Effects of muscarinic and adrenergic blockade on growth hormone secretion induced by growth hormone-releasing peptide-2 (GHRP-2) in ovariectomized ewes.
This study was performed to investigate whether the blockade of cholinergic muscarinic and adrenergic pathways was involved in the GH-releasing effect of GH-releasing peptide-2 (GHRP-2) in ovariectomized ewes. Cholinergic muscarinic antagonist, atropine (0.2 mg/kg, i.v., 15 min before GHRP-2 administration) blunted the GH secretion caused by GHRP-2 (12.5 microg/kgBW). alpha-Adrenergic antagonist phentolamine (15 microg/kgBW x min, infusion from -15 to 30 min) did not affect the GH response to GHRP-2, and beta-adrenergic antagonist propranolol (0.25 mg/kgBW, i.v., 15 min before GHRP-2 administration) did not suppress the GHRP-2-induced GH release. These results showed that cholinergic muscarinic antagonist agent, atropine, exerts an inhibitory effect on GHRP-2-induced GH secretion in ovariectomized ewes.
Roh
S G
SG
Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Hirota
M
M
He
M L
ML
Matsunaga
N
N
Hidaka
S
S
Hidari
H
H
D018674:Adrenergic Antagonists / Q000627:therapeutic use*; D000818:Animals; D005260:Female; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology*; D018727:Muscarinic Antagonists / Q000627:therapeutic use*; D009842:Oligopeptides / Q000494:pharmacology*; D010052:Ovariectomy; D010053:Ovary / Q000502:physiology; D012636:Secretory Rate / Q000187:drug effects; D012756:Sheep
D018674:Adrenergic Antagonists; D006728:Hormones; D018727:Muscarinic Antagonists; D009842:Oligopeptides; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; C091874:growth hormone-releasing peptide-2