All issues > Volume 34(5); 1991

Original Article

J Korean Pediatr Soc. 1991;34(5):677-681. Published online May 31, 1991.

The effects of adriamycin on twitch force and membrane potential in an isolated Guinea-pig papillary muscle.

Chan Uhng Joo¹, Pyung Han Hwang¹, Jung Soo Kim¹, Hee Cheol Yu², Soo Wan Chae²

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

Received: October 28, 1990;  Accepted: December 28, 1990.

Abstract

The antiumor antibiotic adriamycin is presently considered to be a very effctive and useful chemotherapeutic agent in the treatment of many human tumors. Cardiotoxicity of adriamycin limits its clinical use. A number of hypotheses have been proposed to explain the mechanism of cardiotox- icity with adriamycin, but none has yet been demonstrated. The effects of adriamycin on twitch force and membrane potential in an isolated guinea-pig papillary muscle were studied. The results obtained as follows. 1) Adriamycin produced a positive inotropic effects in isolated beating papillary muscle. 2) Adriamycin induced hyperpolarization in diastolic membrane potential in papillary muscle. 3) Despite of the pretreatment of 10~5M propranolol, the positive inotropic effects and hyperpolar- ization in diastolic membrane potential caused by adriamycin were not abolished. From avove results, it was suggested that the mechanism of the positive inotropic effect and hyperpolarization in diastolic membrane potential caused by adriamycin does not involve 0- adrenergic stimulation in isolated guinea-pig papillary muscle.

Keywords :Adriamycin;Cardiotoxicity;Contractillity;Membrane potential;Papillary muscle