The effects of single administration of an antitumor platinum compound on ornithine decarboxylase activity in certain tissues of mice bearing L1210 leukemia.

A single dose of cis-dichloro(dipyridine)platinum(II) (cis-PPC), when given to BDF1 mice bearing 1-day-old L1210 leukemia, suppressed the increase of spleen and liver ornithine decarboxylase (ODC) activity which occurs concomitantly with development of the leukemia. The inhibition of ODC, the rate-limiting enzyme in polyamine synthesis, appeared to correlate with the prolonged chemotherapeutic efficacy of a single dose of the platinum complex. These observations suggest an additional mechanism by which platinum complexes express their antitumor actions and, in addition, support the view that polyamine synthesis and excretion patterns can be used as predictors of chemotherapeutic response.