Remodeling of Potassium Channels in Cardiac Hypertrophy

B.I. Jugdutt and N.S. Dhalla (eds.), Cardiac Remodeling: Molecular Mechanisms, Advances in Biochemistry in Health and Disease 5, DOI 10.1007/978-1-4614-5930-9_2, © Springer Science+Business Media New York 2013 Abstract The potassium channel is a major target of remodeling in cardiac hypertrophy. To maintain physiological cardiac function in the face of increased workloads, hypertrophied cardiac myocytes undergo downregulation of K + channels that results in a prolongation of action potential duration (APD) and upregulation of Ca 2+ entry channels. Increased intracellular calcium in cardiac hypertrophy activates calcineurin/nuclear factor of activated T cell pathway to permit remodeling of the K + channels, resulting in a positive feedback between the K + channel remodeling and alteration of Ca 2+ handling. Although the I to channel is the major target of the K + channel remodeling in hypertrophied cardiomyocytes, alteration of other K + channels and/or K + channel regulators plays an important role in the remodeling and arrhythmogenicity. In this chapter, we list types of K + channels and their mRNA that undergo remodeling in cardiac hypertrophy and discuss molecular mechanisms of the remodeling.