Role of Follicle Stimulating Hormone in the Survival, Activation and Further Growth of in vitro Cultured Sheep Primordial Follicles

The aim of the present study was to investigate the effect of follicle stimulating hormone (FSH) on survival, activation and growth of ovine primordial follicles using histological studies. Pieces of ovine ovarian cortex were obtained and cultured for 6 days in Minimum Essential Medium supplemented with or without FSH (50 ng/mL). These fragments were then process to be used for histology compared to each other and non-cultured group. The results showed that the lowest percentage of normal follicles in control medium was observed after 6 days of culture. A higher percentage of growing follicles was observed in presence vs. absence of FSH. Moreover, an increase in diameter of both oocyte and follicle was observed in those fragments that have been cultured in presence of FSH. This study demonstrated that FSH not only maintains the morphological integrity of ovine preantral follicles cultured for 6 days in vitro, but also stimulates the activation of primordial follicles and the growth of activated follicles.