Cardiotoxic consequences of ionizing radiation and anthracyclines

The mechanisms of the toxic side effects of radiation and anthracyclines are generally based on free radical reactions. Target molecules for free radicals are not only DNA and proteins, but also membrane structures abundant in phospholipids. Cardiomyocyte membrane lipid peroxidation may consequently lead to structural and functional damage. The dynamics of oxidative injury result from the oxidative stress status on the one hand and lowered antioxidant defense on the other. Heart muscle is especially vulnerable to the oxidative activity of free radicals generated by both radiation and cytostatics because of its low antioxidant defense. The toxic effects of radiation and cytostatics are a serious clinical problem connected with the physiologically or pathologically reduced antioxidant defense of normal tissues involved in the therapy. The additive, even synergistic, effects of the polychemotherapy usually used before, during, and after radiation often disguise postradiation effects on cardiac muscle.