Quantitative autoradiographic studies on the competition of diethylnitrosamine (DENA) and 9,10-dimethyl-1,2-benzanthracene (DMBA) in the liver cell of CBA-mice.

In CBA-mice the competition of DENA and DMBA was studied by quantitative autoradiography. During the precancerous phase in DENA-pretreated animals the rate of DMBA-incorporation into DNA/RNA and nuclear proteins was lower as compared to the controls without DENA-pretreatment. Independent of DENA-pretreatment the rate of DMBA-incorporation into the cytoplasm was significantly enhanced in hepatectomized animals. In this experiment the skin as a target organ did not show any quantitatively measurable DMBA-incorporation despite of prolonged autoradiographic exposition time.