A photomicrograph of the myocardium of a rat given DOX ( 20 mg/kg,i.p.) a :showing areas of myocytolysis(m). H&E × 400. b: showing congestion of blood vessels (arrows). H&E × 400. c: showing myocytes with cytoplasmic vacuolization (V) or fragmentation (F). Some nuclei were pyknotic (thin arrow) while others revealed chromatin margination (thick arrow). H&E × 400. d: showing hyalinization of the muscle fiber (thick arrow). Notice the congested blood vessel (thin arrow). H&E × 400. e: showing chromatin margination of some nuclei (black arrows)while others were pyknotic (white arrows). Areas empty of muscle fibers around the pyknotic nuclei were evident (thick arrow). H&E × 400.