Alcohol dehydrogenase (ADH) consists of a family of isozymes that conv
ert alcohols to their corresponding aldehydes using NAD(+) as a cofact
or The metabolism of ethanol by gastrointestinal ADH isozymes results
in the production of acetaldehyde, a highly toxic compound that binds
to cellular protein and DNA if not further metabolized to acetate by a
cetaldehyde dehydrogenase isozymes. Acetaldehyde seems to be involved
in ethanol-associated cocarcinogenesis. The metabolism of retinol and
the generation of retinoic acid is a function of class I and class IV
ADH, and its inhibition by alcohol may lead to an alteration of epithe
lial cell differentiation and cell growth and may also be involved in
ethanol-associated gastrointestinal cocarcinogenesis.