Abstract
The effects of copper and riboflavin on 4-dimethylaminoazobenzene (DAB) azo reductase activity and 1, 2-dimethyl-4-(p-carboxyphenylazo)-5-hydroxybenzene (CPA) azo reductase activity in rat liver were investigated. In the liver microsome both riboflavin content and DAB azo reductase activity were not significantly increased in the groups given the diet supplemented with 20 mg or 50 mg of riboflavin/100 g of diet as a riboflavin-excessive diet, but was significantly increased in the groups given the diet supplemented with copper. In the riboflavin-deficient diet group not only riboflavin but copper was also decreased. DAB azo reductase activity in the groups given the copper-supplemented diet was increased more than that in each group of the same concentration of riboflavin diet. The increase of CPA azo reductase activity was almost in parallel with that of DAB azo reductase activity in the groups given the diet supplemented with copper.