褪黑素对邻苯二甲酸(2-乙基己基)酯致雄性小鼠生殖细胞DNA损伤的拮抗作用

Antagonism of Melatonin against Di-( 2-ethylhexyl)Phthalate-induced DNA Damage in Mice Testicular Cells

目的探讨邻苯二甲酸(2-乙基己基)酯(DEHP)致小鼠睾丸细胞DNA损伤及褪黑素(MT)对此损伤的拮抗作用。方法将40只CL57BL/6J雄性小鼠随机分为4组,包括对照组、MT组、DEHP组和MT+DEHP联合组。MT采用腹腔注射(剂量为15 mg·kg-1),DEHP灌胃染毒(染毒剂量为1000 mg·kg-1),每天染毒1次,连续30 d。检测睾丸组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活力和丙二醛(MDA)、8-羟基脱氧鸟嘌呤(8-OHd G)含量。单细胞凝胶电泳(彗星实验)检测睾丸细胞DNA损伤,慧星图像软件测定慧星尾长、慧尾DNA百分含量、尾矩及Olive尾矩。结果与对照组比较,DEHP组小鼠睾丸组织GSH-Px和SOD活力降低,MDA和8-OHd G含量增加,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,差异均有统计学意义(P<0.05);与DEHP组比较,MT+DEHP联合组小鼠睾丸组织GSH-Px和SOD活力升高,MDA和8-OHd G含量降低,睾丸细胞DNA损伤程度减轻,差异均有统计学意义(P<0.05)。结论 DEHP造成小鼠睾丸明显的氧化应激,并引起睾丸细胞DNA的损伤;MT可拮抗因DEHP染毒导致的睾丸氧化损伤。

Objective To investigate the antagonistic effect of melatonin against di-（ 2-ethylhexyl） phthalate（ DEHP）-induced DNA damage in mice testicular cells. Methods A total of forty CL 57 BL /6J mice were randomly divided into 4groups： control（ saline） group,MT（ melatonin） treated group,DEHP treated group and MT ＋ DEHP treated group. MT was intraperitoneally injected at the dose of 15 mg·kg- 1,and DEHP was orally administrated at the dose of 1000 mg·kg- 1for 30 days. Subsequently,the activities of testicular glutathione peroxidase（ GSH-Px）,superoxide dismutase（ SOD）,the content of testicular malondialdehyde（ MDA） and 8-hydrxydeoxyguanosine（ 8-OHd G） were measured. The comet assay was applied to measure the DNA damage. Comet Assay Software Project was conducted to analyze the DNA damage（ comet tail length,tail DNA%,tail moment and Olive tail moment） of testicular cells. Results Compared with the control group,the contents of MDA and 8-OHd G in testis tissues were significantly increased; and the activities of GSH-Px and SOD were significantly decreased（ P〈0. 05）; the comet tail length,the percentage of tail DNA,tail moment and Olive tail moment in testicular cells were significantly increased in DEHP group（ P〈0. 05）. Compared with the DEHP group,the contents of MDA and 8-OHd G in testis tissues were significantly decreased,the activities of GSH-Px and SOD were significantly increased（ P〈0. 05）; and the DNA damage of testicular cells significantly decreased in MT ＋ DEHP group（ P〈0. 05）.Conclusion DEHP could cause oxidative stress in testis,and induce DNA damage in mice testicular cells. MT could antagonize DEHP-induced oxidative damage in testis of mice.