Zinc supplementation does not inhibit basal and metoclopramide-stimulated prolactinemia secretion in healthy men
Journal of Trace Elements In Medicine and Biology. Jena: Urban & Fischer Verlag, v. 16, n. 2, p. 69-73, 2002.
Universidade Federal do Rio Grande do Norte (UFRN)
Universidade de São Paulo (USP)
Universidade Estadual Paulista (Unesp)
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.