All issues > Volume 35(8); 1992

Original Article

J Korean Pediatr Soc. 1992;35(8):1107-1112. Published online August 15, 1992.

Effects of Adriamycin on Membrane Potential and Intracellular Sodium Activity in Canine Purkinje fibers

Chan Uhng CU Joo¹, Soo Wan SW Chae²

¹Department of Pediatrics, College of Medicine, Chonbuk Nation University, Chonbuk, Korea
²Department of Pharmacology, College of Medicine, Chonbuk Nation University, Chonbuk, Korea

Abstract

Anthracycline antibiotic adriamycin (doxorubicin) is presently considered to be a very effective chemotherapeutic agent in the treatment of many human tumors. Adriamycin induced cardiomyopathy limits its clincal use. A number of hypotheses have been proposed to explain the mechanism of cardiotoxicity with adriamycin, but none has yet been demonstrated. The effects of adriamycin on membrane potential and intracellular sodium ion activity in isolated canine Purkinje fibers were studied. The results obtained as follows. 1) Adriamycin induced hyperpolarization in diastolic membrane potential and prologed the duration of the action potential. 2) Adriamycin increased intracellular sodium ion activity. 3) With the pretreatment of ouabain, the alterations of the membrane potentials and the increased intracellular sodium ion activity caused by adriamycin were inhibited. From above results, it was suggested that the changes of the membrane potential caused by adriamycin may be the result of a drug-induced alteration in membrane coductance to K+, and that adriamycin may be a inhibitor of the Na+-K+ ATPase in isolated canine Purkinje fibers.

Keywords :Adriamycin, Membrane potential, Intracellular sodium ion activity, Purkinje fibers