Fig. 3. Histological analysis of wild-type and transgenic hearts. Heart sections from wild-type (A,D), MHC/Ncad (B,E), and MHC/Ecad (C,F,G,H) indicated that both transgenes can elicit a hypertrophic response; however, the MHC/Ecad was consistently more severe. The MHC/Ncad heart (B) was enlarged with dilated left ventricle and thin ventricular wall. In comparison, both ventricles and atria were severely dilated in the MHC/Ecad heart (C). Enlarged myocytes with hyperchromatic nuclei were observed in both transgenic hearts (E,F). Many `binucleated' myocytes were seen in the MHC/Ecad heart (F, arrows) in comparison to MHC/Ncad (E). At 2 months of age, left atrial thrombosis (arrow) was observed in the MHC/Ecad heart (G). Alizarin Red staining showed regions of calcification (arrows) in the ventricle and pericardium of the MHC/Ecad heart (H). Thrombosis and calcification were observed in the MHC/Ncad hearts (not shown). Bars, 2.5 mm (A,B,C,G); 50 µm (D,E,F); 500 µm (H).

Return to article