大气PM_(2.5)对大鼠心血管系统的急性毒性作用

Acute effects of fine particle on cardiovascular system of rats

目的观察大气PM2.5对机体心血管系统的影响,比较PM2.5对不同生理、病理状态下大鼠心血管系统毒性的差异。方法在上海市非工业区采集大气PM2.5,选取SH和WKY大鼠各24只,采用气管滴注染毒方法给大鼠肺灌注不同剂量PM2.5,观察PM2.5对不同机体心血管系统的急性毒作用,测量染毒后动物血清心肌酶学(乳酸脱氢酶LDH和肌酸激酶同工酶CK-MB)及血压、心率、心电图。结果大鼠PM2.5染毒后,测定大鼠血清心肌酶发现,WKY和SH大鼠血清LDH和CK-MB随染毒剂量增加而增加,且与对照组相比有统计学差异;同时SH大鼠各实验组心肌酶含量除CK-MB的低剂量组外均高于WKY大鼠的相应组含量,表明PM2.5对SHR的心血管毒性作用可能大于对WKY大鼠的作用。此外,两种大鼠肺灌注PM2.5后血压和心率与对照组相比有明显改变,且染毒后大鼠心电图ST段与T波发生改变。结论结果提示暴露于PM2.5对机体心血管系统有一定的损伤作用,心肌出现缺血缺氧反应。

Objective To observe the effects of fine particle on cardiovascular system of rats and compare fine particle toxicity on rats suffered from different condition and find the possible toxicological mechanism of fine particle. Methods Fine particle were collected using Thermo Anderson G-2.5 apparatus in Shanghai. Twenty-four spontaneous hypertension rats （SHR） and age-matched twenty-four WKY rats were used as subjects in order to study the effects of fine particle on cardiovascular system. The animals were divided into four groups and submitted to the instillation of saline and different dose fine particle. Twenty-four hours after instillation, direct measurements of arterial blood pressure and observation of electrocardiogram were obtained by catheterization of the carotid, and collected blood serum for measuring enzymes. Results With the increase of the concentration of fine particle, blood pressures and heart rates of WKY rats and SHR significantly increased. In every treatment groups, the blood pressures and heart rates were higher than those of control groups. At the same time, not only in WKY rats but also in SHR, the levels of lactate dehydrogenase （LDH） and MB isoenzyme of creatine kinase（CK-MB） were increased with the concentration of fine particle, and the levels of two kinds of enzymes in exposure groups were more higher than those of control groups. Furthermore, the levels of two kinds of enzymes of SHR groups at the doses of different treatment were more than those of WKY rats. Conclusion The results showed that fine particle could be cardiovascular system toxicity for WKY rats and SHR, and SHR seemed more susceptible to fine particle than those of WKY rats.