香烟烟雾对雄性大鼠睾丸组织代谢酶的毒性研究

Toxicity of cigarette smoke to metabolic enzymes in testicular tissues of male rats

[背景]香烟烟雾中含有多种致癌物质和诱变剂,可能对男性生殖系统产生不利的影响。烟草可以通过直接影响睾丸及其功能,使生精能力下降以及改变精子功能状态,从而降低男性生育能力。雄性大鼠睾丸组织中碱性磷酸酶(AKP)、γ-谷氨酰转肽酶(γ-GT)、β葡糖醛酸糖苷酶(β-GD)和葡萄糖-6-磷酸脱氢酶(G-6-PD)的活力与雄性大鼠生殖健康有关。[目的]探讨香烟烟雾对雄性大鼠睾丸组织中AKP、γ-GT、β-GD、G-6-PD活力的影响。[方法]SPF级成年健康SD雄性大鼠200只,随机分成对照组、低剂量染毒组(10支香烟/d)、中剂量染毒组(20支香烟/d)、高剂量染毒组(30支香烟/d),分别染毒2、4、6、8、12周,共20个亚组,每个亚组10只。实验组采用呼吸道静式染毒,在染毒柜内每天进行一次香烟烟雾暴露染毒,每次30 min,对照组不参与染毒实验外,其余处理与染毒组相同。每个染毒周的最后一天,测定各组大鼠的体重,处死大鼠,取睾丸和附睾观察其形态,测量睾丸和附睾的重量,计算脏器系数,测定睾丸组织中AKP、γ-GT、β-GD、G-6-PD的活力。[结果]随着染毒剂量的增加,大鼠体重增长缓慢,高剂量组大鼠体重出现明显的降低,暴露剂量和暴露时间存在交互效应(P<0.01)。大鼠睾丸和附睾重量及其脏器系数没有明显的变化,但是暴露剂量和暴露时间存在交互效应(P<0.01)。睾丸组织病理学结果显示,随着染毒剂量的增加,曲细精管出现不同程度的病理损伤。中、高剂量组AKP的活力低于同期对照组(P<0.05),暴露剂量和暴露时间不存在在交互效应(P>0.05);第4周开始中、高剂量组γ-GT的活力出现降低(P<0.05),且暴露剂量和暴露时间存在交互效应(P<0.01);各染毒剂量组β-GD的活力从第6周开始低于同期对照组(P<0.05),且暴露剂量和暴露时间存在交互效应(P<0.01);中、高剂量组的G-6-PD活力从第4周开始低于同期对照组(P<0.05),且暴露剂量和暴露时间存在交互效应(P<0.01)。[结论]香烟烟雾可改变AKP、γ-GT、β-GD、G-6-PD的活力,引起睾丸组织损伤。

[Background]Cigarette smoke contains a variety of carcinogens and mutagens,which may adversely affect male reproductive system.Tobacco can reduce spermatogenesis and alter sperm function by directly affecting the testis and their functions,thereby reducing male fertility.The activities of alkaline phosphatase(AKP),γ-glutamyl transpeptidase(γ-GT),β-glucuronidase(β-GD),and glucose-6-phosphate dehydrogenase(G-6-PD)in the testis are closely related to the reproductive health of male rats.[Objective]The purpose of this in vivo experiment is to explore the effects of cigarette smoke on AKP,γ-GT,β-GD,and G-6-PD enzymatic activities in the testis of male rats.[Methods]Two hundred males SPF SD rats were randomly divided into control group(no cigarette exposure),low dose group(10 cigarettes a day),medium dose group(20 cigarettes a day),and high dose group(30 cigarettes a day),and the administration lasted for 2,4,6,8,and 12 weeks,respectively.There were a total of 20 subgroups,with 10 rats in each subgroup.The experimental groups were exposed to tobacco smoke by static inhalation in an exposure cabinet once a day,30 min each time.The control group did not participate in the exposure,and the rest of treatment was the same as the exposure groups.On the last day of each exposure week,the rats were weighed and then sacrificed.The morphology of testis and epididymis was observed,the weights and organ coefficients of testis and epididymis were weighed and calculated,and the activities of AKP,γ-GT,β-GD,and G-6-PD in testicular tissues were measured.[Results]With the increase of treatment dose,the weight growth of the rats was slower,the body weight of rats in the high dose group was significantly reduced,and there was an interaction effect between exposure dose and exposure time(P<0.01).There were no significant changes in rat testis and epididymis weights and organ coefficients,but there was an interaction effect between exposure dose and exposure time(P<0.01).The testicular histopathology test results showed that with the increase of exposure dose,seminiferous tubules presented different degrees of pathological damage.The activities of AKP in the medium and high dose groups were lower than that in the control group(P<0.05),and there was no interaction effect between exposure dose and exposure time(P>0.05).The activities ofγ-GT were reduced in the medium and high dose groups since week 4(P<0.05),and there was an interaction effect between exposure dose and exposure time(P<0.01).The activities ofβ-GD of all exposed groups were lower than that of the control group of the same period from week 6(P<0.05),and there was an interaction effect between exposure dose and exposure time(P<0.01);the activities of G-6-PD in the medium and high dose groups also presented the same pattern since week 4(P<0.05),and there was the same interaction effect between exposure dose and exposure time(P<0.01).[Conclusion]Cigarette smoke can alter the activities of AKP,γ-GT,β-GD,and G-6-PD,causing testicular tissue damage.