CHARACTERISTICS OF 4 FRIEND-LEUKEMIA CELL SUBLINES RESISTANT TO ADRIAMYCIN

Resistance of Friend murine erythroleukemia cells was induced ol selec ted by continuous stepwise exposure to adriamycin (ADM). The resistanc e index (R.I.) varied with different ''mdr type'' drugs, even when the compounds were closely related as ADM and daunorubicin (DNR). The cel l uptake of anthracycline, evaluated by flow cytometry (FCM), was bett er correlated with the R.I. than the HPLC assessment. The quantitative cytology showed nuclear changes (size and Color distribution); all th e modifications were in part dependent on the degree of resistance. Th is study showed that the graded resistant sublines differed in their r esistant phenotypes apart from their different degree of resistance.