Estrogenic and antiestrogenic effect of in vitro treatment of follicular cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin

Objective. Two types of follicular cells from preovulatory ovary were cultured in vitro separately and in co-culture to test difference in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) action on particular cell types. Methods. The accumulation of TCDD in follicular wall was analysed using coupled capillary gas chromatography–mass spectrometry. Whole preovulatory follicles were isolated from ovary and incubated with prolonged exposure to 0.1 nM TCDD or single exposure to 10 nM TCDD for four days. In the second part of experiments direct effects of TCDD on steroidogenesis were investigated in porcine theca cells (Tc) and granulosa cells (Gc) cultured alone and in co-culture (GT). The media were collected after four days for steroid analysis. Results. 59.3% and 81.2% of TCDD added to the culture medium was accumulated after 0.1 and 10 nM, respectively. TCDD in a dose-dependent manner increased estradiol secretion with concomitant progesterone secretion by theca interna cells. On the other hand decrease of both progesterone and estradiol secretion by granulosa cells cultured alone and in co-culture with theca cells was noted. Conclusion. Different cell-specific estrogenic or antiestrogenic effect of TCDD were found in ovarian follicles