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

STOKER C, BELDOMÉNICO PM, BOSQUIAZZO VL, ZAYAS MA, REY F, RODRÍGUEZ H, MUÑOZ-DE-TORO M, LUQUE EH.

GENERAL AND COMPARATIVE ENDOCRINOLOGY

Año: 2008 vol. 156 p. 603 - 612

0016-6480

Human and wildlife are exposed at critical periods of development to endocrine disruptor chemicals (EDC) that may be responsible for reproductive disorders. To test the hypothesis that in ovum exposure to 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 17beta-estradiol (E(2)), bisphenol A (BPA), endosulfan (END) and atrazine (ATZ) on gonadal differentiation, follicular dynamics and circulating levels of steroid hormones in neonatal and juvenile caiman. Since C. latirostris is a species with temperature dependent sex determination, eggs were incubated at male (33 degrees C) or female (30 degrees C) 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 pre-vitellogenic follicles. Prenatal exposure to the highest doses of E(2) (1.4ppm) or BPA (140ppm) overrode male temperature effect on sex determination. Neonatal females produced by sex reversion lacked type III follicles, while females prenatally exposed to the lowest doses of E(2) (0.014ppm) and BPA (1.4ppm) or ATZ (0.2ppm) showed an increase in type III follicles. Juvenile caiman prenatally exposed to E(2) or BPA showed an augmented incidence of multioocyte follicles. Neonatal female caiman exposed in ovum to E(2) or BPA had higher estrogen serum levels whereas exposure to E(2), 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.