Hypoxia in lung vascular biology and disease.

Abstract

See reviews in the series by Weissmann et al. [3] (pages 620–629), Weir and Olschewski [4] (pages 630–641), and Fandrey et al. [6] (pages 642–651) in this issue and by Ghohani et al. [7] and Maggiorini [8] in next month's issue. With the evolution of photosynthesis, organisms had to cope with a dramatic environmental change: the presence of oxygen. Despite the initial toxicity of this gas, the presence of molecular oxygen offered a more effective energy metabolism. As a result, animals and humans require oxygen to survive, and a shortage of oxygen, hypoxia , can evoke life-threatening conditions. To maintain an optimal energy supply for the body, the lung is the first-line organ functioning as an interface between the body and the environment. This organ is the focus of an overview of the various aspects of “ Hypoxia in the Pulmonary Circulation ” in this Review Focus Series . The lung structure is designed to achieve a very rapid and effective gas exchange. This is accomplished by two components, a large gas exchange surface and an extremely thin diffusion barrier between the alveolar gas and the blood [1]. The large capillary surface and the fragile diffusion barrier require a low blood pressure in the lung compared to the systemic circulation. In fact, pulmonary arterial blood pressure ranges <20 mmHg in healthy humans to prevent the risk of lung oedema and bleeding. In addition …