Failure of oral 5-hydroxytryptohan administration to affect prolactin secretion in man.
Oral 5-hydroxytryptopahn (5-HTP) administration, either 200 mg acutely or 50 mg q.i.d. fr 3 days plus 200 mg acutely, failed to modify either basal or TRH-stimulated prolactin secretion in normal subjects. This is at variance with the stimulatory action of intravenous tryptophan on human prolactin release. However, it is doubtful that 5-HTP at the dose used may increase brain serotonin concentration; moreover, the hydroxlated amino acid is also taken up by catecholaminergic neurons, from which noradrenaline and dopamine may then be released. It is concluded that the failure of 5-HTP to affect prolactin secretion in man is not a proof against the existence of serotoninergic stimulatory influences on human prolactin release.
D006916:5-Hydroxytryptophan; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D011388:Prolactin / Q000097:blood*; D013973:Thyrotropin-Releasing Hormone
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D006916:5-Hydroxytryptophan