The soluble proteins from the livers of rats fed 3′-methyl-4-dimethylaminoazobenzene, 4′-methyl-4-dimethylaminoazobenzene, or 2-methyl-4-dimethylaminoazobenzene were subjected to electrophoretic analysis. In each case the major portion of the protein-bound dye migrated with the slowly migrating h components. These components were previously shown to be present in greatly reduced quantities in azo dye-induced hepatomas.
The results are interpreted to indicate that metabolic derivatives of these aminoazo dyes bind specific liver protein(s).
Aided in part by research grants from the Wisconsin Alumni Research Foundation, the National Cancer Institute of the National Institutes of Health, Public Health Service, and the American Cancer Society. The generous and valuable assistance rendered by Mrs. Betty F. Claus is gratefully acknowledged.