title: Soluble epoxide hydrolase-dependent regulation of myogenic response and blood pressure.
abstract: Epoxyeicosatrienoic acids (EETs) are metabolites of arachidonic acid via cytochrome P450 (CYP)/epoxygenases. EETs possess cardioprotective properties and are catalyzed by soluble epoxide hydrolase (sEH) to dihydroxyeicosatrienoic acids (DHETs) that lack vasoactive property. To date, the role of sEH in the regulation of myogenic response of resistant arteries, a key player in the control of blood pressure, remains unknown. To this end, experiments were conducted on sEH-knockout (KO) mice, wild-type (WT) mice, and endothelial nitric oxide synthase (eNOS)-KO mice treated with t-TUCB, a sEH inhibitor, for 4 wk. sEH-KO and t-TUCB-treated mice displayed significantly lower blood pressure, associated with significantly increased vascular EETs and ratio of EETs/DHETs. Pressure-diameter relationships were assessed in isolated and cannulated gracilis muscle arterioles. All arterioles constricted in response to increases in transmural pressure from 60 to 140 mmHg. The myogenic constriction was significantly reduced, expressed as an upward shift of pressure-diameter curve, in arterioles of sEH-KO and t-TUCB-treated eNOS-KO mice compared with their controls. Removal of the endothelium, or treatment of the vessels with PPOH, an inhibitor of EET synthase, restored the attenuated pressure-induced constriction to the levels similar to those observed in their controls but had no effects on control vessels. No difference was observed in the myogenic index, or in the vascular expression of eNOS, CYP2C29 (EET synthase), and CYP4A (20-HETE synthase) among these groups of mice. In conclusion, the increased EET bioavailability, as a function of deficiency/inhibition of sEH, potentiates vasodilator responses that counteract pressure-induced vasoconstriction to lower blood pressure.
authors.affiliation: Department of Physiology, New York Medical College, Valhalla, New York;
authors.forename: Dong
authors.initials: D
authors.lastname: Sun
authors.forename: Azita J
authors.initials: AJ
authors.lastname: Cuevas
authors.forename: Katherine
authors.initials: K
authors.lastname: Gotlinger
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Hwang
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Hammock
authors.forename: Michal L
authors.initials: ML
authors.lastname: Schwartzman
authors.forename: An
authors.initials: A
authors.lastname: Huang
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D001160:Arterioles / Q000502:physiology; D001565:Benzoates / Q000494:pharmacology; D001794:Blood Pressure / Q000502:physiology*; D002316:Cardiotonic Agents; D042926:Cytochrome P-450 CYP4A / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D000072467:Cytochrome P450 Family 2; D004730:Endothelium, Vascular / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004851:Epoxide Hydrolases / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D024510:Muscle Development / Q000502:physiology*; D052250:Nitric Oxide Synthase Type III / Q000172:deficiency / Q000502:physiology; D010671:Phenylurea Compounds / Q000494:pharmacology; D014661:Vasoconstriction; D014664:Vasodilation
chemical_list: C572961:4-(4-(3-(4-trifluoromethoxy-phenyl)ureido)cyclohexyloxy)benzoic acid; D001095:Arachidonic Acids; D001565:Benzoates; D002316:Cardiotonic Agents; D004791:Enzyme Inhibitors; D010671:Phenylurea Compounds; D003577:Cytochrome P-450 Enzyme System; D052250:Nitric Oxide Synthase Type III; C086292:Cyp2c29 protein, mouse; D000072467:Cytochrome P450 Family 2; D042926:Cytochrome P-450 CYP4A; D004851:Epoxide Hydrolases
keywords: arterioles; endothelium; epoxyeicosatrienoic acids; myogenic response; soluble epoxide hydrolase