Estrous cycle dependent changes in steroid secretion by pig ovarian cells in vitro to polychlorinated biphenyl (PCB 153).

OBJECTIVE

To characterize PCB 153 action on the ovary, the direct effect of PCB153 was investigated in vitro using a co-culture of pig granulosa and theca cells collected during different stages of follicular development.

METHODS

The cells were cultured in the absence or presence of 5, 10, 50 or 100 ng/ml of PCB 153. Media were changed after 48, 96 and 144 h and frozen until further estradiol (E2), progesterone (P4) and testosterone (T) analysis.

RESULTS

48 hrs exposure of follicular cells collected from small-size follicles to all the investigated doses of PCB 153 caused statistically significant decrease in progesterone (P4) secretion and at doses of 50 ng and 100 ng/ml in testosterone (T) secretion. No effect on estradiol (E2) secretion was observed. After 96h and 144h exposure to PCB an increase in P4 secretion with concomitant drastic decrease in T secretion and a tendency to decrease in E2 secretion was observed. Similarly as in the case of small follicles, the action of PCB on steroid secretion by cells collected from medium follicles depended on time of exposure. The increase in T secretion and no influence on P4 and E2 secretion was observed after 2 days of exposure to PCB. Antiestrogenic action of PCB was noted after 4 and 6 days of exposure to PCB. In large, preovulatory follicles 2 days exposure to PCB had no effect on steroids secretion while longer exposition to this congener caused statistically significant antiestrogenic action.

CONCLUSION

The presented paper suggests various actions of PCB 153 as an endocrine disrupter on estradiol, progesterone and testosterone secretion from ovarian cells in vitro which were dependent on both exposure length and stage of the follicular development.