Figure 2.

(A) Histological changes in the lungs. Representative images of Verhoeff–van Gieson-stained lungs show a severe remodeling of pulmonary arteries. Scale bars: 100 μm. (B) Quantitative analysis of pulmonary artery remodeling. The vascular occlusion score was significantly increased in both male and female HZ and HM groups compared with control (mean ± SEM, n = 5–7, *P < 0.05 versus control, ANOVA; for each animal, a random 10 vessels were averaged). (C) Representative three-dimensional micro–computed tomography images of the pulmonary vasculature in WT and HM female rats. Three different views of each lung are shown. (D) Representative microangiogram images show the vascular morphology of the right middle lobe of female WT and HM rats (scale bars: 5 mm) and the morphology of small pulmonary arteries (scale bars: 1 mm). Double-sided arrows show that HM rats have an increase in the area of low vascular density. This decrease in the complexity and number of the small pulmonary arteries could be due to a combination of pulmonary arterial hypertension–associated microvascular rarefaction and vasoobliterative disease. The arrowheads point to multiple occlusions of the small pulmonary arteries that appear as a break in pulmonary artery integrity or as an extraslim section.