Fig. 6

Efficacy of long-term tadalafil treatment from day 14 to 42 after MCT injection in Bmpr2 mutant (+/44insG) and wild-type rats. A Survival outcomes of wild-type (WT) and Bmpr2 mutation (+/44insG) rats after monocrotaline (MCT) injection treated with long-term tadalafil (10 mg/kg/day) from day 14 to 42 (n = 37, WT and +/44insG). B The percentage of body weight change from initiation of experiment in WT (open circle) and +/44insG (closed circle) rats. C mPAP (n = 9, WT and +/44insG) and D RV/(LV + S) (n = 12, WT and +/44insG). E The quantification of percentage muscularization of distal pulmonary arteries (PAs) (n = 12, WT and +/44insG) and F the quantification of the number of distal PAs per 100 alveoli (n = 12, WT and +/44insG). G and H Representative images of barium filled vessels in diameters 15–50 μm in WT and +/44insG rats respectively. Scale bar: 10 μm. I The quantification of the percentage of medial wall thickness (%MWT) in vessels sized 15–50 μm in WT and +/44insG rats (n = 12, WT and +/44insG). J–M Representative images of right ventricle myocardial tissue by Masson's trichrome stain and N the quantification of right ventricle myocardial fibrosis in WT and +/44insG at 6 weeks after MCT injection (n = 8, WT and +/44insG). Scale bar: 50 μm. The numbers in parentheses represent the numbers of rats examined. For panel A, data are presented by Kaplan- Meier survival plot and Log-rank (Mantel-Cox) test was used; for panel B data are presented as scatter plots indicating all data points; for panels C–F, I and N, the data are presented as means ± SEM; unpaired t-test for was used for analysis; *p < 0.05, **p < 0.01, ***p < 0.001. WT = wild-type; +/44insG = rats with bone morphogenetic protein receptor type 2 mutation; MCT = monocrotaline; mPAP = mean pulmonary artery pressure; RV/(LV + S) = weight ratio of right ventricle/left ventricle plus septum; PAs = pulmonary arteries; %MWT = the percentage of medial wall thickness; RV = right ventricle