The effect of persistent chlorinated hydrocarbons on the secretion of estradiol and progesterone by bovine granulosa cells in vitro

The role of persistent chlorinated hydrocarbons (PCH) in the reproductive disorders in ruminants is not well documented. In the present study we have examined the effect of these compounds and their metabolites on the secretion of estradiol (E(2)) and progesterone (P-4) by bovine granulosa cells in vitro. Granulosa cells were isolated from large follicles (greater than or equal to 8 mm diameter) by gently washing the internal follicle wall. Aliquots of approximately 4 x 10(5) viable granulosa cells in 0.5 ml medium were cultured at 37 degrees C in an atmosphere of 5% CO2 and 95% air. Granulosa cells were cultured for 96 h in medium containing different concentrations (10(-1)-10(-4) ng/ml) of a PCH combination. Estradiol and progesterone were measured in unextracted granulosa cell culture medium by Enzyme Immunoassay (EIA). The exposure of granulosa cells to a combination of these organochlorine compounds in vitro, results in a slight decrease of estradiol secretion only at the highest studied concentration of the PCH combination. However, the secretion of progesterone by these cells was seriously decreased, even by concentrations found in ovaries from animals kept under natural environmental conditions. The in vitro culture system of granulosa cells from preovulatory follicles may be useful in screening toxic effect of pesticides in animal reproduction.