Xenon administration during early reperfusion reduces infarct size after regional ischemia in the rabbit heart in vivo

The noble gas xenon can be used as an anesthetic gas with many of the prope rties of the ideal anesthetic. Other volatile anesthetics protect myocardia l tissue against reperfusion injury. We investigated the effects of xenon o n reperfusion injury after regional myocardial ischemia in the rabbit. Chlo ralose-anesthetized rabbits were instrumented for measurement of aortic pre ssure, left ventricular pressure, and cardiac output. Twenty-eight rabbits were subjected to 30 min of occlusion of a major coronary artery followed b y 120 min of reperfusion. During the first 15 min of reperfusion, 14 rabbit s inhaled 70% xenon/30% oxygen (Xenon), and 14 rabbits inhaled air containi ng 30% oxygen (Control). Infarct size was determined at the end of the repe rfusion period by using triphenyltetrazolium chloride staining. Xenon reduc ed infarct size from 51% +/- 3% of the area at risk in controls to 39% +/- 5% (P < 0.05). Infarct size in relation to the area at risk size was smalle r in the xenon-treated animals, indicated by a reduced slope of the regress ion line relating infarct size to the area at risk size (Control: 0.70 +/- 0.08, r = 0.93; Xenon: 0.19 +/- 0.09, r = 0.49, P < 0.001). In conclusion, inhaled xenon during early reperfusion reduced infarct size after regional ischemia in the rabbit heart in vivo.