Effect of adriamycin on the activity of the succinate dehydrogenase-coenzyme Q10 reductase of the rabbit myocardium.

Rabbits were injected with adriamycin 3 days/week/7 weeks. Heart tissues of treated rabbits showed myocardial degeneration, but the tissues of controls were normal. The deficiency in the activity of the succinate dehydrogenase-coenzyme Q10 reductase in the heart tissues of the rabbits treated with adriamycin was higher (0.001 less than P less than 0.01) than that for control tissues. These data indicate a correlation of at least a part of the cardiotoxicity of adriamycin in cancer patients to inhibition of CoQ10-enzymes, since coenzyme Q10 is indispensable to bioenergetics in the myocardium of both humans and rabbit.