Effect of N-acetoxy-methylaminoazobenzene and 3'-methyl-4-dimethylaminoazobenzene on cloned rat liver cells with special reference to cellular morphology and growth capacity

Cloned rat liver cells were treated with an ultimate carcinogen, N-acetoxy-methylaminoazobenzene(AcMAB) and 3'-methyl-4-dimethylaminoazobenzene(3'-Me-DAB) then various biological characters of the cells including tumorigenicity were examined. In regard to back-transplantation, after 11 days of experiments, a high concentration (5x10(-4)M) of AcMAB-treated cells formed tumors in one out of two rats. And a low concentration(1x10(-4)M) of AcMAB or 3'-Me-DAB-treated cells and untreated control cells did not form tumors. After 99 days of experiments, tumor formation was observed not only with the high concentration of AcMAB-or 3'-Me-DAB-treated cells but also with untreated control cells. AcMAB-treated cells had altered morphology and growth properties in vitro compared to 3'-Me-DAB-treated cells and untreated control cells. These results suggest an ultimate character of AcMAB, especially from the view point of tumor-forming capacity