The Protective Effects Of Cardiac Ischemic Preconditioning On Lung In Cardiac Operation With Cardiopulmonary Bypass

Objective: In 1986 Murry et al. first introduced the concept of ischemic preconditioning, with the research in this phenomenon peoples found the protective effects of preconditioning not only on the organs itself but on the others. In this comparative study, cardiopulmonary bypass (CPB) model of myocardial ischemia-reperfusion was established with Yorkshire pig to show the effects of preconditioning on lung and study the possible mechanism.Methods: 18 Yorkshire pigs either sex weighting 5-40kg were divided into three groups. The pigs were fasted for 24 hours and prepared for study. Group1(CPB group=6):CPB was conducted without aortic cross-clamping(ACC);Group2(I/R group=6):a run pump for 45min prior to the ACC, the temperature was kept normotherimia(39℃)during this period, then with 90min ACC followed by 120min reperfusion; Group3(IP group=6): three cycles of ischemia for 5min, each followed by 10min of reperfusion before ACC and then with 90min ACC followed by 120min reperfusion.Homodynamic variables were collected at the following time points: before CPB,30min after reperfusion, 90min after...