Lactate transport in heart in relation to myocardial ischemia

Halestrap, Andrew P. and Wang, Xuemin and Poole, Robert C. and Jackson, Vicky N. and Price, Nigel T. (1997) Lactate transport in heart in relation to myocardial ischemia. American Journal of Cardiology, 80 (3). 17A-25A. ISSN 0002-9149 . (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1016/S0002-9149(97)00454-2

Abstract

In this article, the importance of lactic acid transport into and out of heart cells is described and the properties of the monocarboxylate transporters (MCTs) responsible a re presented. These are monocarboxylate/proton symporters with a broad substrate specificity that includes L-lactate, pyruvate, and the ketone bodies acetate, acetoacetate, and beta-hydroxybutyrate. Although it is unlikely that lactic acid transport constrains heart metabolism under most conditions, it may do so during severe hypoxia or ischemia. The transporter plays a critical role in maintaining intracellular pH because it removes the protons that are produced stoichiometrically with lactate during glycolysis. The kinetics and substrate and inhibitor specificities of the transport process have been determined in cell suspensions using a radiotracer technique and in single cells using a fluorescent measurement of the decrease in intracellular pH that accompanies transport. The results of these experiments suggest the presence of 2 different transporter isoforms in heart cells, at least one of which is different from the cloned MCT1 and MCT2. Immunofluorescence microscopy shows that MCT1 expression is restricted to the intercalated disk region, yet the rate of lactate transport in this region is slower than in the center of the cell, where there is no MCT1. New cDNA sequences with strong homology to MCT1 have been found in human cDNA libraries and Northern blots show that the corresponding mRNA is expressed in rat heart. Expressions of these new MCT isoforms have yet to be demonstrated and their properties and cellular distribution defined.

Item Type: Article
Additional information: Document Type: Proceedings Paper Conference Information: Symposium on Autocrine and Paracrine Signaling Between Contracting Myocardium and Coronary Endothelium During Ischemia - Effect of Insulin Resistance Baden Baden, Germany, Sep 28-29, 1996 Max Grundig Fdn
Subjects: R Medicine
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: M.A. Ziai
Date Deposited: 16 Sep 2009 02:27
Last Modified: 14 Apr 2014 14:04
Resource URI: http://kar.kent.ac.uk/id/eprint/18091 (The current URI for this page, for reference purposes)
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