Figure 3.

Vessel ingrowth into the apical thrombus precedes cardiomyocyte migration after resection. Histologic analysis of sagittal heart sections demonstrated that vessels enter the apical thrombus early and mature over time. Endothelial cells always extended deeper into the thrombus than cardiomyocytes. A, Migrating endothelial cells in the apical thrombus, visualized by vascular endothelial cadherin staining. Capillary formation was first noted in the apical thrombus at 2 days postresection. B, An artery characterized by a smooth muscle layer in the apical thrombus at 5 days postresection. Arteries in the apical thrombus were first noted at 5 days postresection, but did not consistently appear until 7 days postresection. C, A large ingrowing artery within the apical thrombus at 7 days postresection. Arteries were found within apical thrombus of all hearts treated with apical resection at 7 days postresection and onward. D, A lectin-perfused vessel in the apical thrombus at 5 days postresection. This suggests that ingrowing vessels become functional by 5 days postresection. Green =14; α-actinin, red =14; vascular endothelial cadherin, red, magenta=14; smooth muscle actin, blue =14; DAPI, white =14;lectin. All scale bars represent 25 μm. SMA, Smooth muscle actin; VE, vascular endothelial; DAPI, 4′,6-diamidino-2-phenylindole.