A and B. Representative record of right ventricular pressure (RVP, A) and summarized data (means±SE) showing the peak value of right ventricular systolic pressure (RVSP, B) in normal control rats (Norm, n=6) and MCT-injected rats (MCT, n=6) that are treated with vehicle (−NPS) or NPS 2143 (+NPS, 4.5 mg/kg once a day). C. Averaged Fulton index [RV/(LV+S) ratio, means±SE] showing that RV hypertrophy is significantly inhibited in MCT-rats treated with NPS. *P<0.05 vs. MCT along. D and E. Representative H&E images of small pulmonary arteries (D) and summarized data of the medial thickness of pulmonary arteries with a diameter (Ø) less than 50 μm, between 50 and 100 μm and greater than 100 μm (E) in normal control rats (Norm, n=6) and MCT-injected rats (MCT, n=6) that are treated with vehicle or NPS 2143. *P<0.05 vs. MCT-treated rats (red bars).