The interaction of human pancreatic growth hormone releasing factor 1-44 with somatostatin in vivo in normal man.
The interaction between the stimulatory effects of hpGRF 1-44 and the inhibitory effects of somatostatin on GH release have been investigated in six normal male subjects receiving continuous 4 h infusions of these peptides alone and in combination. hpGRF 1-44 0.3 microgram/kg/h alone produced a peak GH response of 27.0 +/- 7.6 mU/l (mean +/- SEM). Somatostatin 1.0 microgram/kg/h markedly inhibited the GH response to hpGRF 1-44 with mean levels less than 4.0 mU/l during the infusion, though a rebound rise in GH levels to 26.1 +/- 9.0 mU/l was observed at the end of the infusion period. Somatostatin 0.2 microgram/kg/h inhibited the GH response to hpGRF 1-44 to a lesser degree (peak GH during the infusion 11.7 +/- 2.5 mU/l) and the rebound rise in GH levels (maximum 13.2 +/- 4.3 mU/l) was less than that observed with high dose somatostatin. During somatostatin 1.0 microgram/kg/h alone GH levels were suppressed less than 1.0 mU/l followed by a rebound at the end of the infusion in only two subjects. These data demonstrate a dose-dependent inhibition of hpGRF 1-44 by somatostatin in vivo in man.
Davies
R R
RR
Turner
S J
SJ
Orskov
H
H
Johnston
D G
DG
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D005934:Glucagon / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D013007:Growth Hormone-Releasing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D013004:Somatostatin / Q000494:pharmacology*
D001786:Blood Glucose; D007328:Insulin; D010446:Peptide Fragments; D013004:Somatostatin; D013006:Growth Hormone; D005934:Glucagon; D013007:Growth Hormone-Releasing Hormone