Figure 1. Schematic diagram of the experimental protocol. All dogs were subjected to 60 min of left anterior descending coronary artery (LAD) occlusion and 3 h of reperfusion. Control dogs received no intervention before LAD occlusion and reperfusion. Preconditioned (PC) dogs underwent four 5-min LAD occlusions interspersed with 5-min periods of reperfusion before prolonged LAD occlusion. The actions of isoflurane to decrease myocardial infarct size when administered until 5 min before prolonged LAD occlusion (I) and in the presence of ischemic preconditioning (I + PC) were examined in separate groups. The ability of isoflurane to mimic the memory (M) of ischemic preconditioning was investigated in dogs in which isoflurane was discontinued 30 min before prolonged LAD occlusion and reperfusion (I + M). The mechanism of isoflurane-induced preconditioning was investigated in dogs pretreated with glyburide in the presence (I + M + GLB) or absence (GLB) of isoflurane.