Figure 2. KO mice showed enhanced arteriogenesis and angiogenesis in vivo.

(A) KO mice showed augmented recovery of limb perfusion compared with WT mice. Blood flow of ischemic and nonischemic limbs were measured in gastronomic muscle at before surgery and 30 minutes, 3 days, 2 weeks, and 4 weeks after surgery. Data (mean ± SEM) are presented as the ratio of perfusion unit from nonischemic leg to ischemic leg. *P < 0.05. (B and C) Angiographic evidence for enhanced arteriogenesis in KO mice. Arterial phase angiograms from WT and KO mice after 4 weeks of ischemia (B) were determined by quantitative angiography (C). Data are mean values from 2 angiograms. *P < 0.05. (D–F) Enhanced angiogenesis in KO mice. Capillary density and pericyte recruitment were immunostained with CD31 (an EC marker). Representative sections from nonischemic and ischemic groups of WT and KO mice on day 28 after ischemia are shown in D. Quantification of capillary density (number/mm² muscle area) and ratio of CD31/myocyte are shown in E and F. Data are mean ± SEM from 10 fields per section (3 sections/mouse; n = 4 for each strain). *P < 0.05.