en 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 Related Fields Related Fields مقاله کامل Full Length/Original Article 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 &micro;m 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 &micro;m) with the survival rate of 73% as compared to the control (100 &micro;m 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 &micro;m) 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 &micro;m as compared to 100 &micro;m 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. Follicle stimulating hormone (FSH), Oocyte maturation, Follicle, Activin A, Germinal vesicle breakdown (GVBD) 85 92 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-55&slc_lang=en&sid=1 Aisha Javed Amer Jamil No Amer Jamil Aisha Javed No Saeed Rezaei-Zarchi سعید رضایی زارچی No Seyed Mehdi Kalantar سید مهدی کلانتر kalantarsm@ystp.ac.ir Yes Morteza Anvari مرتضی انوری No Habib Nazem حبیب ناظم No