Figure 3.

CCR2 deficiency affects muscularization of pulmonary arteries. (A) Fluorescent α-smooth muscle actin (α-SMA) staining of normoxic and hypoxic lungs of WT and Ccr2^−/− mice. Ccr2^−/− mice show increased muscularization of vessels (white arrows). Original magnification, 50×. (B) Quantification of muscularized vessels in WT and Ccr2^−/− mice. Under normoxic conditions, Ccr2^−/− mice have a higher proportion of vessel muscularization; with hypoxia, Ccr2^−/− mice have a significantly increased percentage of muscularized pulmonary artery compared with WT mice (n = 5 to 7 mice per group). *P < 0.05; **P < 0.01; ***P < 0.001.