Ethanol oxidation by rat brain in vivo.

Can brain metabolize ethanol? We present data demonstrating that brain catalase in conjunction with endogenous H2O2 will oxidize ethanol in vivo. The method is based on an H2O2-dependent inhibition of brain catalase in vivo by 3-amino-1,2,4-triazole and its prevention by ethanol. The irreversible inhibition of catalase by aminotriazole is known to proceed via the reaction of (catalase-H2O2) compound I with aminotriazole. Inhibition can be prevented by compounds that are oxidized by compound I. Ethanol is one such compound. Prevention of the inhibition of brain catalase in vivo by prior administration of ethanol constitutes indirect evidence for the oxidation of ethanol to acetaldehyde in rat brain. The catalase content of the tissues represented catalase in the brain parenchyma, from which erythrocytes and capillaries had been excluded. Ethanol did not alter the levels of aminotriazole in brain. These results constitute the first demonstration of ethanol oxidation by living brain.