14,15-epoxyeicosa-5(Z)-enoic-mSI: a 14,15- and 5,6-EET antagonist in bovine coronary arteries. Hypertension 2003 Oct;42(4):555-61
Date
09/04/2003Pubmed ID
12953017DOI
10.1161/01.HYP.0000091265.94045.C7Scopus ID
2-s2.0-0141962643 (requires institutional sign-in at Scopus site) 50 CitationsAbstract
Endothelium-dependent hyperpolarizations and relaxation of vascular smooth muscle induced by acetylcholine and bradykinin are mediated by endothelium-derived hyperpolarizing factors (EDHFs). In bovine coronary arteries, arachidonic acid metabolites, epoxyeicosatrienoic acids (EETs), function as EDHFs. The 14,15-EET analog 14,15-epoxyeicosa-5(Z)-enoic-methylsulfonylimide (14,15-EEZE-mSI) was synthesized and tested for agonist and antagonist activity. In U46619-preconstricted bovine coronary arterial rings, 14,15-, 11,12-, 8,9-, and 5,6-EET induced maximal concentration-related relaxation averaging 75% to 87% at 10 micromol/L, whereas, 14,15-EEZE-mSI induced maximal relaxation averaging only 7%. 14,15-EEZE-mSI (10 micromol/L) preincubation inhibited relaxation to 14,15- and 5,6- EET but not 11,12- or 8,9- EET. 14,15-EEZE-mSI also inhibited indomethacin-resistant relaxation to arachidonic acid and indomethacin-resistant and l-nitroarginine-resistant relaxation to bradykinin and methacholine. It did not alter the relaxation to sodium nitroprusside, iloprost, or the K+ channel openers bimakalim or NS1619. In cell-attached patches of isolated bovine coronary arterial smooth muscle cells, 14,15-EEZE-mSI (100 nmol/L) blocked the 14,15-EET-induced (100 nmol/L) activation of large-conductance, calcium-activated K+ channels. Mass spectrometric analysis of rat renal cortical microsomes incubated with arachidonic acid showed that 14,15-EEZE-mSI (10 micromol/L) increased EET concentrations while decreasing the concentrations of the corresponding dihydroxyeicosatrienoic acids. Therefore, 14,15-EEZE-mSI inhibits relaxation to 5,6- and 14,15- EET and the K+ channel activation by 14,15-EET. It also inhibits the EDHF component of bradykinin-induced, methacholine-induced, and arachidonic acid-induced relaxation. These results suggest that 14,15- or 5,6 -EET act as an EDHF in bovine coronary arteries.
Author List
Gauthier KM, Jagadeesh SG, Falck JR, Campbell WBAuthor
William B. Campbell PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
8,11,14-Eicosatrienoic AcidAnimals
Arachidonic Acid
Cattle
Coronary Vessels
Culture Techniques
Patch-Clamp Techniques
Potassium Channels, Calcium-Activated
Rats
Sulfonamides
Vasodilator Agents