[Drug sensitivity and cellular potassium release of cancer cells]

The tumor lysis syndrome, consisting of severe hyperkalaemia, hyperphosphatemia and hypocalcemia, occurs after the effective induction chemotherapy of rapidly growing responsive tumors. The metabolic abnormalities are thought to be secondary to the release of intracellular products. For the purpose to examine quantitative relation between cellular potassium release and drug sensitivity, we compare the inhibition of valinomycin (K-ionophore)-induced-hyperpolarization (MPR Test) with that of succinate dehydrogenase activity (SDI test). Our present research revealed a high correlation of MPR test and SDI test, and suggested the significant association of drug sensitivity with potassium release from cancer cells. Therefore, it seems appropriate to monitor potassium levels when therapy of a responsive tumor is initiated.