Initial study on the possible mechanisms involved in the effects of high doses of perfluorooctane sulfonate (PFOS) on prolactin secretion.

Perfluorooctane sulfonate (PFOS) is a fluorinated organic compound. This chemical is neurotoxic and can alter the pituitary secretion. This is an initial study aimed at knowing the toxic effects of high doses of PFOS on prolactin secretion and the possible mechanisms involved in these alterations. For that, adult male rats were orally treated with 3.0 and 6.0 mg of PFOS/kg body weight (b.w.)/day for 28 days. At the end of the treatment, the serum levels of prolactin and estradiol as well as the concentration of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and gamma-aminobutyric acid (GABA) were quantified in the anterior and in the mediobasal hypothalamus. PFOS, at the administered doses, reduced prolactin and estradiol secretion, increased the concentration of dopamine and GABA in the anterior hypothalamus, and decreased the ratios DOPAC/dopamine and HVA/dopamine in this same hypothalamic area. The outcomes reported in this study suggest that (1) high doses of PFOS inhibit prolactin secretion in adult male rats; (2) only the periventricular-hypophysial dopaminergic (PHDA) neurons seem to be involved in this inhibitory effect but not the tuberoinfundibular dopaminergic (TIDA) and the tuberohypophysial dopaminergic (THDA) systems; (3) GABAergic cells from the paraventricular and supraoptic nuclei could be partially responsible for the PFOS action on prolactin secretion; and finally (4) estradiol might take part in the inhibition exerted by elevated concentration of PFOS on prolactin release.