地塞米松预处理对大鼠心肌HSP72的表达和I/R心肌梗塞面积的影响

目的 探讨地塞米松预处理对SD大鼠心肌热休克蛋白72(HSP72)的表达和缺血-再灌注(I/R)心肌梗塞面积的影响.方法 SD大鼠随机分成地塞米松、安慰剂组,分别给予地塞米松和生理盐水预处理.24小时后构建Langendorff离体心脏I/R动物模型,缺血30分钟后再灌注60分钟,Western blot法和免疫组化法观察心肌HSP72表达变化;TTC染色,影像法测定心肌梗塞面积.结果 地塞米松预处理诱导大鼠心肌HSP72的表达较安慰剂组显著增加(P＜0.05);经地塞米松预处理后可缩小心肌梗塞面积(P＜0.01).结论 地塞米松作为新型HSP72诱导剂,上调HSP72表达,可有效地缩小大鼠I/R心肌的梗塞面积.

Effect of dexamethasone pretreatment on HSP72 Expression and Sizes of Myocardial Infarction Induced by Ischemia/reperfusion in rats

Objective To explore the expression of myocardium heat shock protein 72(HSP72) and the myocardial infarct sizes on inchemia/reperfusion by dexamethasone (DEX) pretreatment in rats. Methods 46 Sprague-Dawley rats were divided randomly into the DEX and vehichle (VEH) group, the rats had been pretreated with DEX or sodium chloride for 24 hours before their hearts were separated for Langendorff perfusion and for ischemia/reperfusion. The hearts were perfused with TTC after 60-minute reperfusion following 30-minute ischemia. The myocardial infarct size was measured through Adobe Photoshop. HSP72 was examined by western blotting and immunohistochemistry. Results Compared with vehicle group, the expressions of HSP72 was significantly increased (P<0.05); the infarct sizes were reduced significantly (P<0.01). Conclusion As a novel inducer of HSP72, DEX induces increased of HSP72, which functions to significantly decrease the infarction sizes during I/R.