L-carnitine attenuates doxorubicin-induced lipid peroxidation in rats

Doxorubicin (DOX) was administered intraperitoneally to rats in six equal, 2.5 mg/kg doses over a 2-week period with or without L-carnitine. Injury wa s monitored by echocardiography, release of myosin light chain-1 (MLC-1), a nd by measurement of aldehydic lipid peroxidation products. General observa tion revealed that DOX alone caused more ascites than DOX plus L-carnitine. Animals sacrificed 2 h after the sixth dose had significantly higher aldeh yde concentrations than 2 h after a single dose of DOX. Aldehydes in plasma and heart remained elevated for 3 weeks after the final dose of DOX, where as L-carnitine prevented or attenuated the DOX-induced increases in lipid p eroxidation. The increase in MLC-1 2 h after the sixth dose of DOX was grea ter than after a single dose, suggesting cumulative damage. Echocardiograph y did not detect either early injury or the protective effects of L-carniti ne. These data indicate that lipid peroxidation following DOX occurs early, and parallels the cumulative characteristics of DOX-induced cardiotoxicity . The protective effects of L-carnitine may be due to improved cardiac ener gy metabolism and reduced lipid peroxidation. (C) 1999 Elsevier Science Inc .