猪急性心肌梗死再灌注后氧化应激损伤及通心络的保护作用

目的:评价猪急性心肌梗死(AMI)再灌注后氧化应激损伤在心肌无再流中的作用以及中药通心络的保护作用和机制。方法:中华小型猪30只,随机分成假手术组、模型组、小剂量(0.05g·kg-1.d-1)、中剂量(0.2g·kg-1.d-1)和大剂量(0.5g·kg-1.d-1)通心络治疗组,每组6只。冠状动脉阻断3h,再灌注1h建立AMI再灌注模型。测定并对比AMI前、后3h和再灌注后1h血清及再灌注后正常、再灌注和无再流区心肌组织中氧化应激指标总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量的变化。结果:(1)与假手术组相比,模型组冠脉结扎3h,血T-AOC、T-SOD和GSH含量均显著降低(均P0.01),而MDA含量显著增加(P0.01),再灌注后,上述指标降低和升高更显著(均P0.01)。(2)与假手术组和正常区心肌组织相比,模型组再灌注区心肌T-AOC、T-SOD和GSH含量均显著降低(均P0.01),MDA含量则显著升高(P0.01),而无再流区上述指标降低和升高比再灌注区更显著(均P0.01)。(3)与模型组相比,中剂量通心络能显著提高AMI3h血T-AOC、T-SOD含量,降低MDA含量(均P0.05),并显著提高再灌注1h血T-SOD含量(P0.05);大剂量通心络能显著提高AMI3h和再灌注1h血T-AOC、T-SOD含量,抑制MDA生成(均P0.05)。(4)中剂量通心络仅能显著提高再灌注区T-AOC含量(P0.05),降低MDA含量(P0.05);而大剂量则显著增加再灌注区T-AOC、T-SOD和GSH含量(均P0.05),抑制MDA的合成(P0.01),并显著增加无再流区T-AOC和T-SOD含量(均P0.05),降低MDA的含量(P0.01)。结论:机体抗氧化防御功能降低和心肌局部氧化还原稳态失衡,可能是AMI再灌注后无再流发生的重要机制。中药通心络可能通过提高机体抗氧化防御能力,抑制心肌局部的氧化损伤,起到了减少无再流的作用。

Protective effect of Tongxinluo on mini-swine model of acute myocardial infarction and reperfusion damaged by oxidative stress

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.