KATP通道在参附注射液减轻大鼠心肌缺血再灌注损伤中的作用

Role of KATP channel in Shenfu injectio on myocardium against ischemia-reperfusion in rats

目的研究KATP通道在参附注射液（SFI）减轻大鼠心肌缺血再灌注损伤中的作用。方法24只SD大鼠,雌雄不拘,体重240～320 g,随机分为4组（n=6）：对照组（C组）、缺血再灌注组（I/ R组）、SFI组和SFI＋KATP通道阻滞剂格列苯脲组（SG组）。C组仅穿线不结扎左冠状动脉前降支,穿线后静脉输注生理盐水8 ml/kg。采用结扎左冠状动脉前降支40 min再灌注120 min制备心肌缺血再灌注损伤模型。SFI组缺血前15 min静脉输注SFI 8 ml/kg,SG组给予格列苯脲0．33 mg/kg和SFI 8 ml/ kg。再灌注120 min后从心尖穿刺抽血,测定血清cTnI与IL-6浓度,抽血后立即取心肌组织,测定心肌组织SOD活性、MDA含量、TNF-α表达,并在电镜下观察心肌超微结构。结果与C组比较,I/R组心肌SOD活性降低,心肌MDA、TNF-α和血清IL-6、cTnI水平升高（P＜0．05）;与I/R组比较,SFI组、SG组心肌SOD活性升高,心肌MDA、TNF-α和血清cTnI、IL-6水平降低（p＜0．05）;SG组与SFI组比较上述指标差异无统计学意义（P＞0．05）。SFI组与SG组心肌超微结构损伤程度明显轻于I/R组。结论参附注射液可以减轻大鼠心肌缺血再灌注损伤,其作用机制与KATP通道的激活无关。

Objective To study the role of KATP channel in Shenfu injectio （SFI） on myocardium against ischemia-reperfusion （I/R） in rats. Methods Twenty-four adult SD rats of both sexes weighing 240-320 g were used in this study. The animals were tracheotomized, intubated and mechanically ventilated under urethane anesthesia. Myocardial ischemia-reperfusion was produced by temporary occlusion of the anterior descending branch of left coronary artery for 40 min followed by 120 min reperfusion. The animals were randomly divided into 4 groups （ n = 6 each） ： control （group C） ; group I/R; SFI ＋ I/R （group SFI） and SFI ＋ glibenclamide ＋ I/R （group SG）. In group SFI and group SG, SFI 8 ml/kg was given intravenously 15 min before I/R. In group SG glibenclamide 0.33 mg/kg was given intravenously 15 min before I/R together with SFI. At 120 min of reperfusion blood samples were taken from hearts for determination of serum cTnI and IL-6 concentrations and hearts were immediately removed for microscopic examination and determination of SOD activity, MDA content and TNF-α expression in myocardium. Results SOD activity in myocardimn was significantly lower and MDA content and TNF-α expression in myocardium and sermn IL-6 and cTnI concentrations were significantly higher in group I/R than in group C. These I/R-induced changes were attenuated in group SFI and group SG, but there was no significant difference between group SFI and group SG. Electron microscopic examination showed that the mitochondrion, sarcoplasmic reticulum and myofilament and capillary endothelial cell injuries were much slighter in group SFI and group SG than in I/R group.Conclusion KATP channel does not play an important role in the protective effect of SFI on myocardium against I/R in rats.