Fig. 4

Immunohistochemistry staining of vascular endothelial growth factor A (VEGF) and CD31 in synovial membranes collected from collagen-induced arthritis (CIA) mice. a VEGF (red arrows) is expressed in the synovial membrane of mice with CIA. b CD31 staining (red arrows), i.e., the number of microvessels in untreated control CIA mice. c CD31 staining (red arrows), i.e., the number of microvessels in CI (50 mg/kg once daily orally for 14 days) treated CIA mice. d Significantly reduced CD31 staining, i.e., the number of microvessels in CI-treated mice in comparison to the CI untreated control group (data are expressed as mean ± SEM; *P < 0.05 versus control, Student’s t test). Scale bar = 100 μm. The figure is representative of 12 (6 = untreated control mice; 6 = CI-treated control mice) separate experiments undertaken in different animals with similar results