不同地域的典型温石棉对wistar大鼠的氧化损伤作用

Representative chrysotile asbestos in different regions induced oxidative damage in wistar rats

目的探讨4种不同地域的典型温石棉对wistar大鼠肺部氧化损伤作用及其作用强度比较。方法从矿区采集甘肃阿克塞、四川新康、陕西陕南和青海茫崖4种温石棉,加工成粒径小于10μm的颗粒物。X光荧光衍射分析样品主要化学成分,激光粒度分析仪测定粒径。选60只初断乳清洁级wistar大鼠,随机分为5组(陕西陕南、青海茫崖、四川新康、甘肃阿克塞温石棉染毒组和阴性对照组),染毒组采用非暴露式气管内滴注浓度为2.0 mg/ml温石棉悬液0.5 ml,染毒频率1次/月;阴性对照组采用相同方法滴注灭菌生理盐水0.5 ml。上述5组大鼠分别于实验1、3和6个月后分批处死大鼠4只,称其体质量、肺质量,肺组织苏木素-伊红(HE)染色观察病理形态改变;测定肺组织匀浆和血清中活性氧簇(ROS)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活力。结果四川新康和青海茫崖染毒组大鼠体质量增长缓慢,肺质量增加;HE染色显示,不同地域温石棉染毒组都有不同程度的炎性细胞聚集、肺泡结构破坏和纤维化,损伤随染毒时间延长加重;与相同染毒时间的阴性对照组比较,青海茫崖和四川新康染毒组大鼠肺组织和血清中ROS、MDA的含量分别于染毒1和3个月始增加(P<0.05),SOD活力先升高后降低(P<0.05),随染毒时间的延长,肺组织和血清中MDA含量增加(P<0.05),SOD活力呈下降趋势(P<0.05)。结论四川新康和青海茫崖温石棉可致大鼠体内产生过量ROS,导致脂质过氧化作用,抗氧化酶SOD耗竭或失代偿,清除自由基的能力下降,造成大鼠的肺氧化应激损伤,提示不同地域温石棉氧化损伤作用可能存在差异。

Objective To investigate the effect of representative chrysotile asbestos in 4 different regions on pulmonary oxidative damage in Wistar rats,and to compare the oxidative damage of those. Methods Representative chrysotile were collected from four mining area,and processed into particles with a particle size less than 10 μm. The main chemical components of samples were analyzed by X ray diffraction analyzer,the particle size was measured by laser particle size analyzer. Wistar rats were administered by intratracheal instillation for 2. 0 mg/ml of 4 different chrysotiles（ Shanxi,Qinghai Mangya,Sichuan Xinkang,Gansu Akesai） dissolved in saline,and the negative control group was treated with physiological saline in the same way,repeatedly once a month for 6 month with 0. 5 ml. Four rats were sacrificed then detecting rat weight,lung weight,reactive oxygen species（ ROS） content,malondialdehyde（ MDA） content,superoxide dismutase（ SOD） activity in serum and lung tissue homogenate of rats with 1,3 and 6 months respectively. Result In Sichuan Xikang and Qinghai Mangya group,in chrysotile exposed-group,body weight grow slowly and the lung weight were higher than negative control group（ P〈0. 05）. Inflammatory cell aggregation,destruction of alveolar structureand fibrosis were observed in HE staining. The different content of ROS,MDA between Sichuan Xikang,Qinghai Mangya and negative control group is significantly,meanwhile the SOD activities were increased firstly and then decreased in both lung tissue and serum. With the increasing of exposure time,the content of MDA increased（ P〈0. 05） and the activity of SOD showed a decreasing trend in lung tissue and serum（ P〈0. 05）. Conclusion Sichuan Kang and Gansu mangnai chrysotile can produce excessive ROS,Resulting in lipid peroxidation and SOD activity decreased in vivo. This process may break down the balance between oxidative and antioxidant,finally lead to lung oxidative damage in rats. The result suggest that there may be differences in oxidative damage between representative chrysotile asbestos in different regions.