苯那普利对离体大鼠缺血再灌注心肌的保护作用

目的观察苯那普利对离体大鼠缺血再灌注心肌的保护作用,初步探讨其作用机制。方法应用Langendorff装置,采用完全停灌复灌的方法制作离体大鼠心肌缺血再灌注模型。将24只SD大鼠随机等分3组:对照组(KH液持续灌注110 min),缺血再灌注组(KH液灌流20 min,停灌30 min,再灌注60 min),苯那普利组(缺血30 min,再灌注60 min,灌注液加入苯那普利10-6mol/L)。观察再灌注心律失常发生情况、血流动力学、光镜下心肌结构改变、心肌肿瘤坏死因子-α(TNF-α)免疫组织化学染色。结果与缺血再灌注组比,苯那普利组再灌注60 min内室性心动过速、心室颤动发生率降低;血流动力学指标明显改善;光镜可见炎症损伤减轻。免疫组织化学染色可见TNF-α蛋白阳性表达主要在心肌细胞胞浆苯那普利组呈弱阳性;对照组阴性;缺血再灌注组强阳性。结论苯那普利对缺血再灌注心肌具有保护作用,其机制可能与抑制TNF-α表达、减轻炎症有关。

Protective effects of benazepril during ischemia-reperfusion in isolated rats hearts

Objective To observe the protective effects of benazepril during ischemia-reperfusion in isolated rats hearts,and investigate the possible mechanism.Methods 24 male Sprague-Dawley rats were randomly divided into three groups(n=8 each): control group(perfused with a normal KH buffer at a constant flow for 110 min),ischemia-reperfusion group(perfused for 20 min by KH buffer,then the hearts were subjected to 30 min global ischemia and 60 min reperfusion),benazepril group(the benazepril was added to KH buffer and the hearts were subjected to 30 min global ischemia and 60 min reperfusion).Hearts were immediately removed and passively perfused in a Langendorff apparatus.The arrhythmias and the hemodynamic parameters were calculated.The pathologic change of myocardial was observed.The TNF-a was investigated by immunohistochemical technique.Results In benazepril group,compared with ischemia-reperfusion group,the incidence of arrhythmias was reduced,the recovery of myocardial function was improved,microscopic examination showed reduced inflammatory reponse.Immunohistochemical in sections of rats hearts showed that positive expression of TNF-a was seen in cytoplasm of cardiocytes.It showed negative reaction in control group,strong positive reaction in ischemia-reperfusion group and weak positive reaction in benazepril group. Conclusion Benazepril can protect rats hearts during ischemia-reperfusion,and the mechanism may involved down regulating the TNF-a expression and reducing the inflammatory response.