Methods:The effects of cyclosporin A (CsA) on drug sensitivity,intracellular drug accumulation and drug efflux in multidrug resistant human leukemic cell line K562/DOX were studied by MTT colorimetric assay and spectrofluorimetry.

• 方法：以环孢霉素A（CsA）作为耐药逆转剂，用MTT法体外药物敏感试验，观察CsA对多药耐药白血病细胞株K562/DOX的药物敏感性、细胞内药物的积聚和外排的影响。