Figure 4: Different sections of rat�s hearts with Toluidine blue stain (x1000): A: Doxorubicin untreated group showed marked loss of myofibrils and vacuolization of cytoplasm. B: Doxorubicin-Carvedilol treated group showed partial preservation of myofibrils and moderate cytoplasmic vacuolization.C: Doxorubicin- Nebivolol treated group showed best preservation of myofibrils and minimal vacuolization of cytoplasm.