an in vitro comparative study of follicle stimulating hormone (fsh) and activin a effects on the maturation of preantral follicle-enclosed oocytes from immature syrian mice

objectives: it was aimed to investigate the effects of different doses of follicle stimulating hormone (fsh) and activin a on the growth and maturation of preantral mouse follicles during the in vitro culture. methods: preantral follicles (90-100 µm in diameter) were harvested from 6-8 week-old syrian mice and cultured in tcm199 culture medium for 6 days to see the effect of fsh and activin a. activin a concentrations in the range of 10-200 ng/ml were used, while 10, 50, 100, 150 and 200 miu/ml fsh were used in the experiment. results: activin a concentration of 100 ng/ml resulted in a significant increase in follicle diameter (170 µm) with the survival rate of 73% as compared to the control (100 µm and 25%, p<0.05). the number of oocytes matured and the percentage of germinal vesicle breakdown (gvbd) was 61 and 70%, respectively as compared to the control (20 and 29%, p<0.05). follicle diameter (190 µm) and survival rate (85%) increased significantly in the presence of 100 miu/ml of fsh as compared to the control (p<0.05). but, the administration of activin a+fsh increased the effect of both factors on follicular diameter (205 µm as compared to 100 µm in control, p<0.01). follicle survival, oocyte maturation and gvbd rates were 91, 81 and 89%, respectively (p<0.01). conclusion: these results have suggested that exposure to fsh and activin a before the formation of antral cavity had positive effect on follicle survival and oocyte robustness.