Oral 5 hydroxytryptophan (5 HTP) administration, either 200 mg acutely or 50 mg q.i.d. for 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 hydroxylated 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.
|Number of pages||5|
|Publication status||Published - 1976|
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