rT3:T4 ratios. In boys, TSH levels were constant between 5.2 ± 0.4 and 6.6 ± 0.4 μU/ml; serum T4 decreased with increasing age; serum TBG was constant up to 13.9 years, and had a sustained fall thereafter; serum T3 was constant over the age range studied; serum rT3 levels decreased up to 13.9 years and rose thereafter; FT4 had no changes with increasing age while FT3, although constant up to 13.9 years, had a sustained rise afterwards; T3:T4 ratio did not change with age, while rT3:T3 and rT3:T4 ratios, although constant up to 13.9 years, showed a tendency toward a sustained rise thereafter. These sex-different variations in serum thyroid hormone concentrations might be related to the fact that girls mature at an earlier chronological age than boys and may represent a partial response of the body to the qualitatively and quantitatively different energy needs in girls as compared with boys, consecutive to the differences in body composition first appearing at puberty.
Interrelationships between energy metabolism and thyroid hormone metabolism during starvation in the rat
Authors: Burger A. G. , Berger M. , Wimpfheimer K. , Danforth E. 
Published: December 2008

Abstract.
Thyroid hormone metabolism and plasma concentrations of TSH were studied after short-term hypocaloric refeeding of rats starved for 2–6 days. Carbohydrate and protein (10 kcal) refeeding after 4 days of starvation resulted in a rapid increase in serum T3 (P<0.01) and, less consistently of T4. Plasma TSH did not change. These findings were not due to changes in the metabolic clearance rates or in thyroid hormone binding proteins, as the disappearance of injected labelled T3 and T4, and the free fractions of T3 and T4, were unchanged. Increased thyroidal secretion, and for T3, increased peripheral conversion from T4 were therefore responsible for these changes. Fat refeeding had no immediate effect on plasma T4, T3 or TSH. After 6 days of starvation, refeeding of any nutrient was ineffective in altering the plasma concentrations of T3 and T4.
The intraperitoneal administration of nicotinamide (100 mg/100 g body weight) to starving animals caused an increase in blood glucose and a decrease in blood betahydroxybutyrate similar to that which followed carbohydrate refeeding; T3, however, did not increase. In spite of producing a profile of substrates in the serum similar to that found following carbohydrate refeeding, nicotinamide administration had no effect on the blood lactate/ pyruvate ratio which was increased following carbohydrate refeeding. Therefore, the cytoplasmic redox state, as reflected by the lactate/pyruvate ratio, may be closely related to the control of peripheral thyroid hormone metabolism.
Effect of ACTH on the proliferative and secretory activities of the adrenal glomerulosa
Authors: Payet N. , Lehoux J.-G. , Isler H. 
Published: December 2008

Abstract.
The mitotic, trophic and secretory responses of the adrenal cortex to various preparations and doses of ACTH were investigated in the rat. 1-24-ACTH depot (Synacthen) elicited the highest mitotic and trophic stimulation. The mitotic stimulation occurred exclusively in the glomerulosa, the trophic stimulation occurred mainly in the fasciculata-reticularis and the functional stimulation was found in both, as indicated by the plasma aldosterone and corticosterone levels. The functional changes occurred first, the trophic changes later. Large doses of ACTH inhibited cell proliferation in the fasciculata. The trophic action consisted in an enlargement of the adrenal, to a great extent in the fasciculata-reticularis, and to a lesser extent in the glomerulosa. This enlargement was due partly to parenchymal cell hypertrophy, but also and mostly to stromal hypertrophy, especially hyperaemia. The largest dose of ACTH caused a considerable widening of the sinusoids of the fasciculata-reticularis and medulla, and possibly caused a loss of parenchymal cells in the reticularis. These effects are reminiscent of the well documented haemorrhagic conditions of the adrenals in humans.
Further studies on the inactivation of thyrotrophin releasing hormone (TRH) by enzymes in the rat hypothalamus
Authors: Griffiths E. C. , Kelly J. A. , White N. , Jeffcoate S. L. 
Published: December 2008

Abstract.
Thyrotrophin-releasing hormone (TRH) is known to be inactivated by enzymes present in the rat hypothalamus. To make a further study of the enzymes' action on the tripeptide, synthetic TRH was incubated with two hypothalamic subcellular fractions. By using a direct radioimmunoassay for TRH, the tripeptide was shown to be rapidly degraded by both supernatant and particulate fractions, with higher enzyme activity in the particulate fraction. Of several biologically-active peptides tested, only luteinizing hormone-releasing hormone was found to inhibit TRH inactivation; bacitracin, a polypeptide antibiotic, was also effective in inhibiting inactivation. Enzyme activity was highest in the middle hypothalamic area and lowest in the posterior hypothalamic area. Thin layer chromatography of the products of enzyme cleavage revealed the formation of only deamidated TRH in the supernatant fraction and the constituent amino acids (pyroGlu, His, ProNH2) and histidylproline-diketopiperazine by the particulate fraction, suggesting the presence of an amidase in the supernatant and two peptidases in the particulate fractions. These properties of the enzymes inactivating TRH may indicate that the enzymes could be of importance in regulating the endocrine and other functions attributed to this hypothalamic regulatory hormone.
Red-cell 2,3-diphosphoglycerate in patients with hyperthyroidism
Authors: Alvarez-Sala J. L. , Urbán M. A. , Sicilia J. J. , Fdez A. J. Diaz , Mendieta F. Fdez , Espinós D. 
Published: December 2008

Abstract.
In 21 hyperthyroid female patients studied on 29 occasions, high levels of red-cell 2,3-diphosphoglycerate (2,3-DPG) have been found (5.75 ± 0.7 mm) which, compared to a euthyroid control group (4.88 ± 0.4 mm), could not be accounted for by differences in haematocrit, haemoglobin or phosphataemia. A significant correlation was found (P < 0.05) between serum thyroid hormones and the 2,3-DPG concentration in the hyperthyroid patients. Eight of these patients were reexamined after treatment and normalization of thyroid function, showed a regression to normal 2,3-DPG values (4.81 ± 0.6 mm) which could not be attributed to variations in haematocrit, haemoglobin or phosphataemia either. We therefore deduce that the shift to the right in the haemoglobin oxygen dissociation curve observed in patients of this type may be due to an increase in the red-cell 2,3-DPG content.
Thyroid hormone levels related to energy and nitrogen balance during weight loss and regain in adult sheep
Authors: Blum J. W. , Gingins M. , Vitins P. , Bickel H. 
Published: December 2008

Abstract.
Caloric deprivation (feeding 50 and 25% of the original maintenance requirement for 126 days), followed by overnutrition (feeding 133 and 200% of the original maintenance requirement) for 37 days, were induced in 7 adult sheep. Before and after the periods of undernutrition and after overnutrition the animals were fasted (total energy withdrawal) for 5 days. Energy- and nitrogen-balances were determined and related to concentrations of thyroxine (total: T4; free: FT4), 3,5,3′-triiodothyronine (total: T3; free: FT3) and 3,3′,5′-triiodothyronine (reverse T3,rT3).
Caloric deprivation led to decreased T3 and FT3 levels, overnutrition to increased T3 and FT3 concentrations. T3 was significantly correlated with energy- and nitrogen-balances (r = 0.73 and 0.71, respectively; P< 0.001). T4 and FT4 behave similar to T3, but correlations between T4 levels and energy- and nitrogen-balances were low. In contrast to T3, rT3 levels increased during energy withdrawal and decreased during overnutrition. After an overnutrition for months, an additional fasting for 5 days did not increase rT3 levels, however. rT3 was significantly correlated with energy- and nitrogen-balances (r = −0.50 and −0.50, respectively; P < 0.01).