亚慢性2,3,7,8四氯二苯并二噁英暴露对大鼠肝脏的毒性

Liver Toxicity of Subchronic 2,3,7,8-tetrachlorodibenzo-p-dioxin Exposure in Rats

目的:了解亚慢性2,3,7,8四氯二苯并二噁英(TCDD)暴露对大鼠肝脏的毒性作用。方法:1月龄SD大鼠随机分为阴性对照组(予玉米油)和3个TCDD(2、10和50 ng.kg-1.d-1)实验组,每组30只,雌雄各半,连续暴露13周后测定血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)活性,观察肝脏病理组织学变化。结果:亚慢性TCDD暴露对大鼠体质量和主要脏器相对重量无明显影响;血清AST和ALT活性在实验组升高:雌鼠AST和ALT在10和50 ng.kg-1.d-1组高于对照组和2 ng.kg-1.d-1组(P<0.05);雄鼠AST在50 ng.kg-1.d-1组高于其它3组(P<0.05),ALT在各组间差异无统计学意义;病理观察发现实验组肝组织坏死,肝血窦瘀血和肝细胞空泡样变。结论:亚慢性TCDD暴露对大鼠肝脏具有毒性作用,且雌鼠比雄鼠的肝脏对TCDD的毒性更敏感。

Objective：To study the liver toxicity of subchronic 2,3,7,8-tetrachlorodibenzo-p-dioxin（TCDD）exposure in rats.Method：One hundred and twenty one-month-old rats were allocated randomly into control group（given corn oil）and three doses of TCDD（2,10 and 50 ng·kg-1·d-1）groups,30 rats in each group,in half respectively male and female.The exposure lasted for 13 weeks.Thirteen weeks later,the serum levels of alanine transaminase（ALT）and aspartate amino transferase（AST）were tested,the hepatic histopathology observation was also performed.Results： Subchronic TCDD exposure had no obvious effects on the body weight and the relative weight of main organs in rats.In females,AST and ALT in the 10 and 50 ng·kg-1·d-1 groups were higher than control and 2 ng·kg-1·d-1 groups（P0.05）.In males,the AST level in the 50 ng·kg-1·d-1 group was higher than other three groups（P0.05）,no significant differences were found in ALT among groups.The pathological changes were found in TCDD treated liver,such as necrosis,gore in hepatic sinusoid and vacuolization of hepatocytes.Conclusion： Subchronic TCDD exposure has toxic effects on rat liver,the female rats are more sensitive to TCDD liver toxicity than males.