bradykinin (15)

Bradykinin (1-5), a major stable metabolite of Bradykinin, is formed by the proteolytic action of angiotensin-converting enzyme (ACE). The bradykinin (BK) fragment (1-5) (RPPGF) is one of the most stable naturally occurring metabolites.

Arachidonic acid is metabolized in the vascular endothelium to epoxytrienoic acids (EETs or EpETrEs) by cytochrome P450 enzymes. The EETs are released in response to acetylcholine, bradykinin, arachidonic acid, or cyclic stretch. (±)14(15)-EET-SI is the methyl sulfonamide analog of 14(15)-EET. This substitution results in a metabolically more stable compound because it is not sensitive to β-oxidation or membrane esterification. (±)14(15)-EET-SI is equipotent to 14(15)-EET in vascular agonist activity as measured by relaxation of precontracted bovine coronary arteries. In addition, 14(15)-EET and the methyl sulfonamide analog both stimulate tyrosine phosphorylation and induce mitogenesis in renal epithelial cells.

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.[1],[2]Cytochrome P450 (CYP450) metabolism of polyunsaturated fatty acids produces epoxides such as (±)14(15)-EET which are prime candidates for the actual active mediator.[3] However, the CYP450 metabolites of eicosapentaenoic acid and docosahexaenoic acid 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.[4]

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.