Figure 2. Endothelial catalase overexpression impairs collateral remodeling and stabilization of vessels undergoing neovascularization.

A, collateral remodelling after hindlimb ischemia was analyzed in the same anatomical arteries localized at semimembranosus muscles in the upper limbs between wild-type (WT) and Tie2-driven catalase transgenic (Cat-Tg) mice. The luminal diameter and wall area are calculated from the measurements of luminal and perivascular tracing. Arrows indicate collateral wall. B, ischemic gastrocnemius muscles were analyzed for the morphology of vessels at day 3 with immunostaining for an endothelial-marker, CD31 (green). Nuclei were visualized by 4′,6-diamidino-2-phenylindole (DAPI) (blue). Magnified images show that morphologically disorganized vessels with varying size, enlarged lumen and irregular shape are often seen in Cat-Tg mice. C, capillary densities in the same region as B were analyzed by CD31 staining at day 7. Bars indicate 20 μm in A, and 50 μm in B and C. All data shown are mean+SE (n = 3–4 mice per group, *p<0.05 and **p<0.01).