中文摘要：

目的：探讨运动预适应（EP）对异丙肾上腺素（ISO）导致的大鼠急性心肌缺血损伤的早期保护作用。方法：健康雄性SD大鼠52只,随机分为对照组（C组）、运动预适应组（EP组）、异丙肾上腺素组（ISO组）、运动预适应＋异丙肾上腺素组（EP＋ISO组）。在EP模型的基础上,用大剂量ISO复制大鼠急性心肌缺血损伤模型,采用HE染色、HBFP染色和计算机图像分析技术显示大鼠心肌缺血缺氧的改变,用免疫化学发光法检测大鼠血清心肌肌钙蛋白Ⅰ（cTnl）的含量。结果：（1）与C组相比,EP组HE染色均匀,轮廓清晰,HBFP染色未见缺血缺氧改变;血清cTnl升高,但无统计学意义（P〉0.05）。（2）与C组相比,ISO组HE染色显示心肌细胞肿胀红染,细胞界限模糊,HBFP染色可见明显的缺血缺氧改变;血清cTnl升高显著（P〈0.05）。（3）与ISO组相比,EP＋ISO组心肌缺血缺氧改变较轻,缺血缺氧面积和平均光密度明显减少（P〈0.05）;血清cTnl明显降低（P〈0.05）,但仍显著高于C组（P〈0.05）。结论：EP诱导机体产生了缺血预适应的保护效应,能够减轻ISO导致的急性心肌缺血损伤的程度,对急性心肌缺血损伤具有一定的保护作用。

英文摘要：

Objective In this paper, early protective effect of exercise preconditioning （EP） on the isoproterenol （ISO）-induced acute myocardial ischemic injury in rats was investigated. Methods Fifty two healthy male SD rats were randomly divided into control group （C）, EP group, ISO group and EP＋ISO group. After establishing of EP animal model, the rats were injected with high dose of ISO to induce acute myocardial ischemia. Then the changes in myocardial hypoxic-ischemic area （HE staining and HBFP staining） was computed, and serum cardiac troponin Ⅰ（cTnⅠ） level was detected by chemiluminescent irnmunoassay. Results （1） As compared with the group C, no ischemic-hypoxic morphologic change was observed in cardiac myocytes （HE staining） and the cTnⅠ level in serum increased without statistical significance in group EP （P 〉0.05）. （2） As compared with the group C, significant ischemic-hypoxic morphologic changes appeared in cardiac myocytes in group ISO （HE and HBFP staining）, and the cTnⅠ level in serum increased significantly in group ISO as well （P〈0.05）. （3） As compared with the group ISO, the degree of ischemia in cardiac myocytes（HE and HBFP staining） altered slightly in group EP＋ISO; the ischemic-hypoxic area and value of mean optical density decreased significantly （P 〈0.05）, and the cTnⅠ level in serum increased significantly （P〈0.05）, whereas was still higher than that in group C. Conclusion EP mitigates ISO-induced acute myocardial ischemic injury significantly.