In vivo potentiation of cis-diamminedichloroplatinum (II) antitumor activity by pretreatment with sparsomycin.

The influence of protein synthesis inhibition by sparsomycin (Sm) on in vivo cisplatin activity has been studied on BALBc X DBA2: F1 mice bearing L1210 leukemia i.p. Sm alone at the dose range from 0.5 to 3.0 mg/kg did not significantly improve animal survival. Sm potentiated cisplatin activity only when given 3 or 6 h prior to cisplatin (P less than 0.001). Sm 0.5-1.5 mg/kg 3 h prior to cisplatin resulted in a significant prolongation of animal survival (P less than 0.001) and 66% cures in each group versus 0% due to cisplatin alone. Sm pretreatment decreased weight loss due to cisplatin suggesting that it probably is able to decrease cisplatin toxicity.