Stimulation of in-vivo growth hormone secretion in young chickens by rat hypothalamic growth hormone-releasing factor and synthetic analogues.
Rat hypothalamic GH-releasing factor (rhGRF), at doses between 0.1 and 10 micrograms/kg, increased plasma GH concentrations in immature domestic fowl 5-10 min after i.v. injection. Sodium pentobarbitone anaesthesia blunted the GH responses to rhGRF, although in both conscious and anaesthetized chicks the maximal responses were induced by a dose of 1 microgram rhGRF/kg. The stimulatory effect of rhGRF on in-vivo GH secretion was less than that provoked by corresponding doses of human pancreatic GRF, but greater than that elicited by two rhGRF analogues, (Nle27)-rhGRF(1-32) and (Nle27)-rhGRF(1-29). These results demonstrate that the chicken pituitary is responsive to mammalian GRF and provide evidence of structure-activity relationships of GRF in the domestic fowl.
D000818:Animals; D002645:Chickens; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology*; D010424:Pentobarbital; D010446:Peptide Fragments / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013268:Stimulation, Chemical; D013329:Structure-Activity Relationship
D006728:Hormones; D010446:Peptide Fragments; C036893:somatotropin releasing factor 40; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D010424:Pentobarbital