Evidence that opiatergic and alpha-adrenergic mechanisms stimulate rat growth hormone release via growth hormone-releasing factor (GRF).
An antiserum raised against human pancreatic growth hormone-releasing factor-(1-40) (hpGRF-40) was found to recognize the rat hypothalamic growth hormone-releasing factor (rhGRF): This antiserum, when given iv to adult male rats, completely abolished GH release induced by a synthetic rhGRF (0.2, 1 microgram/kg BW), and inhibited the physiological GH secretion over 2 days. After passive immunization with anti-hpGRF-40 serum, iv injection of either FK 33-824 (100 micrograms/kg BW), an enkephalin analogue, or clonidine (125 micrograms/kg BW), an alpha-adrenergic agent, failed to stimulate GH release in the unanesthetized rat. These results indicate that the GH-releasing actions of opiatergic and alpha-adrenergic mechanisms are mediated through stimulation of endogenous rhGRF release in the rat.
D000818:Animals; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin / Q000494:pharmacology; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000276:immunology / Q000378:metabolism*; D007106:Immune Sera; D008297:Male; D010446:Peptide Fragments / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000378:metabolism*
D007106:Immune Sera; D010446:Peptide Fragments; D011942:Receptors, Adrenergic, alpha; C036893:somatotropin releasing factor 40; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone