Comparative biochemistry of drug metabolism by azo and nitro reductase.

Abstract

The ability of enzymes in the liver of fish, amphibia, reptile, bird, and mammals to reduce azo and nitro compounds was studied. Azo reductase was present in the elasmobranch and both enzyme systems were present in the teleost. Amphibia have only azo reductase, whereas both azo and nitro reductase are present in reptiles, birds, and mammals. These findings suggest that the reductive enzymes may be of a more primitive nature than the oxidative enzymes that metabolize drugs.