Hypoxic pulmonary vasoconstriction

Abstract

It has been well known that the mean pulmonary arterial pressure rises proportionally to the degree to which the oxygen saturation of the arterial blood is lowered. Such evidence that hypoxia causes pulmonary vasoconstriction has well been confirmed by many investigators, however, precisely how these events are brought about remains unclear. After defining the effects of hypoxic pulmonary vasoconstriction (HPV) on ventilation-perfusion inequality referring to in terms of its effects on arterial oxygenation, the author tried to summarize from the recent papers on HPV the problems on the site of HPV, on the many factors affecting HPV (Pv̄(O2), repeated hypoxic challenges, CO2 and pH, anesthetics, Ca-blockers, prostaglandins, aspirin, histamine, catecholamines, and angiotensin-II) and finally on the triggering mechanism involved in the pulmonary artery pressor response to hypoxia.