Establishing endothelial function in the immature pulmonary vasculature, normal and hypertensive

Endothelial dysfunction is characteristic of all vascular disorders and is the focus of considerable clinical and basic research activity. It is possible that having insight into the maturation of normal endothelial function during early development, and understanding the initial derangements caused by abnormalities in pressure and flow might provide clues about how best to correct and reverse endothelial dysfunction in disease (Figure 1). This presentation will address endothelial function in the pulmonary circulation, but many of the basic mechanisms involved in the pathogenesis of vascular disease are common to both pulmonary and systemic circulations. This chapter will start by summarising our present understanding of pulmonary endothelial dysfunction in children, followed by an account of normal pulmonary endothelial maturation and the influence of pulmonary hypertension in experimental animal models, in an attempt to gain insight into the pathogenesis of the human disease process.