Effect of L-tryptophan on apomorphine-induced growth hormone secretion in normal subjects.
Oral administration of the serotonin precursor, L-tryptophan, to normal male volunteers (n = 7) in a dose (3 g) sufficient to increase free plasma tryptophan concentrations more than 12-fold had no significant effect on basal growth hormone secretion or on apomorphine HCL-induced (0.75 mg sc) peak growth hormone concentrations. These data suggest that, in man, tryptophan administration has little effect on central dopaminergic function, at least in the hypothalamic-pituitary axis and that serotonergic mechanisms have no major modulatory effect on dopamine-mediated growth hormone secretion.
D000328:Adult; D001058:Apomorphine / Q000494:pharmacology*; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011954:Receptors, Dopamine / Q000187:drug effects; D014364:Tryptophan / Q000097:blood / Q000494:pharmacology*
D011954:Receptors, Dopamine; D014364:Tryptophan; D013006:Growth Hormone; D001058:Apomorphine