Effect of hypothalamic surgery on prolactin release induced by 5-hydroxytryptophan (5-HTP) in rats.
Intravenous injections of varying doses of 5-HTP (1, 3 and 5 mg/100 g body wt), a precursor of serotonin, caused a significant and dose-related increase in plasma prolactin concentrations in urethane-anesthetized rats. Increases in plasma prolactin concentrations caused by 5-HTP (1 mg/100 g body wt iv) were abolished by the concomitant administration of L-DOPA (2 mg/100 g body wt iv). Plasma prolactin levels were also significantly elevated following the injection of 5-HTP in rats with complete hypothalamic deafferentation, whereas 5-HTP had no significant effect on plasma prolactin levels in rats with extensive hypothalamic ablation. These results suggest that 5-HTP causes prolactin secretion by stimulating the serotoninergic mechanism in the hypothalamus.
D006916:5-Hydroxytryptophan / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002746:Chlorpromazine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007031:Hypothalamus / Q000601:surgery*; D007275:Injections, Intravenous; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D011388:Prolactin / Q000097:blood*; D051381:Rats
D007980:Levodopa; D011388:Prolactin; D006916:5-Hydroxytryptophan; D002746:Chlorpromazine