title: 14,15-Epoxyeicosa-5(Z)-enoic acid: a selective epoxyeicosatrienoic acid antagonist that inhibits endothelium-dependent hyperpolarization and relaxation in coronary arteries.
abstract: Endothelium-dependent hyperpolarization and relaxation of vascular smooth muscle are mediated by endothelium-derived hyperpolarizing factors (EDHFs). EDHF candidates include cytochrome P-450 metabolites of arachidonic acid, K(+), hydrogen peroxide, or electrical coupling through gap junctions. In bovine coronary arteries, epoxyeicosatrienoic acids (EETs) appear to function as EDHFs. A 14,15-EET analogue, 14,15-epoxyeicosa-5(Z)-enoic acid (14,15-EEZE) was synthesized and identified as an EET-specific antagonist. In bovine coronary arterial rings preconstricted with U46619, 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET induced concentration-related relaxations. Preincubation of the arterial rings with 14,15-EEZE (10 micromol/L) inhibited the relaxations to 14,15-EET, 11,12-EET, 8,9-EET, and 5,6-EET but was most effective in inhibiting 14,15-EET-induced relaxations. 14,15-EEZE also inhibited indomethacin-resistant relaxations to methacholine and arachidonic acid and indomethacin-resistant and L-nitroarginine-resistant relaxations to bradykinin. It did not alter relaxation responses to sodium nitroprusside, iloprost, or the K(+) channel activators (NS1619 and bimakalim). Additionally, in small bovine coronary arteries pretreated with indomethacin and L-nitroarginine and preconstricted with U46619, 14,15-EEZE (3 micromol/L) inhibited bradykinin (10 nmol/L)-induced smooth muscle hyperpolarizations and relaxations. In rat renal microsomes, 14,15-EEZE (10 micromol/L) did not decrease EET synthesis and did not alter 20-hydroxyeicosatetraenoic acid synthesis. This analogue acts as an EET antagonist by inhibiting the following: (1) EET-induced relaxations, (2) the EDHF component of methacholine-induced, bradykinin-induced, and arachidonic acid-induced relaxations, and (3) the smooth muscle hyperpolarization response to bradykinin. Thus, a distinct molecular structure is required for EET activity, and alteration of this structure modifies agonist and antagonist activity. These findings support a role of EETs as EDHFs.
authors.affiliation: Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Gauthier
authors.forename: Christina
authors.initials: C
authors.lastname: Deeter
authors.forename: U Murali
authors.initials: UM
authors.lastname: Krishna
authors.forename: Y Krishna
authors.initials: YK
authors.lastname: Reddy
authors.forename: Muralidhar
authors.initials: M
authors.lastname: Bondlela
authors.forename: J R
authors.initials: JR
authors.lastname: Falck
authors.forename: William B
authors.initials: WB
authors.lastname: Campbell
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D001562:Benzimidazoles / Q000494:pharmacology; D001578:Benzopyrans / Q000494:pharmacology; D001920:Bradykinin / Q000494:pharmacology; D002417:Cattle; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D004095:Dihydropyridines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology*; D016285:Iloprost / Q000494:pharmacology; D066298:In Vitro Techniques; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013329:Structure-Activity Relationship; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D001562:Benzimidazoles; D001578:Benzopyrans; D004095:Dihydropyridines; D014662:Vasoconstrictor Agents; C086491:NS 1619; D009599:Nitroprusside; D016718:Arachidonic Acid; C061050:bimakalim; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C040776:5,6-epoxy-8,11,14-eicosatrienoic acid; C050715:8,9-epoxyeicosatrienoic acid; C046782:14,15-epoxy-5,8,11-eicosatrienoic acid; D015126:8,11,14-Eicosatrienoic Acid; D016285:Iloprost; D001920:Bradykinin