Polyamine metabolism in P388 leukemia cells and in ascites tumor-bearing mice

Alterations in ornithine decarboxylase (ODC) activity and in the polyamine and nucleic acid (RNA and DNA) concentrations were studied in P388 leukemia cells and in the host liver at different times after intraperitoneal inoculation of 5 X 10(6) tumor cells into BDF1 mice. ODC activity of leukemia cells had a maximum at day 5 after tumor transplantation. Cellular spermidine concentration declined significantly during the first 5 to 6 days. The RNA concentration of tumor cells changed parallel to that of spermidine. In the livers of ascites tumor-bearing mice ODC activity was 5- to 20-fold of control and had a maximum at days 5 to 6 after tumor cell inoculation. Spermidine concentration in the host liver increased, whereas spermine decreased gradually with tumor growth.