to dihydroxyeicosatrienoic acids. EETs are formed from arachidonic acid during myocardial ischemia and play a protective role against ischemic cell death. Deletion of sEH has been shown to be protective against myocardial ischemia in the isolated heart preparation. We tested the hypothesis that sEH inactivation by targeted gene deletion or pharmacological inhibition reduces infarct size (I) after regional myocardial ischemia-reperfusion injury in vivo. Male C57BL6گJ wildtype or sEH knockout mice were subjected to 40 min of left coronary artery (LCA) occlusion and 2 h of reperfusion. Wild-type mice were injected intraperitoneally with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester (AUDA-BE), a sEH inhibitor, 30 min before LCA occlusion or during ischemia 10 min before reperfusion. 14,15-EET, the main substrate for sEH, was administered intravenously 15 min before LCA occlusion or during ischemia 5 min before reperfusion. The EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid (EEZE) was given intravenously 15 min before reperfusion. Area at risk (AAR) and I were assessed using fluorescent microspheres and triphenyltetrazolium chloride, and I was expressed as I/AAR. I was significantly reduced in animals treated with AUDA-BE or 14,15-EET, independent of the time of administration. The cardioprotective effect of AUDA-BE was abolished by the EET antagonist 14,15-EEZE. Immunohistochemistry revealed abundant sEH protein expression in left ventricular tissue. Strategies to increase 14,15-EET, including sEH inactivation, may represent a novel therapeutic approach for cardioprotection against myocardial ischemia-reperfusion injury.14,15-epoxyeicosatrienoic acids; 12-(3-adamantan-1-yl-ureido)-dodecanoic acid butyl ester THE P-450 EPOXYGENASE PATHWAY metabolizes arachidonic acid into four biologically active eicosanoids, referred to as epoxyeicosatrienoic acids (5,6-, 8,9-, 11,12-, and 14,15-EET) (10). EETs play an important role in regulating tissue perfusion in both cardiac and extracardiac organs. The actions of EETs are terminated by conversion to dihydroxyeicosatrienoic acids (DHETs) by epoxide hydrolases (11). Two major epoxide hydrolases are found in mammalian tissues, the microsomal (mEH) and soluble epoxide hydrolases (sEH) (2). However, sEH is the primary enzyme involved in the in vivo metabolism of EETs (19). In addition to their vascular effects, EETs exhibit a cardioprotective effect, which has been linked to activation of the reperfusion injury salvage kinase pathway (18) and mediated in part through activation of the phosphatidylinositol 3-kinase/Akt pathway and the mitochondrial ATP-sensitive K ϩ channels (5, 15). Augmenting endogenously released EETs by inhibiting the converting enzyme sEH represents an attractive strategy to increase ischemic tolerance. Our laboratory has recently used this strategy to show that pharmacological inhibition (20) and gene deletion (21) are protective against experimental stroke in vivo. Similarly, using the isolated heart preparation, Seubert et al. (16) demonstrat...
