中文摘要：

目的：探讨运动预适应（EP）对心肌BNP表达变化的影响以及在运动预适应保护效应期间BNP是否发挥了保护效应。方法：SD大鼠分为对照组（C组）、大强度运动组（HE组）、早期运动预适应组（EEP组）、晚期运动预适应组（LEP组）、早期运动预适应＋大强度运动组（EEP＋HE组）、晚期运动预适应＋大强度运动组（LEP＋HE组）。在EP动物模型基础上,通过大强度运动致大鼠运动性心肌损伤。用免疫化学发光法检测血浆cTnI含量,HE染色、HBFP染色法和变色酸2R-亮绿染色法检测心肌形态及缺血缺氧改变。分别通过免疫组织化学法和酶联免疫吸附法检测心肌组织和血浆中的BNP表达变化。结果：与C组相比,HE组cTnI和缺血缺氧水平显著升高,而EEP组和LEP组无显著差异;HE组、EEP组和LEP组心肌组织BNP均呈显著性升高,而血浆BNP仅HE组和EEP组有显著性升高,LEP组却无明显差异。与HE组相比,EEP＋HE组和LEP＋HE组cTnI和缺血缺氧水平明显下降,心肌组织BNP均呈显著性升高,而血浆BNP仅LEP＋HE组有显著升高,EEP＋HE组无显著性差异。结论：EP可有效促进心肌分泌BNP,且BNP参与了EP对运动性心肌损伤的保护效应。

英文摘要：

Objective：To view the change of B-type natriuretic peptide（BNP）expression during exercise preconditioning and determine whether BNP participated incardioprotective effect of exercise preconditioning.Methods：SD rats were divided into control group（C）,HE group,EEP group,LEP group,EEP＋HE group,and LEP＋HE group.After establishing of EP animal model,high-intensity exercise on treadmill for inducing myocardial injury.Then the lever of cTnI was detected by chemiluminescent immunoassay.HE staining was used to observe the changes in ventricular structure.Hematoxylin-basic-fuchsin-picric acid（HBFP）staining and Chromotrope 2R-brilliant green（C-2R）staining were evaluated the degree of myocardial ischemia/hypoxia.The change of BNP in myocardium and plasma were detected by immunohistoChemistry and enzyme inked immunosorbent assay respectively.Results：As compared with the group C,there was no significant difference in the level of cTnI and the degree of myocardial ischemia/hypoxia,but it has a significant increase in group HE.Compared with the group C,the expression of BNP in myocardium was increased significantly in group HE,group EEP and group LEP,but the level of BNP in plasma significantly increase only in group HE and group EEP,group LEP has no significant difference.As compared with group HE,there was a significant decrease in the level of cTnI and the degree of myocardial ischemia/hypoxia in group EEP＋HE and group LEP＋HE.Compared with group HE,the expression of BNP in myocardium was increased significantly in group EEP＋HE and group LEP＋HE,but the level of BNP in plasma significantly increase only in group LEP＋HE,group EEP＋HE has no significant difference.Conclusion：exercise preconditioning can induce myocardium to produce BNP,and BNP participated in cardioprotective effect of exercise preconditioning.