褪黑素对丙烯酰胺致大鼠睾丸细胞DNA损伤的拮抗作用

目的研究丙烯酰胺(AA)致大鼠睾丸细胞DNA损伤及褪黑素(MT)对损伤的拮抗作用。方法 40只8周龄SD雄鼠,随机分为空白对照组、MT组、AA组和MT+AA组,每组10只。MT(10 mg.kg-1.d-1)腹腔注射,AA(25 mg.kg-1.d-1)经口灌胃染毒,共30 d。单细胞凝胶电泳检测睾丸细胞DNA损伤(CASP软件测定慧星尾长、慧尾DNA百分含量、尾矩及Olive尾矩),TUNEL标记凋亡细胞,ELISA试剂盒检测睾丸组织中8-羟基脱氧鸟苷(8-OHdG)含量,硫代巴比妥酸法测定丙二醛(MDA)水平,黄嘌呤氧化酶法测定超氧化物歧化酶(SOD)活力。结果与对照组比较,AA组大鼠睾丸细胞彗星尾长、彗尾DNA百分含量、尾矩、Olive尾矩均显著增加,凋亡细胞增多,睾丸组织8-OHdG和MDA含量增加,SOD活力降低,差异均有统计学意义(均P<0.05)。与AA组比较,MT+AA组大鼠睾丸细胞DNA损伤程度减轻,凋亡细胞数减少,睾丸组织8-OHdG和MDA含量降低,SOD活力升高,差异均有统计学意义(均P<0.05)。结论 AA能够引起大鼠睾丸细胞DNA损伤并诱发凋亡,且对睾丸产生氧化损伤;MT则能拮抗AA引起的损伤。氧化损伤可能是AA引起大鼠睾丸细胞DNA损伤的机制之一。

Effect of melatonin on acrylamide-induced DNA damage in rat testicular cells

Objective To investigate the protective effects of melatonin(MT) on acrylamide(AA)-induced DNA damage in rat testicular cells.Methods Forty male SD rats aged 8 weeks were randomly divided into blank control group,MT group,AA group and MT+AA group,with 10 rats in each group.MT was intraperitoneally injected at the dose of 10 mg·kg-1·d-1,AA was orally administrated at the dose of 25 mg·kg-1·d-1,and the treatment lasted for 30 d.Comet assay and Comet Assay Software Project were employed to examine the DNA damage(comet tail length,tail DNA%,tail moment and Olive tail moment) of testicular cells,TUNEL was used to detect the cell apoptosis,the levels of 8-hydrxydeoxyguanosine(8-OHdG) in testis tissues were measured by ELISA,the levels of malondialdehyde(MDA) were measured by thiobarbituric acid method,and the activity of superoxide dismutase(SOD) was determined by xanthine oxidase method.ResultsCompared with blank control group,the comet tail length,tail DNA%,tail moment and Olive tail moment in testicular cells significantly increased,the number of apoptotic cells significantly increased,the levels of 8-OHdG and MDA in testis tissues significantly increased,and the activity of SOD significantly decreased in AA group(P<0.05).Compared with AA group,the DNA damage of testicular cells significantly decreased,the number of apoptotic cells significantly decreased,the levels of 8-OHdG and MDA in testis tissues significantly decreased,and the activity of SOD significantly increased in MT+AA group(P<0.05).Conclusion AA could induce DNA damage and apoptosis in rat testicular cells,and cause oxidative damage in testis.However,MT could prevent the alterations caused by AA.Oxidative damage is probably one of the mechanisms of AA-induced DNA damage in rat testicular cells.