HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 289/4/C846    most recent 00112.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (23) Citing Articles via Google Scholar Google Scholar Articles by Gill, R. K. Articles by Dudeja, P. K. Search for Related Content PubMed PubMed Citation Articles by Gill, R. K. Articles by Dudeja, P. K.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

Expression and membrane localization of MCT isoforms along the length of the human intestine

Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois

Submitted 11 March 2005 ; accepted in final form 9 May 2005

Recent studies from our laboratory and others have demonstrated the involvement of monocarboxylate transporter (MCT)1 in the luminal uptake of short-chain fatty acids (SCFAs) in the human intestine. Functional studies from our laboratory previously demonstrated kinetically distinct SCFA transporters on the apical and basolateral membranes of human colonocytes. Although apical SCFA uptake is mediated by the MCT1 isoform, the molecular identity of the basolateral membrane SCFA transporter(s) and whether this transporter is encoded by another MCT isoform is not known. The present studies were designed to assess the expression and membrane localization of different MCT isoforms in human small intestine and colon. Immunoblotting was performed with the purified apical and basolateral membranes from human intestinal mucosa obtained from organ donor intestine. Immunohistochemistry studies were done on paraffin-embedded sections of human colonic biopsy samples. Immunoblotting studies detected a protein band of 39 kDa for MCT1, predominantly in the apical membranes. The relative abundance of MCT1 mRNA and protein increased along the length of the human intestine. MCT4 (54 kDa) and MCT5 (54 kDa) isoforms showed basolateral localization and were highly expressed in the distal colon. Immunohistochemical studies confirmed that human MCT1 antibody labeling was confined to the apical membranes, whereas MCT5 antibody staining was restricted to the basolateral membranes of the colonocytes. We speculate that distinct MCT isoforms may be involved in SCFA transport across the apical or basolateral membranes in polarized colonic epithelial cells.

monocarboxylate transporter; short-chain fatty acids; absorption; short-chain fatty acid transport; mammalian colon

This article has been cited by other articles:

				F. Annaba, Z. Sarwar, P. Kumar, S. Saksena, J. R. Turner, P. K. Dudeja, R. K. Gill, and W. A. Alrefai Modulation of ileal bile acid transporter (ASBT) activity by depletion of plasma membrane cholesterol: association with lipid rafts Am J Physiol Gastrointest Liver Physiol, February 1, 2008; 294(2): G489 - G497. [Abstract] [Full Text] [PDF]

				R. K. Gill, N. Pant, S. Saksena, A. Singla, T. M. Nazir, L. Vohwinkel, J. R. Turner, J. Goldstein, W. A. Alrefai, and P. K. Dudeja Function, expression, and characterization of the serotonin transporter in the native human intestine Am J Physiol Gastrointest Liver Physiol, January 1, 2008; 294(1): G254 - G262. [Abstract] [Full Text] [PDF]

				W. A. Alrefai, X. Wen, W. Jiang, J. P. Katz, K. A. Steinbrecher, M. B. Cohen, I. R. Williams, P. K. Dudeja, and G. D. Wu Molecular cloning and promoter analysis of downregulated in adenoma (DRA) Am J Physiol Gastrointest Liver Physiol, November 1, 2007; 293(5): G923 - G934. [Abstract] [Full Text] [PDF]

				S. R. Srinivas, P. D. Prasad, N. S. Umapathy, V. Ganapathy, and P. S. Shekhawat Transport of butyryl-L-carnitine, a potential prodrug, via the carnitine transporter OCTN2 and the amino acid transporter ATB0,+ Am J Physiol Gastrointest Liver Physiol, November 1, 2007; 293(5): G1046 - G1053. [Abstract] [Full Text] [PDF]

				Q. Wang and M. E. Morris The Role of Monocarboxylate Transporter 2 and 4 in the Transport of {gamma}-Hydroxybutyric Acid in Mammalian Cells Drug Metab. Dispos., August 1, 2007; 35(8): 1393 - 1399. [Abstract] [Full Text] [PDF]

				D. T. Thwaites and C. M. H. Anderson H+-coupled nutrient, micronutrient and drug transporters in the mammalian small intestine Exp Physiol, July 1, 2007; 92(4): 603 - 619. [Abstract] [Full Text] [PDF]

				R. Martin-Venegas, M. J. Rodriguez-Lagunas, P.-A. Geraert, and R. Ferrer Monocarboxylate Transporter 1 Mediates DL-2-Hydroxy-(4-Methylthio)Butanoic Acid Transport across the Apical Membrane of Caco-2 Cell Monolayers J. Nutr., January 1, 2007; 137(1): 49 - 54. [Abstract] [Full Text] [PDF]

				D. Kirat, J. Masuoka, H. Hayashi, H. Iwano, H. Yokota, H. Taniyama, and S. Kato Monocarboxylate transporter 1 (MCT1) plays a direct role in short-chain fatty acids absorption in caprine rumen J. Physiol., October 15, 2006; 576(2): 635 - 647. [Abstract] [Full Text] [PDF]

				D. Kirat and S. Kato Monocarboxylate transporter 1 (MCT1) mediates transport of short-chain fatty acids in bovine caecum Exp Physiol, September 1, 2006; 91(5): 835 - 844. [Abstract] [Full Text] [PDF]