The same three hepatic oxidative enzymes discussed above are also expressed in the brain. However, unlike in the liver, the primary enzyme responsible for the first oxidative step from ethanol to acetaldehyde in the brain is catalase, accounting for approximately 60% of ethanol metabolism (at least in rodents). This is followed by Cytochrome P-450 (CYP2E1), while ADH plays only a minor role (135) (Figure 5).
