Microsomal ethanol oxidation in the colonic mucosa of the rat. Effect of chronic ethanol ingestion.

A microsomal ethanol oxidizing system (MEOS) is present in the colonic mucosa of the rat. This MEOS metabolizes ethanol to acetaldehyde at the physiological pH of 7.4. Alcoholdehydrogenase or catalase are not involved in the reaction. The Michaelis Menten constante of the reaction is 13.7±0.3 mM and the maximal velocity is 219±30 pmoles acetaldehyde/mg microsomal protein x min.