Figure 4.

(A) Right common carotid artery diameter at 4 weeks after flow augmentation or sham surgery. Macrophage depletion reduced flow-induced outward vascular remodeling. Between the macrophage intact groups, flow augmentation by left common carotid artery ligation increased the luminal diameter of the right common carotid artery (Group 1 versus Group 3). In the macrophage-depleted group, less outward vascular remodeling occurred in response to flow augmentation. (Group 3 versus Group 4: 1.10±0.06 versus 0.95±0.03 mm, P<0.05). (B) Shear stress levels common carotid artery diameter at 4 weeks after flow augmentation or sham surgery. Shear stress levels were presented as % control using the baseline values as control. Shear stress levels in flow-augmented common carotid artery in macrophage-depleted mice were significantly higher than other three groups of animals, reflecting that reduced outward vascular remodeling in macrophage-depleted mice could not normalize shear stress levels that were increased by flow augmentation. (Mean±s.d.; ^*P<0.05, compared with the sham groups; ^#P±0.05, compared with Group 3; n=6 in each group.)