Disorders Ca2+ Homeostasis in Rat Cardiac Mitochondria Affected by Adriamycin

To determine the mechanism of adriamycin (ADR) induced cardiotoxicity, the effects of ADR on the Ca2+ uptake and release of cardiac mitochondria were investigated. Male Wistar rats were injected intraperitoneally with 4 mg/kg body weight of ADR for 6 consequtive days, and mitochondria were isolated from heart muscle. Ca2+ uptake and release of cardiac mitochondria were measured spectrophotometrically using a metallochromic dye antipyrylazo III. The total calcium content was determined by atomic absorption. ADR administration resulted in reductions of the Ca2+ uptake velocity, Na+-Ca2+ exchange velocity and the calcium content in cardiac mitochondria. The data reported here is useful for understanding the pharmacological effect of adriamycin to unfavourable side-effect, cardiotoxicity.