Fig. 4

Main histopathological features of intra-acinar pulmonary arteriopathy induced by MCT. Histological sections stained with Movat (a–d). The vessel was decorated with anti-vascular endothelial growth factor antibody (VEGF) (e–h), revealing the endothelial expression (black arrow) to be composed of VEGF-positive cells. Intra-acinar artery: normal wall thickening and endothelial VEGF expression (arrows) in CTRL-SAL (a, e) and CTRL-MSC (b, f) respectively. Intra-acinar artery: hypertrophy and hyperplasia of smooth muscle fibers (c) and increased VEGF expression (g) in an MCT-SAL animal. Intra-acinar artery: attenuation of muscle cell hyperplasia (d) and VEGF expression (h) in an MCT-MSC animal. Lines represent medians, and whiskers are the interquartile range of seven animals in each group. Comparisons by Student’s t test followed by Bonferroni’s corrections for three comparisons (*p < 0.0167). CTRL control, MCT monocrotaline, SAL saline