14,15-Epoxyeicosa-5(Z)-Enoic-mSI: A 14,15- and 5,6-EET antagonist in bovine coronary arteries

Kathryn M. Gauthier, Setti G. Jagadeesh, J R Falck, William B. Campbell

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

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 μmol/L, whereas, 14,15-EEZE-mSI induced maximal relaxation averaging only 7%. 14,15-EEZE-mSI (10 μmol/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 μmol/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.

Original languageEnglish (US)
Pages (from-to)555-561
Number of pages7
JournalHypertension
Volume42
Issue number4 I
DOIs
StatePublished - Oct 1 2003

Keywords

  • Acetylcholine
  • Arachidonic acids
  • Bradykinin
  • Endothelium-derived factors
  • Vasodilation

ASJC Scopus subject areas

  • Internal Medicine

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