Testosterone Inhibition of Growth Hormone Release Stimulated by a Growth Hormone Secretagogue

2006 ◽  
Vol 84 (2) ◽  
pp. 115-122 ◽  
Author(s):  
Antonello E. Rigamonti ◽  
Silvano G. Cella ◽  
Claudio Giordani ◽  
Sara M. Bonomo ◽  
Marialuisa Giunta ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Growth Hormone Secretagogue ◽  
Inhibition Of Growth

Cycloheximide blocks insulin-like growth factor I but not somatostatin inhibition of growth hormone secretion

1987 ◽  
Vol 65 (4) ◽  
pp. 515-519 ◽  
Author(s):  
M. S. Sheppard ◽  
R. M. Bala
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Protein Synthesis Inhibitor ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Synthesis Inhibitor ◽  
Inhibition Of Growth ◽  
Igf I

Growth hormone secretion is controlled by the two hypothalamic hormones, growth hormone releasing factor (GRF) and somatostatin. In addition, the insulin-like growth factors (IGF or somatomedins) which are themselves growth hormone dependent, inhibit growth hormone release in vitro, therefore acting to close the negative feedback loop. The studies reported here examine some of the differences between inhibition of growth hormone secretion by somatostatin and IGF-I in vitro. The major finding is that cycloheximide, a protein synthesis inhibitor, blocks inhibition of GRF-stimulated growth hormone release caused by IGF-I, without changing the inhibition caused by somatostatin. The experiments were done by exposing mixed rat adenohypophysial cells to secretagogues with or without cycloheximide for 24 h in a short term culture. Somatostatin (0.6 nM) totally blocked rat GRF (1 nM) stimulated growth hormone release to values 48% of control (nonstimulated values), while IGF-1 (27 nM) only reduced the GRF-stimulated growth hormone release by 27 ± 3% (N = 5). Cycloheximide (15 μg/mL) totally blocked the effect of IGF-I but not somatostatin. A low concentration (0.12 nM) of somatostatin, which only partly inhibited growth hormone release, was also unaffected by cycloheximide. In purified rat somatotrophs, somatostatin (0.1 nM) inhibited GRF-stimulated cAMP levels slightly and reduced growth hormone release while IGF-I (40 nM) had no effect. We suggest that IGF-I inhibits only the secretion of newly synthesized growth hormone, while somatostatin inhibits both stored and newly synthesized growth hormone pools.

scholarly journals Somatostatin receptor subtype 1 modulates basal inhibition of growth hormone release in somatotrophs

FEBS Letters ◽  
1999 ◽  
Vol 462 (3) ◽  
pp. 464-466 ◽  
Author(s):  
Hans-Jürgen Kreienkamp ◽  
Ercan Akgün ◽  
Hans Baumeister ◽  
Wolfgang Meyerhof ◽  
Dietmar Richter
Keyword(s):  
Growth Hormone ◽  
Somatostatin Receptor ◽  
Receptor Subtype ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Inhibition Of Growth

scholarly journals 133. Adenovirus-Light Chain Inhibition of Growth Hormone Release from Pituitary Adenoma Cells

2006 ◽  
Vol 13 ◽  
pp. S54 ◽  
Author(s):  
Thais Federici ◽  
Qingshan Teng ◽  
Mary Garrity-Moses ◽  
Christina Krudy ◽  
Jun Yang ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Adenoma ◽  
Light Chain ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Inhibition Of Growth

Inhibition of growth hormone release after the combined administration of CHRH and GHRP-6 in patients with Cushing's syndrome

1994 ◽  
Vol 41 (5) ◽  
pp. 649-654 ◽  
Author(s):  
Alfonso Leal-Cerro ◽  
Alfonso Pumar ◽  
Emlllo Garcia-Garcia ◽  
Carlos Dieguez ◽  
Felipe F. Casanueva
Keyword(s):  
Growth Hormone ◽  
Cushing’S Syndrome ◽  
Cushing's Syndrome ◽  
Hormone Release ◽  
Growth Hormone Release ◽  
Inhibition Of Growth ◽  
Combined Administration
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