COLCHICINE-RESISTANCE AND ENHANCEMENT OF P-GLYCOPROTEIN ACTIVITY AFTER COCULTIVATION OF DRUG-SENSITIVE CELLS WITH MULTIDRUG-RESISTANT VARIANTS

The role of cellular interactions in the resistance of Djungurian hams ter cells to colchicine (CH) and in the efficiency of P-glycoprotein f unction was studied. Mixtures of CH-resistant and CH-sensitive cells a s well as control unmixed cells were propagated for 3 days and the sen sitivity of the cells to CH was measured by colony forming assay. iden tification of individual subpopulations was possible due to genetic ma rker (6TG-resistance). The data show that the survival of CH-sensitive cells in CH-supplemented medium increased after cocultivation with CH -resistant counterparts. To measure Pgp activity the fluorescent dye R H123 and FACScan analysis were used. Pgp-mediated RH123 efflux increas ed after co-cultivation of CH-sensitive and CH-resistant cells.