Developmental exposure to endocrine disruptor chemicals alters follicular dynamics and steroid levels in Caiman latirostris

STOKER C; BELDOMENICO PM; BOSQUIAZZO VL; ZAYAS MA; REY F; RODRIGUEZ HA; MUÑOZ DE TORO M; LUQUE EH

GENERAL AND COMPARATIVE ENDOCRINOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2008 vol. 156 p. 603 - 612

0016-6480

Human and wildlife are exposed to endocrine disruptor chemicals (EDC). The exposure at critical periods of development may be responsible for reproductive disorders in adults. To test the hypothesis that in ovum exposure to environmentally relevant doses of EDC at a critical period for gonadal organogenesis alters post-hatching folliculogenesis and steroidogenesis in Caiman latirostris, we studied the impact of in ovum exposure to 17b-estradiol (E2), bisphenol A (BPA), endosulfan (END) and atrazine (ATZ) on gonadal differentiation, follicular dynamics and circulating levels of steroid hormones in neonatal and juvenile caimans. Since C. latirostris is a species with temperature dependent sex determination, eggs were incubated at male (33ºC) or female (30ºC) producing temperatures and the effect of EDC was evaluated. Neonatal ovaries exhibited germ cells mainly located in clusters evidencing proliferative activity and type I to III follicles. Juvenile ovaries exhibited germ cells and advanced stages of previtellogenic follicles. Prenatal exposure to the higher doses of E2 (1.4 ppm) or BPA (140 ppm) overrode the temperature effect on sex determination. Neonatal females produced by sex reversion lacked type III follicles, while females prenatally exposed to the lowest doses of E2 (0.014 ppm) and BPA (1.4 ppm) or ATZ (0.2 ppm) showed an increase in type III follicles. Juvenile caimans prenatally exposed to E2 or BPA showed an augmented incidence of multioocyte follicles. Neonatal females caimans exposed in ovum to E2 or BPA had higher estrogen serum levels whereas exposure to E2, BPA, ATZ and END decreased T levels. Present data demonstrates that exposure to EDC during gonadal organogenesis alters follicular dynamics and steroid levels later in life. These effects might have an impact on caiman fertility.