DELAYED DOXORUBICIN CARDIOMYOPATHY IN THE RAT - POSSIBLE ROLE OF REDUCED FOOD-INTAKE

The development of delayed doxorubicin cardiomyopathy in the rat is ac companied by profound anorexia, dramatically reducing the caloric inta ke. To assess the contribution of a restriction in food to the alterat ions in cardiac function, animals treated with doxorubicin were compar ed with a group of pair-fed control animals and with a second group of controls with unrestricted access to food. Prolongation of the Qalpha T interval of the electrocardiogram developed in rats treated with dox orubicin, but not in pair-fed controls. Myofibrillar ATPase activity a nd the contractile strength of isolated papillary muscles were depress ed in rats treated with doxorubicin, but not in pair-fed rats. The red uction in ventricular weight was proportional to the reduction in the body weight in pair-fed rats, whereas a higher ratio of ventricular to body weight was observed in rats treated with doxorubicin. These resu lts indicate that the alterations in cardiac function observed in dela yed doxorubicin cardiomyopathy are not due to a reduction in the intak e of food.