Myocardial cation transport
作者:
Melissa Doohan,
Helge Rasmussen,
期刊:
Journal of Hypertension
(OVID Available online 1993)
卷期:
Volume 11,
issue 7
页码: 683-691
ISSN:0263-6352
年代: 1993
出版商: OVID
关键词: Action potential;adenosine triphosphatase;cardiac glycosides;cardiac hypertrophy;cardiomyopathy;congestive heart failure;cation;cell membrane;hydrogen ion concentration;myocardial contraction;sarcoplasmic reticulum
数据来源: OVID
摘要:
Background:Intracellular cations regulate a variety of functions in myocytes, and abnormalities in ionic homeostatic control have been implicated in several cardiac disease processes. These include cardiac hypertrophy, some of the cardiomyopathies and reperfusion injury following myocardial ischaemia.Topics under review:Current understanding of the sarcolemmal transport mechanisms which generate transmembrane electrochemical gradients for Ca2 +, H+and K+is reviewed. Both active, ATP-dependent membrane ion transport and secondary active transport are described. The importance of the sarcolemmal Na+—K+pump in maintaining transmembrane gradients for Na+and K+is emphasized, and we describe how the electrochemical energy stored in the Na+gradient generated by the pump is utilized by ion-exchange processes in which a tightly coupled exchange of extracellular Na+for intracellular Ca2+or H+occurs. We also describe cotransport processes in which coupled obligatory transport of Na+, K+and Cl−occurs in the same direction. Physiological and pharmacological properties of sarcolemmal ion transport mechanisms are reviewed and reference is given to possible clinical implications.
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