Expansion of the vasa vasorum in hypoxic pulmonary hypertension. Increase in the density of vasa vasorum (arrows) in proximal (a) and distal (b) vessels from hypoxic animals, compared with proximal (c) and distal (d) vessels from normoxic animals. Vasa (arrows) in hypoxic proximal and distal arteries express platelet endothelial cell adhesion molecule (PECAM)-1 (e and f, respectively). Quantitative morphometric analysis demonstrated that the volume density (Vv) of the vasa vasorum is signifi cantly greater in the adventitia and media of the pulmonary arteries of chronically hypoxic animals, at every level along the longitudinal axis of the pulmonary circulation than in the controls. Monocytes (CD11b) appear preferentially next to the vasa (eNOS+cells) in hypoxic vessels.
Additional keywords: vasa vasorum,elastic,morphometry,