Fig. 3

Selective complement C3 inhibitor CP40-KK ameliorates indices of PAH in an established rat PAH model A Schematic diagram of animal experiment procedure. PAH was induced by MCT at the dose of 40 mg/kg at day 1. Treatment with CP40-KK 2 mg/kg/day by subcutaneous injection at day 15 to day 28 continuously. B–D Right ventricular systolic pressure (RVSP), right ventricular hypertrophy indexes (RV/LV + S) and RV/body weight (BW) were decreased by CP40-KK in MCT-induced PAH rats (n = 6 per group). E,G–H Representative HE staining images of rat lungs from all four groups E and graphs reflecting the percentage of medial wall thickness WT% and vessel wall area WA% (G,H; n = 6 per group). E,I,K Pulmonary vascular remodeling was ameliorated by CP40-KK in MCT-induced PAH rats. E Representative immunohistochemical staining images of α-SMA from all four groups. I,K Representative western blots and quantification of PCNA protein levels in lung homogenates (n = 6 per group). F,J Representative Western blots and quantification of C3a protein levels in the rat plasma (n = 6 per group). Scale bar: 20 μm (E,F); MCT: monocrotaline, RV: right ventricle, LV: left ventricle, S: septum; mean ± SEM; Multiple comparisons made by one-way ANOVA; *P < 0.05, **P < 0.01