Relative distribution of three major lactate transporters in frozen human tissues and their localization in unfixed skeletal muscle
- 28 June 2002
- journal article
- research article
- Published by Wiley in Muscle & Nerve
- Vol. 26 (1) , 101-112
- https://doi.org/10.1002/mus.10168
Abstract
We have prepared affinity-purified rabbit polyclonal antibodies to the near-C-terminal peptides of human monocarboxylate transporters (MCTs) 1, 2, and 4 coupled to keyhole limpet hemocyanin. Each antiserum reacted only with its specific peptide antigen and gave a distinct molecular weight band (blocked by preincubation with antigen) after chemiluminescence reaction on Western blots from sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) of tissue membrane proteins. Densitometry showed distinctive expression patterns for each MCT in a panel of 15 frozen human tissues, with the distribution of MCT1 ≫L:MCT2>MCT4. Fluorescence microscopy of unfixed skeletal muscle using fluorescein-conjugated secondary antibody was correlated with reverse adenosine triphosphatase (ATPase) stained sequential sections to identify fiber-type localization. MCT1 expression was high in the sarcolemma of type 1 fibers, modest to low in type 2a fibers, and almost absent in type 2b fibers. In contrast, MCT4 expression was low to absent in the membrane of most type 1 fibers, but high in most 2a and in all 2b fibers, favoring the view that their high lactate levels during work may be channeled in part to neighboring type 1 (and perhaps 2a) fibers for oxidation, thereby delaying fatigue. MCT2 expression was limited to the sarcolemma of a type 1 fiber subset, which varied from <5 to 40%, depending on the specific muscle under study. Quantitative chemiluminescent densitometry of 10 muscle biopsies for their MCT2 and MCT4 content, each normalized to MCT1, confirmed the unique variation of MCT2 expression with biopsy site. The application of these antibodies should add to the understanding of motor unit physiology, and may contribute to the muscle-biopsy assessment of low-level denervation. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 101–112, 2002Keywords
This publication has 32 references indexed in Scilit:
- Protective effects of lactic acid on force production in rat skeletal muscleThe Journal of Physiology, 2001
- Characterisation of human monocarboxylate transporter 4 substantiates its role in lactic acid efflux from skeletal muscleThe Journal of Physiology, 2000
- Expression of the monocarboxylate transporter MCT2 by rat brain gliaGlia, 1998
- cDNA Cloning of the Human Monocarboxylate Transporter 1 and Chromosomal Localization of the SLC16A1 Locus to 1p13.2-p12Genomics, 1994
- Clinical assay of the human erythrocyte lactate transporterBiochemical Medicine and Metabolic Biology, 1988
- Clinical assay of the human erythrocyte lactate transporterBiochemical Medicine and Metabolic Biology, 1988
- Lactate Transporter Defect: A New Disease of MuscleScience, 1986
- The mechanism of lactate transport in human erythrocytesThe Journal of Membrane Biology, 1978
- Stereoselective, SH-dependent transfer of lactate in mammalian erythrocytesBiochimica et Biophysica Acta (BBA) - Biomembranes, 1978
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976