PM2．5急性暴露对大鼠凝血功能的影响及其机制

目的探讨PM2．5暴露对大鼠凝血功能的影响及机制。方法24只雌性SD大鼠随机分为4组：对照组、PM2.53．75mg／kg组、PM257．5mg／kg组、PM2s15mg／kg组。将大鼠暴露于不同剂量PM2．5，24h后处死大鼠，取大鼠血浆检测凝血酶原时间（PT）、活化的部分凝血活酶时间（APTT）、纤维蛋白原（FIB），取BALF显微镜下细胞计数及分类，大鼠肺脏石蜡切片HE染色观察病理改变，酶联免疫吸附试验法检测BALF中IL-6、肿瘤坏死因子α（TNFd）含量、肺组织丙二醛（MDA）含量及血清血管性血友病因子（vWF）含量，蛋白免疫电泳法（Westernblot）检测血管紧张素Ⅱ的1型受体（ATl）蛋白表达。结果PM2.57．5mg／kg组、PM2.5 15mg／kg组PT、APTT值较对照组及PM2.53．75mg／kg组缩短（P〈0．05），各组血浆FIB值均无统计学差异（P〉0．05）。PM2.5各剂量组BALF中细胞总数及中性粒细胞比例均明显高于对照组（P〈0．05），且随着PM2.5剂量增加而呈剂量依赖性升高。PM2.57．5mg／kg组和PMzs15mg／kg组BALF中II-6、TNF-α含量、肺组织MDA含量、血清vwF含量及肺组织ATl受体蛋白表达明显高于对照组及PM2.53．75mg／kg组（P〈0．05）。结论PM2.5暴露可导致PT、APTT缩短，诱发血液高凝，其机制可能与炎症反应及血管内皮损伤相关。

Effects and mechanisms of short-term exposure to PM2.5 on blood coagulation function in rats

Objective To investigate the effect of PM2 s on coagulation in rats,and further elucidate its mechanism on inflammation and endothelial injury. Methods A total of 24 rats were divided into four groups. We developed a rat model in which the animals were exposed to PM2.5 in a 24h dose-response study （3.75 mg/kg,7.5 mg/kg,and 15 mg/kg）. Prothrombintime （PT）,activated partial thromboplastin time （APTT）,and fibringen （FIB） in plasma were detected. The total and differential cell counts in the BALF were observed. The contents of malondialdebyde （MDA）, interleukin-6 （IL-6）, tumor necrosis factor-a （TNF-6）, and von Willebrand factor （vWF） were detected by ELISA. Western blot was performed to detect the protein level of angiotensin H type 1 receptor （AT1）. Results PT and APTT in 7.5 mg/kg group and 15 mg/kg group were obviously shortened than those in control group and 3.75 mg/kg group （ P 〈 0.05）. The total cell number and the percentage of neutrophils in BALF in 3.75 mg/kg group,7.5 mg/kg group,and 15 mg/kg group were obviously higher than those in control group. The contents of MDA, IL-6, TNF u,and vWF in 7.5 mg/kg group and 15 mg/kg group were obviously higher than those in control group and 3.75 mg/kg group. And the protein level of AT1 in lung of 7.5 mg/kg group and 15 mg/kg group was obviously higher than those in control group and 3.75 mg/kg group. Conclusions PT and APTT can be shortened by short-term exposure to PM2.5 , and that would lead to hypercoagulable state,which is related to inflammatory changes and endothelial damage.