Influence of catecholamines, prostaglandins and thyroid hormones on growth hormone secretion by chicken pituitary cells in vitro

1990 ◽  
Vol 7 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Dan J. Donoghue ◽  
Frank M. Perez ◽  
Bruce S.A. Diamante ◽  
Sasha Malamed ◽  
Colin G. Scanes
Keyword(s):  
Growth Hormone ◽  
Thyroid Hormones ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells

Glucocorticoid modulation of growth hormone secretion in vitro. Evidence for a biphasic effect on GH-releasing hormone mediated release

1987 ◽  
Vol 114 (4) ◽  
pp. 465-469 ◽  
Author(s):  
Gian Paolo Ceda ◽  
Robert G. Davis ◽  
Andrew R. Hoffman
Keyword(s):  
Growth Hormone ◽  
Prolonged Exposure ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Inhibitory Effect ◽  
Pituitary Cells ◽  
Gh Secretion ◽  
Glucocorticoid Action

Abstract. Glucocorticoids have been shown to have both stimulatory and suppressive effects on GH secretion in vitro and in vivo. In order to study the kinetics of glucocorticoid action on the somatotrope, cultured rat pituitary cells were exposed to dexamethasone for varying periods of time. During short-term incubations (≤ 4 h), dexamethasone inhibited GHRH and forskolin-elicited GH secretion, but during longer incubation periods, the glucocorticoid enhanced both basal and GHRH-stimulated GH release. The inhibitory effect of brief dexamethasone exposure was also seen in cells which previously had been exposed to dexamethasone. In addition, growth hormone secretion from cultured rat and human somatotropinoma cells was inhibited by a brief exposure to dexamethasone. Thus, the nature of glucocorticoid action on the isolated cultured somatotrope is biphasic, with brief exposure inhibiting, and more prolonged exposure stimulating GH secretion.

Effects in vitro of New Growth Hormone Releasing Peptide (GHRP-1) on Growth Hormone Secretion from Ovine Pituitary Cells in Primary Culture

1994 ◽  
Vol 6 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Danxing Wu ◽  
Chen Chen ◽  
Jin Zhang ◽  
Kazuo Katoh ◽  
Lain Clarke
Keyword(s):  
Growth Hormone ◽  
Primary Culture ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells

On the role of the peptide galanin in regulation of growth hormone secretion

1991 ◽  
Vol 125 (5) ◽  
pp. 518-525 ◽  
Author(s):  
Anna-Lena Hulting ◽  
Björn Meister ◽  
Lena Carlsson ◽  
Agneta Hilding ◽  
Olle Isaksson
Keyword(s):  
Growth Hormone ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells ◽  
Anterior Pituitary Cells ◽  
Human Anterior Pituitary ◽  
Plasma Gh

Abstract. The effects of the peptide galanin on growth hormone secretion were studied in vitro using cultured rat and human anterior pituitary cells, and in vivo by iv administration of galanin in both rats and humans. Galanin in concentrations from 10 nmol/l to 1 μmol/l did not alter basal GH release, but slightly inhibited GHRH-stimulated GH release from cultured rat anterior pituitary cells. Galanin (1 μmol/l) did not significantly change basal or GHRH-stimulated GH secretion from cultured human anterior pituitary cells. In contrast, iv injection of 1 μg (300 pmol) galanin to rats induced an increase in plasma GH that was reproducible at repetitive injections. The galanin-induced GH release in rats was of a lower magnitude than the increase in plasma GH after iv injections of GHRH, and was seen with a 5-15 min delay in comparison to iv administered GHRH. In man, iv infusions of galanin (40 pmol ·kg−1 · min−1 · (40 min)) also caused a significant increase in plasma GH, but it occurred 25-30 min after the beginning of the infusion. These results suggest an indirect action of galanin on GH release in both rats and humans, i.e. galanin does not directly affect the somatotropes. In agreement with a central action, no binding sites for galanin could be demonstrated in the rat anterior pituitary by autoradiography. Since galanin did not affect somatostatin release from fragments of rat mediobasal hypothalamus, the stimulatory effects of galanin on GH release are most likely mediated via a stimulatory effect on GHRH neurons.

EFFECT OF CHICKEN HYPOTHALAMUS ON PROLACTIN AND GROWTH HORMONE SECRETION IN MALE CHICKENS

1979 ◽  
Vol 82 (2) ◽  
pp. 193-197 ◽  
Author(s):  
S. HARVEY ◽  
C. G. SCANES ◽  
A. CHADWICK ◽  
G. BORDER ◽  
N. J. BOLTON
Keyword(s):  
Growth Hormone ◽  
Medulla Oblongata ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells ◽  
Plasma Prolactin ◽  
Gh Secretion ◽  
Brain Tissues

SUMMARY The effects of a chicken hypothalamic extract (HE) on the secretion of prolactin and growth hormone (GH) in vivo have been investigated by radioimmunoassay in the domestic fowl. Different i.v. doses of HE (0·25–25 HE equivalents/kg body weight) had no effect on GH secretion in conscious or anaesthetized cockerels. In both groups of birds the concentration of plasma prolactin was significantly increased within 10 min of administration of the extract. Extracts of other brain tissues (cerebral cortex, cerebellum and medulla oblongata) had no stimulatory effect on prolactin or GH secretion. Release of both prolactin and GH by dispersed pituitary cells and by hemipituitary glands in vitro was enhanced following incubation with HE (5 hypothalami equivalents/ml) or with single whole hypothalami respectively. Other brain tissues (cerebellum, optic lobes and medulla oblongata) had no effect on the concentration of prolactin or GH released by incubated hemipituitary glands.

scholarly journals Direct effects of tamoxifen on growth hormone secretion by pituitary cells in vitro

1992 ◽  
Vol 28 (4-5) ◽  
pp. 788-793 ◽  
Author(s):  
Suzanne A Malaab ◽  
Michael N Pollak ◽  
Cynthia G Goodyer
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Cells ◽  
Direct Effects

Exogenous Growth Hormone Inhibits Bovine but Not Murine Pituitary Growth Hormone Secretion in vitro: Evidence for a Direct Feedback of Growth Hormone on the Pituitary

1991 ◽  
Vol 53 (6) ◽  
pp. 597-600 ◽  
Author(s):  
Stephen M. Rosenthal ◽  
Bernhard L. Silverman ◽  
William B. Wehrenberg
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Pituitary Growth Hormone ◽  
Exogenous Growth ◽  
Direct Feedback

The In Vitro Regulation of Growth Hormone Secretion by Orexins

Endocrine ◽  
2003 ◽  
Vol 22 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Chen Chen ◽  
Ruwei Xu
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Regulation Of Growth
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