大气PM2．5对自发性高血压大鼠血液指标的影响

The Effects of PM2.5 on Blood Parameters of SHRs

了解急性暴露于PM2.5，敏感个体可能再现的血液指标改变。方法：12-13周龄的雄性自发性高血压大（spontaneously hypertension rat,SHR）24只，随机分4组，实验组气管滴注颗粒物悬浮液1.6、8.0、40.0mg/kg体重，对照组气管滴注生理盐水，连续染毒3天，最后一次染毒后24小时，处死大鼠，采血样进行白细胞计数，测血浆纤维蛋白原含量和血浆粘度。染毒前和最后一次染毒后24小时测大鼠血压。结果：高剂量组大鼠外周血白细胞数明显上升至9.4±0.7（p〈0.05）。各染毒组血浆纤维蛋白原含量和血浆粘度与对照组相比则都显著升高，分别为7.612±1.330g/L（p〈0.05）、7.721±1.435g/L（p〈0.01）、16.329±2.375g/L（p〈0.01）和1.40±0.40mPas（p〈0.05）、1.41±0.04mPas（p〈0.05）、1.48±0.05mPas（p〈0.01）。血浆纤维蛋白原含量和血浆粘度与染毒剂量有剂量-反应关系，说明PM2.5颗粒物通过全身性炎性症导致血浆纤维蛋白原含量上升，而血浆纤维蛋白原又是致血浆粘度升高的重要因素，两者都与心血管疾病密切相关。

Twenty-four male spontaneously hypertension rats （SHRs） with the age of 1213 weeks were distributed to four groups randomly. By means of intra-tracheal instillation for consecutive 3 days, three exposure groups were exposed to PM2.5 with various concentrations of 1. 6,8.0, and 40. 0 mg/kg representing for low, middle and high dose respectively. Twenty-four hours late of the last time of instillation, all animals were sacrificed and blood samples were collected for WBC count and analysis for plasma fibrinogen levels and plasma viscosity. The mean level of peripheral WBC count in high-dose group was 9.4±0. 7 109/L（p〈0. 05） which have a statistic significance compared with the control. The average plasma fibrinogen levels and plasma viscosity of SHRs in every exposure group were significantly higher than that of the control. They were 7.612±1.330 g/L （p〈0. 05）, 7.721±1.435 g/L （p〈0. 01）, 16.329±2.375 g/L （p〈0. 01） for Plasma fibrinogen levels ranged from low, middle and high exposure group respectively and 1. 40±0. 04 mPas （p〈0. 05）, 1. 41±0. 04 mPas （p〈0. 05）, 1. 48±0. 05 mPas （p〈0. 01） for plasma viscosity of SHRs respectively. A significant dose-dependent relationship of PF and PV was observed. In conclusion, exposed to PM2.5 can induced increase of blood pressure and systemic inflammation with an increased level of plasma fibrinogen one of factors responsible for increase of plasma viscosity. Increase of both plasma fibrinogen and plasma viscosity is closely related with cardiovascular events.