Ouvrard-Pascaud A, Madec A, Richard V, Bellien J. Soluble epoxide hydrolase inhibition improves coronary endothelial function and prevents the development of cardiac alterations in obese insulin-resistant mice. Am J Physiol Heart Circ Physiol 308: H1020 -H1029, 2015. First published February 25, 2015; doi:10.1152/ajpheart.00465.2014.-This study addressed the hypothesis that inhibiting the soluble epoxide hydrolase (sEH)-mediated degradation of epoxy-fatty acids, notably epoxyeicosatrienoic acids, has an additional impact against cardiovascular damage in insulin resistance, beyond its previously demonstrated beneficial effect on glucose homeostasis. The cardiovascular and metabolic effects of the sEH inhibitor trans-4- [4-(3-adamantan-1-ylureido)-cyclohexyloxy]-benzoic acid (t-AUCB; 10 mg/l in drinking water) were compared with those of the sulfonylurea glibenclamide (80 mg/l), both administered for 8 wk in FVB mice subjected to a high-fat diet (HFD; 60% fat) for 16 wk. Mice on control chow diet (10% fat) and nontreated HFD mice served as controls. Glibenclamide and t-AUCB similarly prevented the increased fasting glycemia in HFD mice, but only t-AUCB improved glucose tolerance and decreased gluconeogenesis, without modifying weight gain. Moreover, t-AUCB reduced adipose tissue inflammation, plasma free fatty acids, and LDL cholesterol and prevented hepatic steatosis. Furthermore, only the sEH inhibitor improved endothelium-dependent relaxations to acetylcholine, assessed by myography in isolated coronary arteries. This improvement was related to a restoration of epoxyeicosatrienoic acid and nitric oxide pathways, as shown by the increased inhibitory effects of the nitric oxide synthase and cytochrome P-450 epoxygenase inhibitors L-NA and MSPPOH on these relaxations. Moreover, t-AUCB decreased cardiac hypertrophy, fibrosis, and inflammation and improved diastolic function, as demonstrated by the increased E/A ratio (echocardiography) and decreased slope of the end-diastolic pressure-volume relation (invasive hemodynamics). These results demonstrate that sEH inhibition improves coronary endothelial function and prevents cardiac remodeling and diastolic dysfunction in obese insulin-resistant mice. insulin resistance; soluble epoxide hydrolase; endothelium; cardiac function ENDOTHELIAL DYSFUNCTION AND accelerated atherosclerosis, secondary to the chronic pro-inflammatory state generated by hyperinsulinemia, hyperglycemia, and dyslipidemia, play a critical role in the development of cardiovascular complications of type 2 diabetes (12,17,22). Strategies for multiple risk-factor control including glucose, lipid, and blood pressure levels have shown a clear benefit on cardiovascular outcome in type 2 diabetic patients (22, 23). However, these patients are still at increased cardiovascular risk, and new therapeutic targets are needed (22,23).In this context, pharmacological therapies targeting both the metabolic and cardiovascular abnormalities in type 2 diabetes would be ideal candidates. An emerging pharmacological app...