血管紧张素转化酶抑制剂和抗氧化剂对湿热应激性大鼠心肌AngⅡ和p22phox表达的影响

目的:观察血管紧张素转化酶抑制剂(ACEI)卡托普利(Captopril,CTP)和抗氧化剂（维生素C，VitC）对湿热应激(HHS)大鼠心肌组织中血管紧张素Ⅱ（AngⅡ)、活性氧簇（ROS）和p22phox表达的影响。方法: 将32只成年雄性SD大鼠随机分为:对照组、HHS组、CTP组(HHS+CTP)及VitC组(HHS+VitC)，每组8只。喂养4周后，颈动脉插管测定大鼠血压，计算大鼠左心室质量指数。用放射免疫法测定心肌组织中AngⅡ的浓度。用比色法测定心肌组织中ROS的水平。应用RT-PCR检测p22phox mRNA的表达。用免疫组化染色法检测大鼠心肌中p22phox的分布特征。结果: 平均动脉压、AngⅡ和ROS和p22phox的水平，HHS组与对照组比较，VitC组和CTP组与HHS组比较，均有非常显著性差异（P<0.01）；两个药物组之间比较无统计学意义。结论: HHS可增加大鼠心肌组织中AngⅡ表达，同时上调p22phox mRNA和其蛋白的表达，介导心肌细胞内ROS生成增加。用抗氧化剂和ACEI阻滞后，AngⅡ表达减少，p22phox mRNA和其蛋白的表达降低，心肌细胞内ROS生成减少，其机制可能与HHS导致AngⅡ诱导ROS产生有关。以上提示，HHS可引起心脏损害，抗氧化剂和ACEI对HHS性心脏损害具有拮抗作用。

Effect of angiotensin-converting enzyme inhibitors and antioxidants on heat stress-induced expression of rat p22phox

AIM:To study the effect of heat stress on the expression of reactive oxygen species(ROS),p22phox and angiotensin II(Ang II) in myocardium and to investigate the interrelation among ROS,p22phox and Ang II in myocardium.METHODS:Twenty-four Sprague Dawley rats were divided randomly into three groups:control group,high temperature and high humidity stress group and heat stress group.All examinations were performed 4 weeks later.Mean arterial blood pressure(MABP) was measured by carotid artery intubation and ROS...