Abstract: To investigate the effects of antioxidant NacetylLcysteine(NAC) on the fetal ovarian tissues cultured in vitro. Methods: Fetal ovaries of 20 to 28 weeks were cultured for 0 to 9 days in 4 NAC groups: 25?mmol/L, 50?mmol/L, 100?mmol/L and 0?mmol/L. The concentrations of estrogen in the culture medium were measured by radioimmunoassay and the morphologic changes of the cultured ovarian tissues were observed. Results: The proportion of matured follicles of different stages in the 3 experimental groups were significantly different compared with the control group (P<0.05) and the estrogen output in both control and experimental groups were significantly increased with the time prolonged(P＜0.05), however, the differences among the experimental groups were not significant　(P>0.05); the estrogen output of the fetal ovarian tissues in the 3 experimental groups were significantly increased than that in the control group (P<0.05), however, the differences among the experimental groups were not significant (P>0.05). Conclusion: NacetylLcysteine can increase the estrogen output and the proportion of mature follicles in the fetal ovarian tissues cultured in vitro.

Key words: Ovary, Fetus, NacetylLcysteine