光气染毒小鼠急性肺损伤的浓时积与效应关系研究

Study on the Ct-effect relation of acute lung injury induced by phosgene in mice

目的通过比较光气染毒浓时积(Ct)的两个参数(浓度C与时间t)对染毒小鼠急性肺损伤程度的影响,探讨光气导致急性肺损伤的机制。方法以不同浓时积和固定浓时积不同浓度与时间进行光气染毒,测定肺脏湿干比、丙二醛(MDA)含量和髓过氧化物酶活力以及血清中MDA含量。结果随染毒浓时积增加,小鼠中毒死亡率增加(P<0.001);浓时积固定为12ml.min时,染毒浓度增加,小鼠中毒死亡率增加(P<0.01),肺湿干比增加(P<0.001),肺脏髓过氧化物酶活力和MDA浓度升高(P<0.05)。结论光气染毒随浓时积增加,动物中毒死亡率升高,但在浓时积相同的条件下,暴露毒剂的浓度与暴露时间对急性中毒的影响不同;暴露毒剂的浓度高低对中毒程度的影响远大于暴露时间的影响,短时间高浓度的光气吸入会比低浓度长时间的光气吸入造成更为严重的肺部损伤。

Objective By comparing with the effects of two parameters （exposure concentration and exposure time） of concentration × time（Ct） product on degree of acute lung injury of mice induced by phosgene, to study the mechanism of acute lung injury induced by phosgene. Methods The mice were respectively exposed to phosgene under the different Ct product and the same Ct product but different exposure concentrations and exposure times. The wet/dry radio of lung, the enzyme activity of MPO in lung and the content of malondialdehyde （MDA） in lung and serum were detected. Results With Ct product increasing, death rate of mice increased significantly （P〈 0. 001 ）. Under the same Ct product of 12 ml.min, death rate increased significantly （P 〈 0.01 ） by the exposure concentration. The wet/dry radio of lung increased significantly （P〈0. 001 ）. The enzyme activity of MPO and the content of MDA in lung were both higher than that of the control （P 〈 0.05）. Conclusions With Ct products increasing, death rate of mice exposed to phosgene increased. However, under the same Ct product, exposure concentration and exposure time had different effects on degree of lung injury. It was found that exposure concentration affected degree of lung injury much more than exposure time. Exposure to high concentration of phosgene for short time would induce more severe lung injury than that to low concentration of phosgene for long time.