Figure 4

Tumor morphology in wild type (A) and AT ₂ -KO mice (B) was studied after hematoxylin and eosin staining. Tumor vessel density in wild-type (C) and AT₂-KO mouse tumors (D) was studied after endothelial cell staining using vascular endothelial cell-specific anti-von Willebrand factor antibodies. Average tumor vasculature numbers in AT2-KO mouse tumors (8.3 ± 0.1/field) were significantly higher than in wild type tumors (2.1 ± 0.5/field, p < 0.05). VEGF expression in wild-type (E) and AT₂-KO mouse tumors (F) was also studied after VEGF immunostaining using anti-VEGF antibodies. The original magnification of panels A and B is 200 × and panels C, D, E, and F is 400 ×.