Effect of Low-Level Laser Irradiation Preconditioning on Milieu of Infarcted Myocardium in Experimental Rats / 中国循环杂志

ABSTRACT

Objective: To explore the effect of low-level laser irradiation (LLLI) preconditioning on milieu of infarcted myocardium in experimental rats. Methods: The myocardial infarction (MI) model was established by left anterior descending (LAD) artery ligation in female rats. 3 weeks later, the qualified MI rats were randomly divided for 3 groups ① LLLI preconditioning group, the rats received thoracotomy for LLLI by a 635nm, 5mW diode laser with the energy density of 0.96 J/cm2 for 150 seconds, n=26. ② Control group, the rats received thoracotomy for daylight irradiation, n=27. ③ Sham operation group, the rats received thoracotomy without LAD ligation, n=24. The Expressions of myocardial vascular endothelial growth factor (VEGF), glucose-regulated protein 78 (GRP78), superoxide dismutase (SOD) and malondialdehyde (MDA) were evaluate by real time-PCR, Western blot analysis and other relevant laboratory test at 1 hour, 1 day and 1 week after treatment. The myocardial cell apoptosis was examined by TUNEL staining, and left ventricular function was detected by echocardiography. Results: LLLI preconditioning obviously increased the myocardial VEGF, GRP78 expression and SOD activity, decreased MDA production; while it could not really improve the myocardial cell apoptosis at peri-infarcted area and left ventricular function in experimental rats. Conclusion: LLLI preconditioning may improve the milieu of infarcted myocardium via decreasing the oxidative stress in experimental rats.