[The use of verapamil in tests for determining the drug resistance of leukemic blasts].

To determine prognostically unfavourable groups of acute leukemia patients, the authors studied the in vitro accumulation of 3H-vincristine (Vcr) and adriamycin (ADR) as well as inclusion of 3H-cytosar (Ara-C) into marrow blast DNA from patients showing different effects of treatment. It was found resistant to induction chemotherapy increases with verapamil addition to culture medium (Vrp+ cells). ADR inclusion into Vrp+ cells was the same as that into Vrp- cells. The inclusion of 3H-Ara-C into S-phase cell DNA in the cells Vrp+ was 3 time that in the cells Vrp-. All the responders to cytosar treatment had Vrp- blasts. It is evident that evaluation of Vrp effect on 3H-Vcr accumulation under short-term culturing is able to indicate groups of patients with low probability of achieving complete remissions in response to standard regimens of Vcr, Ara-C and anthracyclines treatment.