Impaired physiological responses to chronic hypoxia in mice partially deficient for hypoxia-inducible factor 1α
J. Clin. Invest. Aimee Y. Yu, et al. 103:691 doi:10.1172/JCI5912 [Go to this article.]

Figure 6
Morphometric analysis of pulmonary vasculature in chronically hypoxic mice. (a) Neomuscularization of pulmonary arterioles. Lung sections from Hif1a^+/+ (open bars) and Hif1a^+/– (closed bars) mice exposed to 10% _O for 3 weeks were scored for nonmuscularized (N), partially muscularized (P), or completely muscularized (C) arterioles with an external diameter of ≤100 μm. For each genotype, >400 vessels were analyzed in lung sections from three to four mice to generate the mean data shown. χ² analysis revealed a significant difference between genotypes (P = 0.00001). (b) Quantitative analysis of medial thickening. Percent wall thickness (% WT) was calculated for completely muscularized arterioles, based on analysis of area or diameter, according to the following formulae: % WT = ([area_ext – area_int] / area_ext) × 100; and % WT = ([diameter_ext – diameter_int] / diameter_ext) × 100. Dimensions were demarcated by the external (ext) and internal (int) elastic laminae. For each genotype, >100 vessels were analyzed in multiple lung sections from three to four mice. Mean values are shown (SD ≤ 0.6% for each). *P < 0.001 (Student's t test).