沙尘暴PM_(2.5)颗粒对大鼠心电的影响

The effects of PM_(2.5) particles in sandstorm on ECG in rats

目的观察不同剂量的沙尘暴PM2.5颗粒暴露对大鼠心电图及心脏质量指数的影响。方法 60只15周龄的Wistar大鼠随机分成4组:空白组、低剂量组、中剂量组、高剂量组,每组15只,配制不同浓度的PM2.5颗粒混悬液,后3组分别给予1.5、6.0、24.0 mg/kg的PM2.5颗粒混悬液进行气管滴注,空白组滴注等剂量的生理盐水,共滴注7天后检查心电图,观察并记录心率、节律、P波时限、PR间期、QRS波时限、ST段、T波、QT间期等。结果 (1)低、中、高剂量组的心率较空白组明显减慢且呈剂量依赖性(P<0.05);QRS波时限、RR间期明显延长(P<0.05);P波时限、PR间期、QT间期均无明显差异(P>0.05)。(2)低、中、高剂量组较空白组相比各组的P波、S波振幅增加,T波振幅降低,ST段抬高且呈剂量依赖性(P<0.05);Q波、R波振幅无明显差异(P>0.05)。(3)低、中、高剂量各组出现异常心电图的频率较空白组明显增加(P<0.05)。(4)中、高剂量组的心脏质量指数较空白组明显增加(P<0.05),低剂量组的心脏指数与空白组相比较变化不明显(P>0.05)。结论暴露于沙尘暴PM2.5可导致大鼠心电改变、出现异常心电图的频率增高、心脏质量指数增加。

Objective To observe the effects of different doses of PM2.5 particles exposure on the electrocardiogram and heart mass index of rats. Methods Sixty Wistar rats aged 15 weeks were randomly divided into 4 groups with 15 rats in each group, which were respectively labeled as blank control group, low-dose group, medium-dose group and high-dose group. From different concentrations of PM2.5 particles suspension liquid, the later three groups were given 1.5, 6.0,24.0 mg/kg of PM2.5 particles suspension liquid tracheal drip, respectively, and the blank group was intratracheally instilled with an equal dose of normal saline. The electro-cardiogram was examined 7 days after infusion, observation and records the heart rate, rhythm, P wave, PR interval period, QRS wave, ST segment and T wave, QT interphase, etc. Results(1)Compared with the blank group, the heart rate of the low, medium and high dose groups slowed down significantly and was dose-dependent(P<0.05);the QRS wave width, RR interval was significantly prolonged(P<0.05), and P width, PR interval and QT interval were not significantly different(P>0.05).(2)Compared with the blank group, the amplitude of P wave, S wave in low, medium and high doses increased, the amplitude of T wave doses reduced and the ST segment was elevated in a dose-dependent manner(P<0.05).There was no significant difference in amplitude between Q wave and R wave(P>0.05).(3)The frequency of abnormal ECG in the low, medium and high dose groups was significantly increased compared with the blank group (P<0.05).(4)The heart mass index of the middle and high dose groups was significantly increased compared with the blank control group(P <0.05),while the heart mass index of the low dose group was not significantly changed compared with the blank group(P>0.05). Conclusion Exposure to PM2.5 of sandstorm can caused changes in ECG,increased frequency of abnormal ECG,and increased cardiac mass index in rats.[Chinese Journal of Cardiac Pacing and Electrophysiology,2021,35(5):458-462]