大气PM_(2．5)对自发性高血压大鼠心脏的急性毒作用

Study on Acute Toxic Effects of PM_(2.5) on Heart in Spontaneous Hypertension Rats

[目的]了解敏感个体急性暴露PM2.5可能出现的心脏损伤。[方法]12-13周龄的雄性自发性高血压 (spontaneous hypertension,SH)大鼠24只,随机分4组,其中3个实验组分别气管滴注不同浓度的PM2．5颗粒物悬浮液1．6、 8．0、40．0 mg/kg体重,对照组气管滴注生理盐水,连续染毒3 d。[结果]各组大鼠的心脏/体重比值相差不大。高浓度组与对照组相比,心脏生长转化园子β1(transforming growth factor-β1,TGF-β1)的mRNA表达明显升高(P<0．01)。心脏病理学改变随着染毒浓度的增加越加严重。[结论] PM2.5对SH大鼠心脏有一定的急性毒作用,并可引起心脏重构。

[ Objective ] To research the possible heart lesion of sensitive individuals exposed to PM2.5 in short term. [ Methods ] Twenty-four male spontaneous hypertension rats（ SHRs ）with the age of 12-13 weeks were decided into four groups randomly. By means of intra-tracheal instillation for consecutive 3 days, three exposure groups were exposed to PM2.5 with various concentrations at a dose of 1.6, 8.0 or 40.0 mg/kg representing for low, middle and high doses respectively. A control group was instillated saline. [ Results ] There was no obvious difference in ratio of heart weight/body weight between the control group and treated groups （ P 〉 0.05 ）. Compared to the control group, there was over-expression in mRNA of TGF-β1 （ transforming growth factor-β1）in high-dose group. The result of pathologic change showed that the cardiac lesion became more severe with increase of the dose of PM2.5. [ Conclusion ] PM25 can cause acute toxic effects on SHR＇ s.heart and myocardial remodeling.