AMD3100 prevented severe pulmonary arterial hypertension (PAH) in the SU5416/chronic hypoxia (SuHx) model.

(A) Representative von Willebrand Factor (vWF) immunohistochemistry indicates the occlusion of pulmonary arteries (arrows). These images demonstrate that treatment with the CXC chemokine receptor 4 inhibitor AMD3100 only partially prevented the obliteration of pulmonary arteries. Counterstaining: Mayer’s Hematoxylin. Magnification: 100×. Scale bar: 100 µm. (B) Reduced right ventricular systolic pressure (RVSP) and (C) decreased right ventricle (RV)/(left ventricle [LV]+Septum) ratio. (D) Reduced pulmonary arterial muscularization (external diameter [ED] <100 µm) was detected after AMD3100 treatment. (E-F) The degree of obliteration of pulmonary arteries in AMD3100-treated SuHx animals was partially reduced for small (E) (25 µmP<0.05, ** P<0.01, *** P<0.0001.