高温应激对大鼠心肌血管紧张素Ⅱ的影响及其与心肌p22phox表达的关系  

Effect of heat stress on angiotensinⅡ expression in rat myocardium and its relationship to p22phox

作　　者：侯小玲[1] 赵连友[1] 薛玉生[1] 艾永飞[1] 景晓娟[1] 牛晓琳[1] 赵晓燕[1] 尚福军[1] 

机构地区：[1]第四军医大学唐都医院心血管内科,陕西西安710038

出　　处：《心脏杂志》2009年第3期304-308,共5页Chinese Heart Journal

基　　金：军队"十一五"重要军事医学基础研究项目资助(062074)

摘　　要：目的观察高温应激对大鼠心肌血管紧张素Ⅱ(AngⅡ)的影响,探讨心肌AngⅡ与心肌p22phox表达的关系。方法将24只成年雄性SD大鼠,随机分为:对照组、高温组、高温高湿组,每组8只。喂养4周后,颈动脉插管测定平均动脉压。用放射免疫法测定血浆和心肌AngⅡ浓度。用比色法测定心肌活性氧(ROS)水平。应用逆转录聚合酶链式反应(RT-PCR)和免疫组化法检测心肌p22phox mRNA及蛋白的表达水平。结果高温组和高温高湿组大鼠平均动脉压、AngⅡ浓度、ROS水平、p22phox mRNA及蛋白的表达水平与对照组比较,均有显著升高(P<0.01);高温高湿组与高温组比较,无显著性差异。结论高温应激使大鼠血压升高,这可能与AngⅡ水平上调有关。AngⅡ介导ROS生成增加,其机制可能是高温应激引起p22phox超常表达所致,提示高温应激可引起心脏损害。AIM To study the effect of heat stress on the expression of angiotensin Ⅱ （Ang Ⅱ ） in the myocardium and to investigate the interrelation between Ang Ⅱ and p22phox in the myocardium. METHODS Twenty-four SD rats were divided randomly into three groups： the control group, the high temperature and high humidity stress group, and the heat stress group. All examinations were performed four weeks later. Mean arterial blood pressure （MBP） was measured by carotid artery intubation and reactive oxygen species （ROS） was determined with spectrophotometer. The concentration of AngⅡ in the plasma and myocardium was detected respectively by radioimmunoassay and expression level of p22phox mRNA in myocardium was determined by reverse transcription polymerase chain reaction （RT-PCR）. P22phox protein was detected by immunohistochemistry and semi-quantitative analysis in different groups. RESULTS Four weeks after heat stress, MBP in the heat stress group and the high temperature and high humidity stress group increased significantly （ P 〈 0.01 ）, but no significant difference was observed in LVW/BW index （P 〉 0.05 ） compared with those in the control group. The concentration of Ang lI in the plasma and the myocardium and the ROS level of myocardium significantly increased （both P 〈 0. 01 ） , and the expression of p22phox mRNA and protein levels of myocardium also increased signifi- cantly （P 〈0. 01 ） in the heat stress group and the high temperature and high humidity stress group.CONCLUSION The concentration of Ang Ⅱ in the plasma and myocardium and p22phox in the myo- cardium increase in heat stress conditions. Heat stress may be associated with over production of ROS, which is induced by increased expression of Ang Ⅱ.

关 键 词：高温应激 血管紧张素Ⅱ 活性氧 P22PHOX 

分 类 号：R972.5[医药卫生—药品]