Effects of 3'-methyl-4-dimethylaminoazobenzene and 4-aminoazobenzene on plating efficiency, mitotic index, and macromolecular synthesis of cultured liver cells.

The response of a cultured liver cell line to azo dyes was investigated by the application of 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) and 4-aminoazobenzene (AB) with observation of, in particular, the changes which occurred in plating efficiency, macromolecular synthesis and mitotic indices. The results were as follows. (1) The application of 3'-Me-DAB resulted in a decrease in size of colonies and plating efficiency of both J-5-2 cells (derived from 7-day-old rat liver tissues) and cells of the colonical clone, J-5-2cl. (2) AB caused greater inhibition of plating efficiency than did 3'-Me-DAB. (3) Both 3'-Me-DAB and AB inhibited synthesis of DNA but not of RNA or of protein. (4) AB exhibited a greater inhibitory effect on mitotic indices than did 3'-Me-DAB.