Effect of chlorambucil on synthesis of protein and nucleic acids in tumor-bearing mice.

1. Following the treatment with three doses (8-16 Mg/gm each) of chlorambucil, in corporation of radioactive glycine and lysine into protein, of glycine into acid-soluble nucleotides, and of glycine, formate, adenine, and orotic acid into nucleic acids of L-l mouse tumor was inhibited in a majority of the experiments. 2. In tumors from mice of the group treated with one dose and in livers from all groups no definite change in specific activity of different fractions was seen in more than 50 per cent of samples. 3. Inhibition of incorporation of five different metabolites into protein and nucleic acids in this lymphosarcomatous tumor by chlorambucil represents a drug effect of generalized nature and raises the question whether this is a cause or an effect of inhibition of some more vital and fundamental process in the cell.