Short-term exposure to bisphenol A affects water and salt intakes differently in male and ovariectomised female rats.

Thirst and sodium appetite are motivational states that lead to the search for and ingestion of water and sodium, thus contributing to maintenance of hydromineral balance. Oestrogens affect fluid intake and sodium preference. Bisphenol A (BPA) is an environmental endocrine-disrupting substance with oestrogenic activity. Whether there are sex differences in the ingestive effects of BPA is unknown. Therefore, the aim of the present work was to determine the effect of short-term treatment of low doses of BPA on thirst and sodium appetite in adult male and ovariectomised Wistar rats. Rats were subcutaneously injected with either vehicle or 10, 50, 100, or 500 μg/kg/day BPA for a week. Two-bottle tests (water and 2.7% NaCl solution) were conducted in the animals' home cages with and without 24 h water deprivation. BPA reduced water and 2.7% NaCl intakes in a sex-dependent-manner. Fluid intakes displayed inverted U-shaped dose-response curves, with different dose dependencies in spontaneously drinker rats than after 24 h water deprivation dehydration. Future studies on the role of BPA in sex-dependent body fluid homeostasis should elucidate the effects of BPA on the neuroendocrine controls of thirst and salt appetite.