Testicular regulation of sexual dimorphisms in the ultradian profiles of circulating growth hormone in the chicken

1994 ◽  
Vol 131 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Nisar A Pampori ◽  
Bernard H Shapiro
Keyword(s):  
Growth Hormone ◽  
Right Atrial ◽  
University Of Pennsylvania ◽  
Sexually Dimorphic ◽  
White Leghorn ◽  
Plasma Growth Hormone ◽  
Blood Samples ◽  
Sexual Dimorphisms ◽  
The Common ◽  
Plasma Gh

Pampori NA, Shapiro BH. Testicular regulation of sexual dimorphisms in the ultradian profiles of circulating growth hormone in the chicken. Eur J Endocrinol 1994;131:313–318. ISSN 0804–4643 Ultradian patterns in plasma growth hormone (GH) concentrations were determined in adult white Leghorn roosters, hens and capons. Serial blood samples were collected every 15 min over 8 h through surgically placed chronic indwelling right atrial catheters and assayed for GH content by a homologous radioimmunoassay. In both sexes, GH levels fluctuated episodically, with peak and interpeak periods each lasting about 45 min in both roosters and hens. However, GH concentrations in the peaks and nadirs were 2.5–3.5 times greater in the plasma GH profiles of roosters as compared to hens, which resulted in roosters having higher mean GH concentrations. Caponizing completely feminized the episodic GH secretory profile. In contrast to chickens, the common sexually dimorphic feature in secretory GH profiles of mammals is the enhanced peak frequencing found in females. Bernard H Shapiro, Laboratories of Biochemistry, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104-6048, USA

PITUITARY FUNCTION AFTER YTTRIUM IMPLANTS AS MEASURED BY PLASMA GROWTH HORMONE LEVELS

1971 ◽  
Vol 50 (1) ◽  
pp. 41-50 ◽  
Author(s):  
HELEN J. STEWART ◽  
E. A. BENSON ◽  
M. MAUREEN ROBERTS ◽  
A. P. M. FORREST ◽  
F. C. GREENWOOD
Keyword(s):  
Breast Cancer ◽  
Growth Hormone ◽  
Advanced Breast Cancer ◽  
Adrenal Function ◽  
Advanced Breast ◽  
Pituitary Function ◽  
Post Mortem ◽  
Plasma Growth Hormone ◽  
Fasting Level ◽  
Plasma Gh

SUMMARY Plasma growth hormone (GH) levels during insulin hypoglycaemia were measured in 30 women with implants of 90Y in the pituitary for advanced breast cancer. There was evidence of continued pituitary activity in six patients (20%), the rise in plasma GH level being greater than 4 ng/ml during hypoglycaemia. Thirteen patients (43%) were regarded as having complete ablations because they had no GH response and a fasting level of less than 4 ng/ml. In the remaining 11 patients (37%) there was no rise in the GH level during hypoglycaemia, but there were significant fasting levels. From the post-mortem evidence it was concluded that these patients also had adequate ablations. This test is shown to be of more value in estimating residual pituitary function than routine tests of thyroid or adrenal function.

Imitation of normal plasma growth hormone profile by subcutaneous administration of human growth hormone to growth hormone deficient children

1983 ◽  
Vol 102 (1) ◽  
pp. 6-10 ◽  
Author(s):  
J. Sandahl Christiansen ◽  
H. Ørskov ◽  
C. Binder ◽  
K. W. Kastrup
Keyword(s):  
Growth Hormone ◽  
Time Course ◽  
Subcutaneous Administration ◽  
Molecular Size ◽  
Hormone Deficiency ◽  
Gel Chromatography ◽  
Plasma Growth Hormone ◽  
Normal Children ◽  
Blood Samples ◽  
Long Term Treatment

Abstract. The time course of plasma growth hormone (hGH) levels following sc and im injection of hGH was studied in 12 children with growth hormone deficiency who had received long-term treatment with im injections of highly purified hGH. Also the spontaneous diurnal GH levels in 8 normal children of comparable age were recorded. Blood samples were obtained during 24 h after im and sc injections of 4 IU/m2 hGH and analysed for immunoreactive hGH. While a median peak value of 160 ng/ml (range 135 to 475 ng/ml) was obtained 2 h after im injection, sc injection resulted in a more sustained elevation reaching 41 ng/ml (range 32 to 51 ng/ml) at 6 h subsiding slowly with a median concentration of 15 ng/ml (range 5–24 ng/ml) persisting after 14 h. Gel chromatography demonstrated that the hGH immunoreactivity of blood samples obtained as late as 14 h after sc injection had unaltered molecular size. Seven of the patients were further studied after sc injection of 2 IU/m2 at 20.00 h instead of in the morning. A plasma profile was attained during the night which roughly approximated the average nocturnal plasma pattern of the normal children.

RELATIONSHIP BETWEEN LAMB BIRTH WEIGHTS AND FETAL PLASMA GROWTH HORMONE AND INSULIN CONCENTRATIONS

1986 ◽  
Vol 66 (4) ◽  
pp. 995-1001
Author(s):  
G. J. MEARS
Keyword(s):  
Growth Hormone ◽  
Fetal Growth ◽  
Plasma Insulin ◽  
Plasma Concentrations ◽  
Maternal Plasma ◽  
Metabolic Clearance ◽  
Plasma Growth Hormone ◽  
Fetal Plasma ◽  
Plasma Gh ◽  
Ovine Fetal

Plasma concentrations of growth hormone (GH) and insulin were monitored in 11 chronically cannulated ovine fetuses and their mothers during the last month of gestation to obtain information on the role that these hormones have in determining fetal growth rate. Maternal plasma GH and insulin concentrations were independent of stage of gestation and lamb birth weights. Fetal plasma insulin concentrations were episodic in nature, independent of stage of gestation, and tended to be higher in fetuses that were heavier at birth. Fetal plasma GH concentrations were only slightly episodic in nature, were tenfold higher than maternal levels at 116–124 d gestation and increased by approximately another 25% prior to parturition. Fetal plasma GH concentrations were negtively correlated with lamb birth weights. In twin preparations, fetal plasma GH concentrations were significantly lower in the twin that was heaviest at birth. The lower GH concentrations found in faster growing fetuses are suggestive of a more rapid metabolic clearance of GH by the tissues of these animals. The results indicate that circulating fetal GH and, possibly, insulin are involved in determining the rate of ovine-fetal growth. Key words: Ovine birth weights, fetal GH, fetal insulin, fetal growth

Generation of growth hormone pulsatility in women: evidence against somatostatin withdrawal as pulse initiator

2001 ◽  
Vol 280 (3) ◽  
pp. E489-E495 ◽  
Author(s):  
Eleni V. Dimaraki ◽  
Craig A. Jaffe ◽  
Roberta Demott-Friberg ◽  
Mary Russell-Aulet ◽  
Cyril Y. Bowers ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Growth Hormone ◽  
Postmenopausal Women ◽  
Normal Saline ◽  
Driving Force ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Blood Samples ◽  
Stable Plasma ◽  
Plasma Gh

To test whether endogenous hypothalamic somatostatin (SRIH) fluctuations are playing a role in the generation of growth hormone (GH) pulses, continuous subcutaneous octreotide infusion (16 μg/h) was used to create constant supraphysiological somatostatinergic tone. Six healthy postmenopausal women (age 67 ± 3 yr, body mass index 24.7 ± 1.2 kg/m2) were studied during normal saline and octreotide infusion providing stable plasma octreotide levels of 2,567 ± 37 pg/ml. Blood samples were obtained every 10 min for 24 h, and plasma GH was measured with a sensitive chemiluminometric assay. Octreotide infusion suppressed 24-h mean GH by 84 ± 3% ( P = 0.00026), GH pulse amplitude by 90 ± 3% ( P = 0.00031), and trough GH by 54 ± 5% ( P = 0.0012), whereas GH pulse frequency remained unchanged. The response of GH to GH-releasing hormone (GHRH) was not suppressed, and the GH response to GH-releasing peptide-6 (GHRP-6) was unaffected. We conclude that, in women, periodic declines in hypothalamic SRIH secretion are not the driving force of endogenous GH pulses, which are most likely due to episodic release of GHRH and/or the endogenous GHRP-like ligand.

Manipulation of protein and fat accretion in growing cattle

1991 ◽  
Vol 1991 ◽  
pp. 18-18
Author(s):  
J.M. Dawson ◽  
D.E. Beever ◽  
P.J. Buttery ◽  
M. Gill
Keyword(s):  
Growth Hormone ◽  
Muscle Protein ◽  
Adrenergic Agonists ◽  
Plasma Growth Hormone ◽  
Direct Stimulation ◽  
Hormone Administration ◽  
Young Cattle ◽  
Plasma Gh

ß-adrenergic agonists are powerful repartitioning agents, increasing muscle protein accretion and reducing fat deposition in a variety of species. Their exact mode of action is not fully understood but some of their effects are similar to those elicited by exogenous growth hormone administration. Whilst there are few reports of plasma growth hormone (GH) concentrations being elevated in animals treated with ß-agonists, several in vitro studies have clearly demonstrated a direct stimulation of GH release from perifused or cultured pituitary or adenohypophyseal cells on administration of these agents. More recently, a brief, rapid rise in plasma GH has been demonstrated in rats infused intra-atrially with isoproterenol and this was sustained when the animals were pre-treated with somatotropin release inhibitory factor (somatostatin; SRIF) antiserum. This raises the possibility that ß-adrenergic agonists do stimulate GH release in vivo but that this response is rapidly counteracted by SRIF release.The aim of this work was to attempt to enhance the repartitioning effect of ß-adrenergic agonists by immunizing young cattle against SRIF whilst administering cimaterol.

scholarly journals In vitro lipid metabolism, growth and metabolic hormone concentrations in hyperthyroid chickens

1992 ◽  
Vol 68 (3) ◽  
pp. 667-676 ◽  
Author(s):  
R. W. Rosebrough ◽  
J. P. McMurtry ◽  
R. Vasilatos-Younken
Keyword(s):  
Growth Hormone ◽  
Broiler Chickens ◽  
Lipid Synthesis ◽  
High Rate ◽  
Feed Consumption ◽  
Plasma Growth Hormone ◽  
Indian River ◽  
Plasma Gh ◽  
Metabolic Hormone

Indian River male broiler chickens growing from 7 to 28 d of age were fed on diets containing energy: protein values varying from 43 to 106 MJ/kg protein and containing 0 or 1 mg triiodothyronine (T3)/kg diet to study effects on growth, metabolic hormone concentrations and in vitro lipogenesis. In vitro lipid synthesis was determined in liver explants in the presence and absence of ouabain (Na+, K+-transporting ATPase (EC 3.6.1.37) inhibitor) to estimate the role of enzyme activity in explants synthesizing lipid. Growth and feed consumption increased (P < 0.01) when the energy: protein value decreased from 106 to 71 MJ/kg protein; however, both variables decreased as the value was further decreased from 53 to 43 MJ/kg protein. Triiodothyronine depressed (P < 0.01) growth, but not food intake. Large energy:protein diets (> 53 MJ/kg protein) and dietary T3 lowered (P < 0.01) plasma growth hormone. Large energy:protein diets (> 53 MJ/kg protein) increased (P < 0.01) lipogenesis, plasma growth hormone (GH) and decreased plasma insulin-like growth factor 1 (IGF-1). Also, T3 decreased plasma GH, IGF-1 in vitro lipogenesis. Ouabain inhibited a greater proportion of in vitro lipogenesis in those explants synthesizing fat at a high rate. Both dietary T3 and in vitro ouabain decrease lipogenesis, but, when combined, the effects are not cumulative

Relationship between plasma growth hormone concentration and cellular sodium transport in acromegaly

1992 ◽  
Vol 127 (1) ◽  
pp. 38-43 ◽  
Author(s):  
Hans Herlitz ◽  
Olof Jonsson ◽  
Bengt-Åke Bengtsson
Keyword(s):  
Growth Hormone ◽  
Sodium Transport ◽  
Negative Relationship ◽  
Sodium Content ◽  
Plasma Growth Hormone ◽  
Sodium Influx ◽  
Active Acromegaly ◽  
One Year ◽  
Plasma Gh

We investigated the relationship between mean plasma growth hormone (GH) concentration and cellular sodium transport in untreated and treated acromegaly. Seventeen patients (age 55±3 years) with active acromegaly were studied with respect to plasma GH (mean of 24 h GH profile) and erythrocyte electrolyte content as well as transmembrane sodium transport. The patients were reinvestigated two weeks after successful surgery (N=14) and again after one year (N=13). Erythrocyte electrolytes were analyzed by flame photometry and sodium influx and efflux rate constant determined by in vitro incubation using a modified Keyne's formula. In patients with active acromegaly there was a significant positive correlation between IGF-1 and cellular sodium transport, while GH tended to show a negative relationship to the same parameter. After successful treatment, both IGF-1 and GH disclosed a positive relationship to cellular sodium transport. After one year, a significant increase in erythrocyte sodium content was seen in the patients compared to the preoperative situation. In conclusion, if this is a generalized phenomenon the results are compatible with a sodium-retaining effect of GH via stimulation of transmembrane sodium transport. In active acromegaly this may be counteracted by a sodium transport inhibitor giving the reverse relationship between GH and cellular sodium transport.

Effects of Subcutaneous Sumatriptan on Plasma Growth Hormone Concentrations in Migraine Patients

Cephalalgia ◽  
2000 ◽  
Vol 20 (4) ◽  
pp. 223-227 ◽  
Author(s):  
L Pinessi ◽  
I Rainero ◽  
L Savi ◽  
W Valfrè ◽  
P Limone ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Adverse Effects ◽  
Healthy Controls ◽  
Plasma Growth Hormone ◽  
Blood Samples ◽  
Subcutaneous Sumatriptan

The purpose of this study was to assess the sensitivity of 5-HT1D receptors in migraine using sumatriptan as a pharmacological probe. The drug stimulates the release of growth hormone (GH) and this effect may be used to explore the function of cerebral serotonergic systems in vivo. We administered sumatriptan and placebo to 15 migraineurs and to 10 controls. Blood samples were collected -15, 0, 15, 30, 45, 60 and 90 min after injection. Placebo had no effect on hormone concentrations. Sumatriptan induced a significant ( P < 0.01) increase in GH concentrations both in migraine patients and healthy controls. The GH increase was not significantly different in the two groups. Our results suggest that cerebral serotonergic functions mediated by 5-HT1D receptors are not altered in migraine. Sumatriptan overuse could lead to adverse effects mediated by its neuroendocrine activity.

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