Figure 3

Hypoxia-increased pulmonary vascular muscularization. After exposure in hypoxia for 42 d, lung was fixed and stained with anti-α-SMA antibody. Vascular muscularization was evaluated by a blind method. The percentages of nonmuscularized (NM, □), partial muscularized (PM, ), or completely muscularized (CM, ■) vessels at different subgroups with different external diameter (ED <30 µm, 30–50 µm, and >50 µm) were calculated (A). The muscularization index (MI) of every animal was also calculated by the formula: MI = (number of CM × 2 + number of PM)/total observed vascular number (B). (Data presented as average ± SD. *P < 0.05 versus normoxia; **P < 0.01 versus normoxia.) N, normoxia; H, hypoxia.