简介：Objective:Tounderstandwhetherverapamil(VER)resistancedevelopmentinthemultidrug-resistantcelllineanditsmechanism.Methods:K562/ADM/VERcellsublineresistanttoverapamilwasestablishedthroughagradualincreaseofVERconcentrationinthemedia.MTTmethodwasusedtoassayresistancetoVER,crossresistancetodipyriamole(DPM),cyclosporinA(CsA)inthecells,andHPLCandspectrofluorometertodetectintracellularaccumulationofVERorADMrespectively,aswellasS-Pimmunocytochemicaltechniquefordetectionofgenesexpression.Results:Itwereobservedthat7.9-foldincreaseinVERresistance,significantlyreducedintracellularaccumulationofVERorADMandalsodevelopacrossresistancetoDPMandCsAinK562/ADM/VERcells,comparedwithitsparentcell,K562/ADM.High-levelofp-glycoprotein(pgp),middle-levelofp53,p16,waspresentintwocelllineswithoutexpressionofGSTPI,C-myc,C-myc,C-fosandC-erbB-2.Bc1-2proteinexpressionwasfoundonlyinK562/ADMcells.Conclusion:K562/ADMcellswerecapableofbeinginducedtodevelopresistancetoVER.