Ion channels in pulmonary arterial hypertension☆☆☆
Abstract
Pulmonary arterial hypertension (PAH) is a hemodynamic abnormality that ultimately results in mortality due to right heart failure. Although the clinical manifestations of primary and secondary PAH are diverse, medial hypertrophy and arterial vasoconstriction are key components in the vascular remodeling leading to PAH. Abnormalities in the homeostasis of intracellular Ca2+, transmembrane flux of ions, and membrane potential may play significant roles in the processes leading to pulmonary vascular remodeling. Decreased activity of K+ channels causes membrane depolarization, leading to Ca2+ influx. The elevated cytoplasmic Ca2+ is a major trigger for pulmonary vasoconstriction and an important stimulus for vascular smooth muscle proliferation. Dysfunctional K+ channels have also been linked to inhibition of apoptosis and contribute further to the medial hypertrophy. This review focuses on the relative role of K+ and Ca2+ ions and channels in human pulmonary artery smooth muscle cells in the development of PAH. Copyright 2002, Elsevier Science (USA). All rights reserved.
Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California School of Medicine, San Diego, CA.
☆ Supported in part by grants from the National Institutes of Health (HL 54043, HL 64945, HL 66012, and HL 69758). and the American Heart Association.
☆☆ Address reprint rquests to Jason X.-J. Yuan, MD, PhD, Division of Pulmonary and Critical Care Medicine, UCSD Medical Center, 200 W. Arbor Dr, San Diego, CA 92103-8382.
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