Fig. 21.

Vascular changes in homografts of untreated recipients. A, portal tract of untreated canine hepatic homograft shown in Figure 20. Portal vein is surrounded by mononuclear cells, some of which can be seen in the vessel wall. Hepatic artery is unaffected. Hematoxylin-eosin; ×500. B, central vein, surrounded by mononuclear cells, from untreated canine homograft shown in Figures 9 and 10. Some cells are adhering to the endothelium and others are infiltrating the vein wall. Hematoxylin-eosin; ×500. C, focus of fibrinoid necrosis (arrows) in wall of a small branch of the hepatic artery in a canine liver 7 days after homotransplantation. Hematoxylin-eosin; ×500.