Representative histology of the adult heart.

(A) Cross section at the level of the pars muscularis of the interventricular septum. Tg hearts were enlarged with biventricular dilatation and hypertrophy of the free walls. (Hematoxylin-eosin stain; magnification ×3.5, scale 3 mm.) (B) Prominent hyperemia of the capillaries packed with erythrocytes in the tg heart. (Trichrome; magnification ×106, scale 200 μm.) (C) Transmission electron micrograph showing marked intracellular edema in cardiomyocytes of the tg heart (arrows, lower right part). (Magnification ×8300, scale 5 μm.)