EDHF (endothelium-derived hyperpolarizing factor) is an unidentified mediator released from vascular endothelial cells in response to acetylcholine and bradykinin which is distinct from the NOS- (nitric oxide) and COX-derived (prostacyclin) vasodilators. Cytochrome P450 (CYP450) metabolism of polyunsaturated fatty acids produces epoxides such as (±)14(15)-EpETrE which are prime candidates for the actual active mediator. However, the CYP450 metabolites of eicosapentaenoic acid and docosahexaenoic acid have been little studied relative to arachidonate epoxygenase metabolites. (±)19(20)-EpDPA is a DHA epoxygenase metabolite, derived via epoxidation of the ω-3 double bond of DHA. The EDHF activity of (±)19(20)-EpDPA has not yet been determined. The epoxygenase metabolites of DHA have also been detected in a mouse inflammation model.
19R(20S)-EpDPA is an oxylipin and a metabolite of docosahexaenoic acid .1,2It is formed from DHA by various cytochrome P450 (CYP) isoforms in a stereoselective manner.219R(20S)-EpDPA (30 nM) prevents calcium-induced increases in the spontaneous beating of isolated neonatal rat cardiomyocytes (NRCMs).3 1.Cinelli, M.A., Yang, J., Scharmen, A., et al.Enzymatic synthesis and chemical inversion provide both enantiomers of bioactive epoxydocosapentaenoic acidsJ. Lipid Res.59(11)2237-2252(2018) 2.Lucas, D., Goulitquer, S., Marienhagen, J., et al.Stereoselective epoxidation of the last double bond of polyunsaturated fatty acids by human cytochromes P450J. Lipid Res.51(5)1125-1133(2010) 3.Burke, J.E., and Dennis, E.A.Phospholipase A2 structure/function, mechanism, and signalingJ. Lipid Res.50(Suppl)S237-S242(2009)