Fig. 8

Electron micrograph of a section of cardiac muscle from a control group showing parallel arrays of myofilaments comprised of regular sarcomere (Sm) with evident Z line (Z) and the M line (ml) bisect the H zone, A (dark band), I (light band). Notice the mitochondria (M) with regular cristae arranged between the myofibrils. b DMBA group demonstrating poorly organized myofibrils with disrupted Z line, areas of myofilaments degeneration (asterisk), interruption and fragmentation of myofibrils. The sarcoplasmic reticulum enveloping the sarcomere (Sm) units shows large distensions. Notice the disorganization of the mitochondria (M) and abnormal aggregation of some swollen mitochondria with disrupted cristae. c (DMBA + Art) group showing cardiac muscle with poorly organized myofibrils, disrupted Z line, areas of myofilaments degeneration (star). Notice the disorganized mitochondria (M), where some of them are swollen (arrow). d (DMBA + Ech) group demonstrating cardiac muscle with nearly fine organized myofibrils, clear Z line (Z), degeneration in some cardiomyocytes (arrow) and degenerated mitochondria (M). e (Art + DMBA) group demonstrating cardiac muscle with nearly fine organized myofibrils, clear Z line (Z), disorganized intercalated disk (arrow), little areas of degenerated myofilaments (star). Notice the mitochondria (M) with regular cristae. f (Ech + DMBA) group demonstrating cardiac muscle with well-organized myofibrils and clear Z line (Z). Notice the mitochondria (M) with good cristae and normal distribution of intercalated disk (white arrows) (Scale bar = 2 μm)