Fig. 6.
Dual ETA/ETB receptor blockade improves lung perfusion in Sugen/hypoxia rat model of PAH. (a) CT angiogram with image reconstruction of the lung after microfil perfusion. Vascularization was quantified in silico using Microview software in normoxic rats, 5 weeks after sugen injection, as well as 5 weeks after sugen injection + 2 weeks of treatment with vehicle and macitentan (n = 6/group). (b) Lectin perfusion (in green) and DAPI (in blue) were also used to visualize lung vascularization in lungs of normoxia (n = 4), PAH 5 weeks (n = 4), PAH 5 weeks +vehicle 2 weeks (n = 10), and PAH 5 weeks + maci (macitentan) 2 weeks (n = 10). The number of lectin-positive vessels was manually calculated in ten different fields per specimen. (c) CD31 immunostaining (in red; arrow) and DAPI (in blue) were used to assess lung microcirculation density of normoxia, PAH 5 weeks, PAH weeks + vehicle 2 weeks, and PAH 5 weeks + maci (macitentan) 2 weeks (n = 4–5/group). The number of CD31 positive vessels was manually calculated in ten different fields per specimen. *P < 0.05; ****P < 0.0001. Scale bars: 20 µm in (b); 50 µm in (c).