Histologic and immunohistochemical analysis of Matrigel implants. Representative hematoxylin and eosin–stained sections of Matrigel containing VEGF (A) or VEGF plus SnPP (B) implanted in mice and excised 6 days after injection. A dense inflammatory infiltrate around vessels was observed in plugs containing VEGF plus SnPP when compared with VEGF alone (original magnification × 160). (C-D) Double immunofluorescence staining for VWF (C) and MPO (D) showing the presence of leukocytes around vessels in plugs with VEGF plus SnPP (original magnification × 250). (E-F) Representative hematoxylin and eosin–stained sections of Matrigel containing LPS (E) or LPS in the presence of CoPP, which prevented leukocyte-dependent angiogenesis (F) (original magnification × 160).