Pre-Treatment Effect of Voluntary Physical Activity on Cardiac Damage due to the Induction of Cumulative Doses of Doxorubicin in Aging Model Rats: Histopathological Examination of Heart Tissue

Reducing the effects of anthracyclines-induced cardiac toxicity is an effective strategy for more survival of cancer patients. This study aimed at investigating the pre-treatment effect of voluntary physical activity on cardiac damage due to the induction of cumulative doses of doxorubicin in aging model rats. 24 male Wistar rats (12 weeks old) were randomly divided into 3 groups: saline (S), doxorubicin (D), and voluntary physical activity (DWR). Ageing was induced by daily injection of D-galactose (100 mg/kg) for 9 weeks. 6 weeks of voluntary physical activity was performed on a wheel running. In the last 15 days of physical activity and D-galactose injection, doxorubicin with a cumulative dose of 15 mg/kg (or 1 mg/day) was injected. 48 hours after the end of physical activity and doxorubicin injection, the animals were euthanized and their left ventricles were severed for histological evaluation. The results showed that injection of doxorubicin insignificantly increased the apoptotic index and the ratio of heart weight to body weight while significantly decreased the ratio of fiber to the interstitial space (P