EXPOSURE TO BISPHENOL A ALTERS THE HYPOTHALAMIC-PITUITARY-THYROID AXIS IN FEMALE RATS

FERNANDEZ MO; LUX-LANTOS VAR; LIBERTUN C

Chascomús, Pcia. Bs Aires.

Jornada; XVI Jornadas Anuales de la Sociedad Argentina de Biologia; 2014

Sociedad Argentina de Biologia

Bisphenol A (BPA) is a monomer of polycarbonate plastics and a constituent of epoxy and polyestirene resins used in industry. Profound in-vivo effects of BPA have been described on the hypothalamic-pituitary unit, in different animal species. We studied the effects of BPA on the hypothalamic-pituitary-thyroid axis. We used two experimental models, an in-vivo and an in-vitro model. In the in-vivo model, Sprague-Dawley (SD) female rats were exposed neonatally (from days 1 to 10 of life) to different doses of BPA (500, 50, or, in some cases, 5 ìg) or vehicle as control. The in-vitro model consisted of primary pituitary cultures (PPC) from 13-day old or adult SD females. Neonatal exposure to BPA did not alter serum TSH in 13-day old females, but it did in adulthood, with TSH levels higher in animals treated with 50 ìg of BPA (B50). Serum T3 and T4 levels were lower in the 500 ìg-treated animals and T4 in 5 ìg-treated animals. PPCs obtained from B50 adult females released more TSH than the Controls. In PPCs from normal 13-day old females, pretreatment with BPA or estradiol (1.10^-7 M) increased TSH release and lowered the response to TRH. The results show that neonatal exposure to BPA alters the hypothalamic-pituitary-thyroid axis in adulthood, and that BPA has direct actions in the pituitary. (CONICET-UBA-ANPCYT).