大气细颗粒物有机成分在体染毒对大鼠胸主动脉血管反应的影响及其与NO/NOS的关系

目的探究大气细颗粒物PM2.5有机成分在体染毒对大鼠胸主动脉血管反应性的影响及其与血管内皮细胞NO/NOS系统的关系。方法 Wistar大鼠随机分为两组:①染毒组:PM2.5染毒溶液1 ml.kg-1.d-1,iv;②对照组:生理盐水1 ml.kg-1.d-1,iv。染毒10 d后,击晕大鼠,主动脉采血,用于检测血清一氧化氮(NO)和内皮型一氧化氮合酶(eNOS)含量、诱导型一氧化氮合酶(iNOS)活性。分离主动脉,用于离体主动脉实验和免疫组织化学染色分析,观察主动脉血管反应性和内皮细胞eNOS和iNOS蛋白表达。结果 PM2.5有机成分在体染毒后,可增强大鼠离体胸主动脉对60 mmol·L-1 KCl及苯肾上腺素(PE,10-5 mol·L-1)的收缩效应,减弱其对乙酰胆碱(ACh,10-9～10-5 mol·L-1)的舒张效应,但主动脉对硝普钠(SNP,10-9～10-5 mol·L-1)的舒张效应则不受影响。PM2.5有机成分在体染毒后,大鼠血清NO含量及iNOS活性增加,但eNOS含量则无明显变化;主动脉血管内皮细胞iNOS表达增加,eNOS表达减少。结论 PM2.5有机成分可影响大鼠胸主动脉环血管反应性,NO/NOS系统功能紊乱可能是其机制之一。

Effects on the isolated thoracic aorta vasomotion and NO/NOS system of PM2.5 organic components on rat by vein injected in vivo

Aim To observe the effects on vascular reactivity of isolated rat thoracic aortas rings and NOS/NO system of PM2.5 organic components on rat by vein injected in vivo.Methods Wistar rats were divided into two groups randomly:(1)organic group(PM2.5 organic extracts,1 ml·kg-1·d-1,iv);(2)control group(0.9% sodium chloride,1 ml·kg-1·d-1,iv).Rats were stunned and collected blood sample after treated 10 days.The concentration of NO,eNOS,and iNOS in plasma were detected respectively.The thoracic aortas were isolated to observe the aortas reactivity in vitro and protein expression of eNOS and iNOS by immunohistochemistry analysis.Results The contractions to KCl(60 mmol·L-1) and PE(10-5 mol·L-1) were increased,while the relaxation to Ach(10-9~10-5 mol·L-1) was attenuated,but SNP(10-9~10-5 mol·L-1) induced vasorelaxation was not changed in PM2.5 organic group.Levels of NO and iNOS activity in plasma were increased but the concentration of eNOS was not changed.The protein expression of iNOS increased but eNOS decreased in aorta endothelia after PM2.5 organic components treated.Conclusion The effect of PM2.5 organic components on rat aorta may be related to dysfunction of NOS/NO system.