精子DNA单双链损伤与精子浓度的关系研究

摘要

Objectives:To study the relationship between sperm nuclear DNA damage and sperm production,and to explore the pathogenesis of oligospermia.Methods:120 male infertile patients,aged between 25-40 years,were selected.According to the world health standard for routine examination of semen,sperm concentration and motility were analyzed.Two tailed comet assay analysis was used to analyze sperm DNA single and double strand damage index.Results:120 male infertile patients,according to the sperm concentration,were divided into three study groups,group 1 (sperm concentration ＜ 10 x 106ml-1),group 2 (10 x 106ml-1 ＜ sperm concentration ＜ 20 x 106ml-1) and group 3 (sperm concentration ＞ 20 x 106 ml-1),with 40 cases in each group.Age,sperm motility and sperm deformity rate among the 3 groups had no significant difference.In group 1,sperm DFI was (59.48 ± 15.21) ％,SSB-DFI was (25.86 ± 11.86) ％,SSB-DFI/DFI was (43.31 ± 13.72) ％,DSB-DFI was (31.93 ± 10.21)％,DSB-DFI/DFI was (53.85 ± 10.27)％;in group 2,sperm DFI was (3.402 ±1.77) ％,SSB-DFI was (26.71 ± 3.45) ％,SSB-DFI/DFI was (78.59 ± 9.78) ％,DSB-DFI was (8.37 ±3.04) ％,DSB-DFI/DFI was (2.14 ± 9.79) ％;in group 3,sperm DFI was (20.77 ± 243) ％,SSB-DFI was (20.44 ± 2.39) ％,SSB-DFI/DFI was (98.44 ± 2.87) ％,DSB-DFI was (1.32 ± 0.61) ％,DSB-DFI/DFI was (1.55 ± 2.87) ％.SSB-DFI among three groups had no significant difference (P ＞ 0.05).SSB-DFI/DFI among three groups gradually increased with the sperm concentration increase (P ＜ 0.05).DSB-DFI gradually decreased with sperm concentration increase (P ＜ 0.05).DSB-DFI/DFI gradually decreased with sperm concentration increase (P ＜ 0.05).SSB-DFI and SSB-DFI/DFI had no correlation (P ＞ 0.05) with conventional semen parameters.Sperm DSB-DFI and DSB-DFI/DFI had negative correlation with sperm concentration (P ＜ 0.05).Conclusion:The higher the levels of DSB-DFI and DSB-DFI/DFI are,the lower sperm concentration is.Sperm DNA double chain injury may be the real reason for low sperm concentration.%目的:研究男性不育患者精子浓度与精子DNA单双链损伤的关系,探讨少精症的发生机制.方法:研究对象为120例男性不育患者,年龄25～40岁之间,根据世界卫生标准进行精液常规检测分析精子的浓度、活力等,利用双尾彗星试验分析精子DNA单双链损伤指数.结果:120例男性不育患者根据精子浓度分为三个研究组,即组1(精子浓度＜10×106mL-1)、组2(精子浓度＜20×106mL-1)和组3(精子浓度＞20×106mL-1),每组40例.三组之间年龄、精子活力及精子畸形率没有统计学差异;组1精子DNA损伤指数(DFI)为(59.48±15.21)％,单链损伤指数(SSB-DFI)为(25.86±11.86)％,SSB占所有损伤精子的比率(SSB-DFI/DFI)为(43.31±13.72)％,双链损伤指数(DSB-DFI)为(31.93±10.21)％,DSB占所有损伤精子的比率(DSB-DFI/DFI)为(53.85±10.27)％;组2精子DNA损伤指数(DFI)为(34.02±1.77)％,单链损伤指数(SSB-DFI)为(26.71±3.45)％,SSB占所有损伤精子的比率(SSB-DFI/DFI)为(78.59±9.78)％,双链损伤指数(DSB-DFI)为(8.37±3.04)％,DSB占所有损伤精子的比率(DSB-DFI/DFI)为(21.40±9.79)％;组3精子DNA损伤指数(DFI)为(20.77±2.43)％,单链损伤指数(SSB-DFI)为(20.44±2.39)％,SSB占所有损伤精子的比率(SSB-DFL/DFI)为(98.44±2.87)％,双链损伤指数(DSB-DFI)为(1.32±0.61)％,DSB占所有损伤精子的比率(DSB-DFI/DFI)为(1.55±2.87)％.三组间SSB-DFI无显著差异(P＞0.05),SSB-DFI/DFI在组1、组2和组3间随精予浓度升高而逐渐升高(P＜0.05),DSB-DFI随精子浓度升高而逐渐下降(P＜0.05),DSB-DFI/DFI随精子浓度升高而逐渐下降(P＜0.05).精子SSB-DFI及SSB-DFI/DFI与其他精液常规参数均无相关关系(P＞0.05),精子DSB-DFI及DSB-DFI/DFI与精子浓度呈负相关(P＜0.05).结论:精子DSB-DFI和DSB-DFI/DFI水平越高,精子浓度就越低,精子DNA双链损伤可能是精子浓度低的真正原因.