Zinc supplementation does not inhibit basal and metoclopramide-stimulated prolactinemia secretion in healthy men.
Dopamine (DA) and zinc (Zn++) share common mechanisms in their inhibition of prolactin (PRL) secretion. Both substances are present in the same brain areas, where Zn++ is released together with DA, suggesting a modulatory effect of Zn++ on dopaminergic receptors. The aim of the present study was to evaluate the effect of Zn++ supplementation on basal and PRL secretion stimulated by metoclopramide (MCP), a dopaminergic antagonist. Seven healthy men were evaluated in controlled study, where MCP (5 mg) was given intravenously, before and after 3 months of oral Zn++ (25 mg) administration. Our results indicate that chronic Zn++ administration does not change basal or MCP-stimulated plasma PRL secretion suggesting that, in humans, Zn++ does not interfere on PRL secretion mediated through dopaminergic receptors.
Castro
Ana V B
AV
Unidade de Endocrinologia e Metabologia, Faculdade de Medicina, UNESP, Botucatu-São Paulo, Brasil.
Mendonça
Berenice B
BB
Bloise
Walter
W
Shuhama
Tadao
T
Brandão-Neto
José
J
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D018492:Dopamine Antagonists / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008787:Metoclopramide / Q000494:pharmacology*; D010919:Placebos; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood*
D018492:Dopamine Antagonists; D010919:Placebos; D011388:Prolactin; D015032:Zinc; D008787:Metoclopramide