Proteção do miocárdio isquêmico de coelho, utilizando-se perfusato enriquecido com glutation

Abstract

During cardiac surgery the cardioplegic manuver associated to high potasium concentration and hypothermia are the technics most utilized for myocardium protection during surgery. In this study we have attempted to demonstrate the protective effect of a cardioplegic solution with high potassium content associated to moderate hypothermia and high potasium content in addition to glutathione in the cardiac preservation, submitted to prolonged ischemia. We have used the isolated rabbit heart in a perfusion system inicialy described by Langendorff with a few modifications adapted for this study in our laboratory. During the first experimental protocol we evaluated the cytoprotector effect of the hyperkalemia solution combined with hypothermia at 24°C at different ischemic intervals. The results obtained during the evaluation of muscle inotropic response demonstrated an important protective effect of this solution in the cardiac tissue. The second protocol was made with the objective to determine the role of glutathion in the protective effect of the perfusate in two concentrations during ischemia at 30°C, where the physiologic function were more decreased by using potassium cardioplegia previously. When the heart was submitted to ischemia with reperfusion without glutathion we observed a 70% reduction in the inothropic response after the second period when compared to the results observed during the begining of the experiment in the same group.