Liver tumors induced by 4-dimethylaminoazobenzene: experimental basis for a chemical carcinogenesis concept.

In animals fed 4-dimethylaminoazobenzene there are modifications in the distribution of extra- and intracellular cations in liver. The correlation between the cell ionic permeability changes and the induction of cholangiocarcinoma or hepatoma is analyzed at the light of the histological and biochemical findings. A new concept of chemical carcinogenesis is stated in which the increase of passive Ca2+-influx produces mitochondria damage associated with permanent modifications of the structural and functional characteristics of the cell membranes as well as of the genetic mechanisms controlling cell division.