Involvement of growth hormone (GH)-releasing factor in GH secretion induced by serotoninergic mechanisms in conscious rats.
A possible role of hypothalamic GH-releasing factor (GRF) in GH secretion induced by serotoninergic stimuli was investigated in conscious freely moving rats with a passive immunization technique. Either iv injection of 5-hydroxy-L-tryptophan (1 mg/100 g BW) or intracerebroventricular injection of serotonin (10 micrograms/rat) caused an increase in plasma GH in rats treated with normal rabbit serum (0.5 ml/rat, iv) 30 min previously. Injection of rabbit antiserum specific for rat GRF (0.5 ml/rat, iv, 30 min previously) blunted the plasma GH increase induced by 5-hydroxy-L-tryptophan or serotonin in these animals. These results suggest that GH secretion induced by serotoninergic mechanisms is mediated, at least in part, by hypothalamic GRF in the rat.
D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000818:Animals; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000502:physiology*; D007031:Hypothalamus / Q000187:drug effects; D007106:Immune Sera; D007116:Immunization, Passive; D007276:Injections, Intraventricular; D011817:Rabbits; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*
D007106:Immune Sera; D012701:Serotonin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D006916:5-Hydroxytryptophan