Development of Mouse Preantral Follicle After in Vitro Culture in A Medium Containing Melatonin

Objective: improvements in cancer treatment have allowed more young women to survive.however, many cancer patients suffer from ovarian failure. cryopreservation is oneof the solutions for fertility restoration in these patients. the cryopreservation of isolatedfollicles is a more attractive approach in the long term. many endocrine and paracrinefactors can stimulate the granulosa cells of preantral follicles to proliferate. melatonin actsas direct free radical scavenger and indirect antioxidant. in this study, we investigated thedirect effects of melatonin on follicle development and oocyte maturation by exposing invitro cultured mouse vitrified-warmed ovarian follicles to melatonin.materials and methods: in an experimental study, preantral follicles with diameter of150-180 ?m were isolated from prepubertal mouse ovaries. follicles were vitrified andthawed using cryolock method. they were then cultured individually for 7 days in dropletssupplemented with 0, 10 and 100 pm melatonin, while ovulation was induced using epidermalgrowth factor (egf) and human chorionic gonadotropin (hcg). the survival rate offollicles and nuclear maturation of ovulated oocytes were determined.results: at the end of culture, significant increases in follicle survival (p < 0.001) and in diameter(p < 0.05) were noticed in 10 pm melatonin group compared to control group. in the 100pm group, survival rate was not affected by melatonin. it was revealed that after induction ofovulation, total number of metaphase ii oocytes in treatment groups were not influenced bymelatonin (p > 0.05).conclusion: culture of mouse vitrified-warmed preantral follicles in a medium supplementedwith 10 pm melatonin increased the number of surviving follicles.