Hypoxic regulation of ion channels and transporters in pulmonary vascular smooth muscle.

Exposure to prolonged alveolar hypoxia, as occurs with many chronic lung diseases or residence at high altitude, results in the development of pulmonary hypertension, significantly worsening patient prognosis. While the structural and functional changes that occur in the pulmonary vasculature in response to chronic hypoxia have been well characterized, less is known regarding the cellular mechanisms underlying this process. The use of animals models of hypoxic pulmonary hypertension have provided important insights into the changes that occur in the pulmonary vascular smooth muscle cells and some of the mediators involved. In this chapter, the effect of chronic hypoxia on various pulmonary arterial smooth muscle cell ion channels and transporters, and the role of the transcription factor, hypoxia-inducible factor 1, in regulating these changes, will be discussed.