Infarct limitation of the second window of protection in a conscious rabbit model.
Infarct limitation of the second window of protection in a conscious rabbit model.
复制标题
清醒兔子模型中第二保护窗的梗死限制。
DOI：
10.1016/0008-6363(96)00026-0
复制
发表时间：
1996
影响因子：
10.8
通讯作者：
Cohen,MV
中科院分区：
文献类型：
--
作者：
Yang,XM;Baxter,GF;Heads,RJ;Yellon,DM;Downey,JM;Cohen,MV
ObjectivesMyocardial protection associated with ischemic preconditioning (PC) wanes within an hour or two. It has recently been observed, however, that a delayed phase of protection appears about 24 h after ischemic PC in anesthetized rabbits and dogs which might be related to synthesis of cytoprotective proteins. We tested whether a second window of protection could be induced in conscious rabbits.MethodsRabbits chronically instrumented with a coronary artery occluder and ECG electrodes experienced a 30-min coronary occlusion followed by 3 h reperfusion. Infarct size was measured with triphenyltetrazolium chloride.Results35.7 ± 2.3% of the risk zone infarcted in control animals. PC with 4 cycles of 5-min coronary occlusion/10-min reperfusion 24 h prior to the 30-min ischemia decreased infarction to 24.1 ± 1.4% of the risk zone (P< 0.01). During the 30-min occlusion 3 of 7 non-PC rabbits developed ventricular fibrillation, while this arrhythmia did not occur in the 7 PC animals (P< 0.1). Myocardial hsp70 content in PC rabbits was twice that in controls. Collateral blood flow was not different in the two groups.ConclusionsA second window of protection exists in conscious rabbits which minimizes both infarction and arrhythmias, and cytoprotective protein content is increased in the myocardium of protected animals.
