Study of Follicle Stimulating Hormone (FSH) Efficiency on the In vitro Growth of Mice Follicles in Presence of Animal Different Sera

Several endocrine and locally acting factors are involved in the complex process of ovarian follicle growth and oocyte maturation. In vitro follicular culture systems, at various developmental stages, allow the identification of these factors and the understanding of their mechanisms of action. Keeping in mind the significance of the influence of environmental factors on the follicle growth, this work focuses on the effect of some endocrine and paracrine factors on the growth and differentiation of preantral follicles during the in vitro follicular culture using the rodent (mouse) model.

Our study was semi-experimental. First task of the study was to choose an appropriate serum type. Prepubertal gilt serum, embryonic stem cell tested fetal calf serum, hypogonadal mouse serum and fetal calf serum were tested during the present study. Effect of the culture period was also evaluated on the follicle growth. After carefully selecting the optimum growth conditions, the effect of FSH was evaluated on the growth and viability of the follicular and oocyte maturation. Different concentrations of FSH (5, 20, 40, 60, 100, 140, 180 and 220 mIU/l) were added to the culture medium (containing 25-30 follicles each) during separate experiments.

After experiments, fetal calf serum (FCS) was chosen for the evaluation of the effect of FSH. During the present experiment, 100 mIU/ml FSH showed highly significant effect on the follicle and oocyte growth. Follicle survival rate also increased (91%) as compared to that grown without this gonadotropin (28%). Oocyte maturation (61%) and germinal vesicle breakdown rates (81%) also showed an increase (p≤0.05).

These results have suggested that the exposure to FSH and FCS before the formation of antrum had a positive effect on the follicle survival and oocyte robustness.