2,3,7,8-四氯二苯并二噁英和Aroclor 1254对大鼠睾丸的单独和联合毒性效应

为了探讨2,3,7,8-四氯二苯并二噁英(TCDD)和Aroclor1254对大鼠睾丸的单独和联合毒性效应,采用2×2析因设计将SD大鼠随机分为4组,即对照组、Aroclor1254单独染毒组(10mg·kg-1)、TCDD单独染毒组(10μg·kg-1)和联合染毒组(TCDD10μg·kg-1+Aroclor125410mg·kg-1),每组5只.灌胃染毒,每天1次,连续12d.染毒结束后处死大鼠,称睾丸湿重、检测睾丸组织病理学及睾丸组织脂质过氧化状况.结果表明,各染毒组大鼠的睾丸均呈现毒性效应,表现为睾丸湿重降低,睾丸组织出现明显的病理学改变,丙二醛(MDA)水平升高、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性降低,这些毒性效应多数在联合染毒组表现更为明显.析因分析结果表明TCDD与Aroclor1254对大鼠睾丸的联合毒性效应为相加作用.以上结果提示TCDD与Aroclor1254单独和联合染毒均具有睾丸毒性,且二者的联合效应为相加作用,在对二噁英和PCBs进行环境风险评价时应考虑这种联合作用.

The Alone and Combined Toxic Effects of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin and Aroclor 1254 on Testes of Rats

To study the alone and combined toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD)and polychlorinated biphenyls(PCBs)on testes of rats,twenty SD rats were subjected to 2×2 factorial experimental design and assigned randomly into four groups of five rats each group,including control group,PCBs exposure group,TCDD exposure group,and the combined exposure group.Rats were administered intragastrically vehicle(olive oil),Aroclor 1254(Aroclor 1254 10mg·kg-1),TCDD(TCDD 10μg·kg-1)or the combination(TCDD 10μg·kg-1+Aroclor 1254 10mg·kg-1)once a day for consecutive 12 days.After sacrificed rats,testis weight,testicular histopathology,and testicular lipid peroxidation were determined.After exposure,all rats of treatment groups showed significant testicular toxicity,as characterized by decrease in the testis wet weight,testis histopathological changes,elevation in level of malondialdehyde and inhibition in activities of superoxide dismutase and glutathione peroxidase.Most of these effects were more remarkable in the combined exposure group.The results of ANOVA of the factorial design showed that the combined effect of TCDD and Aroclor 1254 on testes of rats may be additive.This study demonstrates that TCDD or Aroclor 1254 alone and combined exposure can induce testicular toxicity of rats,and the combined effect may be additive.Therefore,the potential combined effect of these pollutants should be considered in the process of environment risk assessment.