Rat model of exercise-induced myocardial ischemia injury / 中国组织工程研究

ABSTRACT

BACKGROUND:No uniform standard for constructing the animal model of exercise-induced myocardial ischemia injury results in the incomparability among research results and impedes the development of sport medicine especial y in the cardiovascular field;thereby, it is imperative to reach an agreement in constructing criteria. OBJECTIVE:To explore the method of establishing the rat model of myocardial ischemia induced by running. METHODS:Total y 96 female Sprague-Dawley rats were randomly divided into rest control group, isoprenaline group and 10 exercise groups (1-and 3-time moderate-intensity exercise groups, 1-, 2-and 3-week moderate-intensity exercise groups, 1-and 3-time high-intensity exercise groups, 1-, 2-and 3-week high-intensity exercise groups). After exhaustive exercise, myocardium was col ected for morphological observation by hematoxylin-eosin staining, serum levels of myocardial enzymes and cardiac troponin I were detected, and the expressions of Bcl-2 and Bax were detected by real-time PCR. RESULTS AND CONCLUSION:(1) Hematoxylin-eosin staining showed that the damage degree was more severe with the time of exercise, and the high-intensity exercise groups were more severe than those in the moderate-intensity exercise groups. (2) The activity of serum glutamic-oxaloacetic transaminase and lactic dehydrogenase was significantly increased after 1-week moderate-intensity exhaustive exercise (P<0.05 or P<0.01). From the beginning of the 3-time high-intensity exhaustive exercise, the activity of glutamic-oxaloacetic transaminase and lactic dehydrogenase was significantly increased (P<0.05 or P<0.01). (3) Cardiac troponin I content change trend was basical y the same as glutamic-oxaloacetic transaminase and lactic dehydrogenase changes, but cardiac troponin I content in the moderate-intensity exhaustive exercise groups was significantly higher than that in the rest control group until 2 weeks. The Bcl-2/Bax ratios in al exercise groups were significantly lower than that in the rest control group (P<0.05 or P<0.01);those in the 1-and 3-time high-intensity exercise groups were significantly higher than in the isoprenaline group (P<0.05 or P<0.01);and those in moderate-intensity groups were higher than in the isoprenaline group (P<0.05 or P<0.01). (4) In conclusion, 2-week high-intensity and 3-week moderate-intensity exhaustive exercise can induce myocardial ischemia injury, and pathological analysis, serum levels of myocardial enzymes and cardiac troponin I can be used as the evaluation indexes, while apoptosis regulation genes just as the reference index.