Hemodynamic and pulmonary small arterial remodeling index in the Sham, PAH, PAH + Sildenafil and PAH + Sildenafil + LDN-193189 groups. A: mPAP in different groups, (n=6); B: RVSP in the Sham, PAH, PAH + Sildenafil and PAH + Sildenafil + LDN-193189 groups, (n=6); C: Right ventricular hypertrophy indexed by the ratio of wet weight of the right ventricle to the left ventricular wall plus septum [Rv/(Lv + S)] in the Sham, PAH, PAH + Sildenafil and PAH + Sildenafil + LDN-193189 groups (n=6); D, E: Pulmonary small arterial remodeling indexed by the ratio of muscular arterials and wall thickness/radius in the Sham, PAH, PAH + Sildenafil and PAH + Sildenafil + LDN-193189 groups (n=6).