【摘要】 目的探讨建立无呼吸机支持,短时间反复冷冻法制作大鼠急性心肌梗死(AMI)模型方法。方法将60只Wistar大鼠(雄雌各半),按照总共冷冻损伤时间随机分3组:15s组(5s/次,共3次);25s组(5s/次,共5次);40s组(5s/次,共8次),各20只。胸骨左缘前外侧第4肋间进入胸腔充分暴露心脏,用浸入液氮之直径6mm铜充分接触左室游离壁,持续时间5s/次,随即闭合胸腔,待自主呼吸恢复正常后,按分组情况再次原位反复共3、5次或8次进行心肌冷冻损伤。观察术中、术后28d内大鼠存活率及术后28d行病理切片Masson染色计算梗死面积。结果①3组病理学检测均为透壁梗死,面积超过20%,心肌坏死完全且边界清楚。②15s组存活率(16/20)较40s组(5/20)高(P<0.05),但其梗死面积(28.2775±5.1926)%较40s组梗死面积(37.7680±10.5644)%小(P<0.05)。③25s组存活率(9/20)(P>0.05)和梗死面积(31.3800±6.4960)%(P>0.05)与其他2组比较无明显差异。④40s组梗死面积变化范围较其他2组大,且存活率较低。25s组较15s组操作繁琐且死亡有增多趋势。结论无呼吸机支持、短时间、反复3次超低温冷冻左室游离壁15s可以建立稳定的大鼠AMI模型。更多还原

【Abstract】 Objective To explore a new method of establishing rat model of acute myocardial infarction by off ventilator support,spurt and repeated cryoinjury.Methods Sixty Wistar rats with male and female in half were randomized into three experimental groups according to cryoinjury time with 20 rats in each group:15-second group(cryoinjury for 5 s each time,three times in total),25-second group(5 s each time,five times in total)and 40-second group(5 s each time,eight times in total).The heart was exposed through a 1.0-to 1.5-cm left lateral thoracotomy.Cryoinjury of the LV free wall(LVFW)was performed by applying for 5 s a round copper probe of 6-mm in diameter immersed in liquid nitrogen for 5 min to reach-190 ℃,then the thoracic cavity was closed immediately.When the rats’ breath restored,the cryoinjury of the LVFW in situ was repeatedly to ensure a transmural injury according to the protocol.The survival rate during operation and in 28 days after operation was observed.Also infarct size was observed by heart pathological section stained with Masson’s trichrome on day 28 after operation.Results Infarct size in all three groups was larger than 20% signified by transmural injury,and completely myocardiolysis and distinct infarct boundary were observed.The survival rate was 16/20 in 15-second group,5/20 in 40-second group(P<0.05)and the infarct size was(28.277 5±5.192 6)% in 15-second group,(37.768 0±10.564 4)% in 40-second group(P<0.05).The survival rate and infarct size in 25-second group was 9/20 and(31.380 0± 6.496 0)%(P>0.05 vs 15-second group and 40-second group).The infarct size in 40-second group was larger than the other two groups(standard deviation:10.564 4% vs 5.192 6%,6.496 0% in 15,25-second group,respectively)and its survival rate was lowest.The procedure of 25-second group was more complicated and had a tendency of higher death rate than that in 15-second group.Conclusion Using spurt,repeated ultra low temperature cryoinjury for 15 s may be an ideal method to establish the rat model of acute myocardial infarction.更多还原