动脉粥样硬化对大鼠心肌缺血/再灌注损伤及缺血预处理保护作用的影响(英文)

Effects of hyperlipoidemic atherosclerosis on myocardial ischemia

目的探讨心肌缺血/再灌注(I/R)损伤及缺血预处理(IP)的保护作用是否受动脉粥样硬化的影响。方法48只健康Wistar大鼠随机分为2大组:正常大鼠组(NC rats)及动脉粥样硬化大鼠组(AS rats)。正常大鼠饲以标准实验室饲料,动脉粥样硬化大鼠连续3 d腹腔注射维生素D3后给以致动脉粥样硬化饲料。每大组动物又随机分为2小组:缺血/再灌注损伤组(I/R group)及缺血预处理组(IP group),NC-I/R和AS-I/R组大鼠给予45 min左室前壁缺血及180 min再灌注;NC-IP和AS-IP组大鼠在2次5 min缺血10 min再灌后给予45 min缺血及180 min再灌。检测指标为:心功能、心梗面积、心肌MPO活性、心肌MDA含量、心肌NO含量及iNOS活性。结果I/R使两组大鼠心肌均受到严重损伤,但AS大鼠损伤更重。IP可以明显减轻两组大鼠心肌I/R损伤,且两组大鼠IP的保护作用相似。结论动脉粥样硬化心脏更易受到I/R损伤,但是IP对动脉粥样硬化心脏仍然具有保护作用,且该作用和IP对正常大鼠的保护作用相似。

Objective To study whether the myocardial ischemla/repedusion injury and the protective role of ischemic preconditioning （IP） are affected by athemsclerosis. Methods Forty-eight healthy Wistar rats were randomly divided into 2 groups： normal control rats （NC rats） and athemsclemtic rats （AS rats）. NC rats were fed with standard laboratory chow, while AS rats were celiac injected for 3 days with vitamine D3 and then fed with an atherogenie diet. Each group was further randomly divided into 2 subgroups： ischemia/reperfusion （I/R） group and ischemic preconditioning （IP） group. NC-I/R and AS-I/R groups were subjected to 45 rain regional ischemia followed by 180 rain repedusion; while NC-IP and AS-IP groups were subjected to two cycles of preconditioning, comprising 5 rain regional ischem/a plus 10 rain reperfusion, prior to 45 rain ischernia followed by 180 rain reperfusion. Cardiac function,infarct size, myocardial MPO activity, MDA content, NO level and iNOS activity were measured. Results I/R caused pronounced myocardial injuries in both groups with, however,AS rats being more severely impaired than did NC rats. IP could significantly relieve the l/R-induced injuries to approximately the same extent in both NC rats and AS rats. Condus/on Atherosclerotic heart is more susceptible to I/R injury. However, the protective role of IP is still existed in the atherosclerotic heart to the same extent as in the normal heart.