Figure 3.

Effects of STI571 on the degree of muscularization (A–C), medial wall thickness of small pulmonary arteries (D–F), and PDGF-B expression (G–I). A, D, and G: Day 0. B, E, and H: Day 42. C, F, and I: Day 42 treated with 50 mg/kg/d STI571. (A–C) The degree of muscularization is demonstrated by von Willebrand (brown) and α–smooth muscle actin (purple) staining for identifying endothelium and vascular SMCs, respectively. (D–F) Changes in medial wall thickness in pulmonary arteries are demonstrated. (G–I) PDGF-B staining is demonstrated in the medial layer of small pulmonary arteries. Scale bars: 20 μm. The arrows indicate pulmonary arteries.