香烟烟雾致睾丸氧化应激损伤与iNOS表达的关系

Correlation Between the Expression of iNOS and Oxidative Stress on Testis After Cigarette Smoke Exposure

目的:探讨诱导型一氧化氮合酶(iNOS)在香烟烟雾致睾丸生殖细胞氧化应激损伤中的关系以及抗氧化治疗的作用。方法:21只8周龄健康雄性SD大鼠制作吸烟染毒模型,随机平均分为3组:对照组(A)、吸烟组(B)、抗氧化治疗组(C)。测定睾丸组织匀浆中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)、一氧化氮(NO)、丙二醛(MDA)、一氧化氮合酶(NOS)及iNOS的含量。结果:吸烟组睾丸组织匀浆SOD、CAT活性增高,GSH-Px活性降低,MDA、NO含量增高,对照组与抗氧化组两者无差别。光镜下见吸烟组睾丸生精小管上皮细胞排列紊乱,生精细胞数量减少,小管腔内精子数量罕见,对照组与抗氧化组两者区别不大。免疫组织化学方法可见吸烟组大鼠睾丸的初、次级精母细胞中iNOS蛋白强阳性表达,在对照组与抗氧化组大鼠睾丸的初、次级精母细胞中iNOS蛋白呈弱阳性表达。结论:吸烟可导致大鼠睾丸氧化应激损伤;iNOS蛋白表达增加可能在吸烟引起睾丸生精上皮细胞氧化应激损伤中发挥重要作用;抗氧化治疗可减少iNOS蛋白在睾丸生精上皮细胞的表达,可减轻吸烟引起睾丸生精上皮细胞的氧化应激损伤。

Objective： To study the relationship of iNOS expression on the rat spermatogenic cells and the oxidative stress after smoking, and to investigate the effects of anti-oxidation therapy. Methods： Twenty-one male rats aged eight weeks were randomizedly and equally divided into three groups. Group A were control group, Group B were exposed to smoking and Group C were exposed to smoking and received daily intramuscular injection of r-GSH. The levels of nitric oxide （NO）, inducible nitric oxidase （iNOS）, nitric oxidase （NOS）, superoxide-dismutase （SOD）, catalase （CAT）, glutathione peroxidase （GSH-Px） ad malondialdehyde （MDA） were studied. The morphology of spermatogenic epithelium in each group was observed with light microscopy. The expression of iNOS protein in epithelium was detected by immunohistochemistry. Results： Activity of SOD and CAT increased but activity of GSH-Px decreased, and levels of MDA and NO increased in testis tissues of rats exposed to smoking （Group B）. The difference between Group A and C was not significant. There was a significant difference of iNOS expression be-tween smoking group and control group, while no difference between Group A and C was found.Conclusion： Exposure to cigarette smoke causes harmful effects in the oxidative enzyme levels in rat testis, iNOS expression probably is more important role in oxidative stress on spermatogenic cells. Anti-oxidative stress therapy could decrease the expession of iNOS on spermatogenic cells, and could reverse the harmful effects of oxidative stress on spermatogenic cells.