Transforming growth factor-β (TGF-β) maintains follicular ultrastructure and stimulates preantral follicle growth in caprine ovarian tissue cultured in vitro

The objectives of this study were to investigate whether TGF-beta affect the survival, activation and further growth of goat primordial follicles enclosed in ovarian cortex after in vitro culture. Goat ovaries were collected from an abattoir and pieces of ovarian tissues were cultured for one or seven days in a supplemented alpha Minimum Essential Medium, alone or containing TGF-beta (1, 5, 10 or 50ng/mL). Ovarian tissues from the fresh control as well as those cultured were processed for histological and ultrastructural studies. The results showed that when compared with fresh control, there was decrease in the percentages of histologically normal follicles in all treatments only after seven days culture. TGF-beta did not affect the activation of preantral follicles regardless of its concentration, however, larger follicles diameter (P<0.05) was observed using 10 ng/mL TGF-beta than in the fresh control and other treatments. Moreover, this concentration maintained the normal ultrastructure after seven days of culture. In conclusion, TGF-beta showed additional effect on the follicle growth and the maintenance of ultrastructural integrity of goat preantral follicles enclosed in ovarian tissue when used at 10 ng/mL during seven days of culture.