热电厂锅炉灰粉尘对大鼠肺组织的早期毒效应

Early Toxic Effects of the Ash Dust from Boiler at a Power Station on the Lung Tissue of Rats

[目的 ]探讨某热电厂锅炉灰粉对染尘早期大鼠肺组织的毒性作用及其机制。 [方法 ]分别对石英组、灰粉尘组及对照组Wistar大鼠一次性气管内注入浓度为 5 0mg/ml的石英尘、锅炉灰粉悬浮液及生理盐水各 1ml ,染尘后 10d ,用 2 ,4 二硝基苯肼比色法、Folin 酚试剂法和钼蓝法测定支气管肺泡灌洗液 (BALF)中乳酸脱氢酶活性及总蛋白和磷酯含量 ,免疫组织化学染色法直接检测肺组织中的肿瘤坏死因子 α(TNF α)和转化生长因子 α(TGF α)的表达。 [结果 ]与生理盐水组相比 ,石英组和锅炉灰粉组大鼠BALF乳酸脱氢酶活性增高和总蛋白明显增加 (P <0 0 1) ,且石英组大于锅炉灰粉组 (P <0 0 1) ;锅炉灰粉组磷脂含量未见增高 (P >0 0 5 ) ,且明显低于石英组。生理盐水组未见TNF α表达 ,石英组和锅炉灰粉组均引起TNF α阳性表达 [(4 1 2 4± 3 2 6) %、(16 97± 1 85 ) % ] (P <0 0 1)。生理盐水组和锅炉灰粉组偶见肺泡上皮细胞表达TGF α[(2 19± 0 2 2 ) % ,(2 75± 0 2 7) % ] ,而石英组TGF α呈表达增多 (79 5 7± 5 0 9) % (P <0 0 1)。 [结论 ]染尘大鼠早期 ,锅炉灰粉能够引起大鼠肺组织损害 ,但毒性明显弱于石英尘。

To explore the toxicity of boiler ash dust at a thermal power station to rat lung tissues and its mechanisms . Wistar rats were exposed to quartz and the boiler ash dust by a single intratracheal instillation,and the activity of lactate dehydrogenase,total protein and phospholipid contents were determined in the bronchoalveolar lavage fluid(BALF);TNF α and TGF α in lung tissues were immunohistochemically determined. In comparison with the group inoculated with physiological saline alone,the activity of lactate dehydrogenase and total protein were significantly elevated in the group exposed to boiler ash dust ( P <0 01),but less elevated than in the group exposed to quartz ( P <0 01). The phospholipid content did not show any change ( P >0 05). The lung tissue cells exposed to quartz and boiler ash dusts had highly significant increase in TNF α immunostaining [(41 24±3 26)%,(16 97±1 85)%],control animals exhibited no expression of TNF α. The pulmonary epithelia in the control group and the boiler ash dust group showed a few TGF α immunostaining,however,a significant increase of the TGF α expression was observed in the lung tissue cells of rats exposed to quartz [(79 57±5 09)%] ( P <0 01). [Conclusion] In the early stage,the boiler ash dust could induce lung tissues injury,but the toxicity of the boiler ash dust was significantly lower than that of quartz.