依达拉奉呈时间依赖性保护大鼠心肌缺血再灌注后肺损伤

目的探讨依达拉奉对大鼠心肌缺血再灌注诱发肺损伤的保护是否呈时间依赖性。方法 Wistar大鼠30只,随机分为5组:假手术组(S组)、心肌缺血再灌注组(IR组)、依达拉奉组(E1、E2和E3组),3组分别于再灌注后2h、再灌注后1h和再灌注前1min注射依达拉奉10mg/kg。处死大鼠,取肺组织、支气管肺泡灌洗液和血清,测定血清肌酸激酶同工酶(CK-MB)浓度,计算肺通透性指数(PPI)、测定肺组织β-防御素-2(BD-2)mRNA表达、BD-2和肿瘤坏死因子(TNF)-α蛋白的含量。结果与S组比较,IR、E1、E2和E3组血清CK-MB活性、PPI升高,肺组织BD-2 mRNA、BD-2和TNF-α蛋白表达上调。与IR组比较,E1、E2和E3组上述指标均下调。与E1组比较,E2组下调,差异有统计学意义;与E2组比较,E3组下调,差异有统计学意义。结论依达拉奉呈时间依赖性减轻心肌缺血再灌注诱发大鼠肺损伤。

Edaravone protects the lung injury induced by myocardial ischemia-reperfusion through time-dependent effects

Objective To observe the time-dependent effects about edaravone using as a postcondtioning for myocardial I/R on the lung injury of rats. Methods Thirty male Wistar rats weighing 250-300g were randomly allo-cated to one of 5 groups （n=6 each） ： group I sham operation （S）, group Ⅱ myocardial ischemia reperfusion（I/R）, group Ⅲ edaravone 10mg/kg given after 2h of reperfusion （E1）, group Ⅳedaravone given after lh of reperfusion （E2）, group Ⅴ edaravone given lmin before reperfusion. Myocardial I/R was predueed by occlusion of left anterior descend- ing coronary artery （LAD）. LAD were occluded for 45 rain followed by 3b reperfusion in all groups. Suture needle threaded through LAD but not ligated in S. All animals were sacrificed by exsanguinations at the end of 3h reperfu-sion. The blood, lung tissues and bronchoalveolar lavage （BAL） fluid were collected for determination of MB isoenzyme of creatine kinase （CK-MB） and pulmonary permeability index （PPI）, BD-2 and TNF-α content （by Western-bloting）, BD-2mRNA expression （by RT-PCR）. Results The levels of serum CK-MB and PPI were all significantly elevated in groups IR, E1, E2 and E3 compared with the group S. The BD-2mRNA expression were significantly higher in groups IR, E1, E2 and E3 than in group S. Edaravone was used earlier, the expression of BD-2 and TNF-α became less. Conclusion BD-2 gene expression in the lung tissue is up-regulated after myocardial I/R in rats. The protective ef-fects of edaravone expressed time-dependent.