Arachidonic acid inhibits epithelial Na channel via cytochrome P450 (CYP) epoxygenase-dependent metabolic pathways.

We used the patch-clamp technique to study the effect of arachidonic acid (AA) on epithelial Na channels (ENaC) in the rat cortical collecting duct (CCD). Application of 10 microM AA decreased the ENaC activity defined by NPo from 1.0 to 0.