Evidence for a dopaminergic involvement in the inhibitory effect of alpha human natriuretic peptide on prolactin in man.
Recently, it has been suggested that Atrial Natriuretic Peptides (ANP), as well as peripheral hormones, may have a role as central neurotransmitters or neuromodulators, and in humans it has been observed that alpha human ANP inhibits prolactin secretion. In this study, on 12 normal adult males, we evaluated the effects of ANP on the prolactin release induced by TRH and by the dopaminergic blocker sulpiride. Alpha-hANP administration was followed by a significant fall of prolactin plasma levels but did not influence TRH-induced prolactin response. Nevertheless, sulpiride-induced prolactin secretion was significantly lower after Alpha-hANP administration than after placebo pre-treatment (p values ranging between 0.01 and 0.001). Our results suggest that in man Alpha-hANP has no direct influence on lactotrope cells in inhibiting prolactin secretion, but seems to involve activation of the hypothalamic dopaminergic system.
Foresta
C
C
Istituto di Semeiotica Medica, Catterdra di Patologia Medica III, Università degli Studi di Padova, Italy.
De Carlo
E
E
Mioni
R
R
Zorzi
M
M
Scandellari
C
C
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D004298:Dopamine / Q000502:physiology*; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D011897:Random Allocation; D013469:Sulpiride / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
D010446:Peptide Fragments; D013973:Thyrotropin-Releasing Hormone; D013469:Sulpiride; D009320:Atrial Natriuretic Factor; D011388:Prolactin; D004298:Dopamine