Ratio of polyamine synthesis and oxidation enzymes during cell proliferation and differentiation

Difluoromethylornithine (DFMO) was studied for its effect on the aminoxidase activity in the culture media during proliferation and differentiation of mouse fibroblasts. Single introduction of difluoromethylornithine into the culture medium increases the polyamine oxidase activity during 12 to 24 hours after the action. In the subsequent periods DFMO in 0.1 to 1 mM concentrations inhibits the proliferation and differentiation, but 0.01 mM concentration leads to their acceleration, which correlates with higher or lower aminoxidase activities respectively in the culture media.