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 (Item No. 50651) which are prime candidates for the actual active mediator. However, the CYP450 metabolites of eicosapentaenoic acid (EPA; Item No. 90110) and docosahexaenoic acid (DHA; Item No. 90310) have been little studied relative to arachidonate epoxygenase metabolites. (±)16(17)-EpDPA is the DHA homolog of (±)14(15)-EpETrE, derived via epoxidation of the 16,17-double bond of DHA. The EDHF activity of (±)16(17)-EpDPA has not yet been determined. The epoxygenase metabolites of DHA have also been detected in a mouse inflammation model.
1.Chataigneau, T.,Félétou, M.,Duhault, J., et al. Epoxyeicosatrienoic acids, potassium channel blockers, and endothelium-dependent hyperpolarization in the guinea-pig carotid artery. British Journal of Pharmacology 123, 574-580 (1998).