Arachidonic acid can undergo ω-hydroxylation to 20-hydroxyeicosatetraenoic acid (20-HETE) or epoxidation to epoxyeicosatrienoic acids (EETs) by specific cytochrome P450 (CYP) enzymes expressed in brain.The ω-hydroxylase enzyme CYP 4A is expressed in neurons and cerebral vascular smooth muscle, where 20-HETE causes constriction.Inhibition of ω-hydroxylase activity protects neurons from focal and global cerebral ischemia, intracerebral hemorrhage, and traumatic brain injury.