N-乙酰半胱氨酸对外源性H_2O_2和内源性O_2^-引起的精子DNA损伤的保护作用

The Protective Effects of N-Acetylcysteine on Exogenous Hydrogen Peroxide and Endogenous Superoxide Anion-induced DNA Strand Breakage in Human Spermatozoa

目的 :用精子单细胞凝胶电泳 ( SCGE)实验方法检测 N-乙酰半胱氨酸体外条件下对外源性 H2 O2 和内源性 O2 -引起的精子 DNA损伤的保护作用。方法 :精子分别用 0 .5mmol/ L H2 O2 和 5.0 mmol/ Lβ-NADPH处理的同时分别加入不同浓度 ( 0 .1～ 1 mmol/L )的 N-乙酰半胱氨酸 ,用单细胞凝胶电泳 ( SCGE)检测各组精子中慧星细胞百分率并比较各组平均慧星尾长的差异。结果 :精子细胞用 0 .5mmol/ L H2 O2 处理的同时加入不同浓度 ( 0 .1～ 1 mmol/ L)的 N-乙酰半胱氨酸 ,与单纯用 0 .5mmol/ L H2 O2 处理组比较 ,慧星细胞百分率明显减少 ,平均慧尾显著缩短 ;精子细胞用 5.0 mmol/ Lβ-NADPH处理的同时加入不同浓度 ( 0 .1～ 1 mmol/ L)的 N-乙酰半胱氨酸 ,与单纯用 5.0 mmol/ Lβ-NADPH处理组比较 ,平均慧尾长度显著缩短 ,但慧星细胞百分率无显著性差异。结论 :N-乙酰半胱氨酸对 0 .5mmol/ L外源性 H2 O2 引起的精子 DNA损伤有明显保护作用 ,而对 5.0 mmol/ Lβ-NADPH诱导的内源性 O2 - 引起的精子 DNA损伤的保护作用不明显。

Objective: To study the protective effects of N-Acetylcysteine(NAC) on exogenous hydrogen peroxide and endogenous superoxide anion-induced DNA strand breakage in human spermatozoa in vitro. Methods: NAC of sperm cells were exposed to 0.5 mmol/L of H 2O 2 and 5.0 mmol/L of β-NADPH without or with 0.1, 0.5, 1.0 mmol/L the single cell gel electropherosis respectively (SCGE) respectively. The percentage of sperm comet cells and the comet tail length were measured by using SCGE. Results: The percentage of sperm comet cells and the comet tail length in the sperm cells exposed to H 2O 2 decreased significantly in a dose-related manner. Although NAC decreased the comet length in sperm cells exposed to β-NADPH significantly, there was no significant difference in the percentage of the sperm comet cells between the sperm cells exposed to β-NADPH with NAC and those exposed to β-NADPH without NAC. Conclusion: NAC has a protective effect on exogenous hydrogen peroxide-induced DNA damage. Whereas, it seems to be ineffective on endogenous superoxide-induced DNA strand breaks in sperm cells.