Protective effect of Tongxinluo on mini-swine model of acute myocardial infarction and reperfusion damaged by oxidative stress / 中国病理生理杂志

ABSTRACT

AIM: To assess the degree of oxidative damage during acute myocardial infarction and reperfusion, and to clarify the protective effect of Tongxinluo in mini-swine model. METHODS: Thirty mini-swines were randomized into 5 study groups sham group, model group, low dose (0.05 g·kg~(-1)·d~(-1)), medium dose (0.2 g·kg~(-1)·d~(-1)) and high dose (0.5 g·kg~(-1)·d~(-1)) of Tongxinluo groups (pretreated with Tongxinluo for 3 d). Animals except in sham group were subjected to 3 h of coronary occlusion followed by 1 h of reperfusion. Concentrations of total antioxidative capability (T-AOC), total superoxide dismutase (T-SOD), reduced glutathione (GSH) and malondialdehyde (MDA) in blood sample and the myocardium were measured. RESULTS: (1) T-AOC, T-SOD and GSH in serum significantly decreased (all P<0.05), while MDA significantly increased (P<0.01) at 3 h after AMI in comparison with those at baseline. Compared to those at 3 h after AMI, the contents of T-AOC, T-SOD and GSH at 1 h after reperfusion significantly decreased (all P<0.01), accompanied by increase of MDA (P<0.01). (2) Compared to those in normal area, levels of T-AOC, T-SOD and GSH in reperfusion myocardium decreased significantly (all P<0.01) and MDA increased significantly (P<0.01). T-AOC, T-SOD and GSH in no-reflow myocardium further decreased (all P<0.01) and MDA increased (P<0.01) as compared to those in reperfusion myocardium. (3) Compared to model group, medium dose of Tongxinluo increased the contents of T-AOC and T-SOD and reduced MDA production in serum at 3 h after AMI (all P<0.05), while medium dose of Tongxinluo increased T-SOD level at 1 h after reperfusion (P<0.05). High dose of Tongxinluo increased the levels of T-AOC and T-SOD and decreased MDA content in serum at 3 h after AMI and 1 h after reperfusion (all P<0.05). (4) The medium dose of Tongxinluo increased T-AOC content (P<0.05) and reduced MDA (P<0.05) in reperfusion myocardium, while high dose of Tongxinluo increased T-AOC, T-SOD and GSH (all P<0.05), reduced MDA (P<0.01) in reperfusion myocardium, and also increased T-AOC, T-SOD (all P<0.05), reduced MDA (P<0.01) in no-reflow area as compared to those in model group. CONCLUSION: Impairment of antioxidant defense system in vivo and imbalance of redox homeostasis in myocardium region might play an important role in the pathogenesis of no-reflow after myocardial acute infarction following reperfusion. Tongxinluo protects myocardium from reperfusion injury by improving antioxidant defense and attenuating oxidative damage.