AJP - GI Journal of Neurophysiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Gastrointest Liver Physiol 281: G144-G150, 2001;
0193-1857/01 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (24)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Said, H. M.
Right arrow Articles by Dudeja, P. K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Said, H. M.
Right arrow Articles by Dudeja, P. K.
Vol. 281, Issue 1, G144-G150, July 2001

Mechanism of thiamine uptake by human colonocytes: studies with cultured colonic epithelial cell line NCM460

Hamid M. Said, Alvaro Ortiz, Veedamali S. Subramanian, Ellis J. Neufeld, Mary Pat Moyer, and Pradeep K. Dudeja

Department of Veterans Affairs Medical Center, Long Beach, California 90822; University of California School of Medicine, Irvine, California 92697; Children's Hospital-Harvard Medical School, Boston, Massachusetts 02115; INCELL Corporation, San Antonio, Texas 78249; and Westside Department of Veterans Affairs Medical Center- University of Illinois at Chicago, Chicago, Illinois 60612

Thiamine (vitamin B1) is essential for normal cellular functions and growth. Mammals cannot synthesize thiamine and thus must obtain the vitamin via intestinal absorption. The intestine is exposed to a dietary thiamine source and a bacterial source in which the vitamin is synthesized by the normal microflora of the large intestine. Very little is known about thiamine uptake in the large intestine. The aim of this study was, therefore, to address this issue. Our results with human-derived colonic epithelial NCM460 cells as a model system showed thiamine uptake to be 1) temperature- and energy dependent, 2) Na+ independent, 3) increased with increasing buffer pH from 5 to 8 and after cell acidification but inhibited by amiloride, 4) saturable as a function of concentration, 5) inhibited by thiamine structural analogs but not by unrelated organic cations, and 6) inhibited by modulators of a Ca2+/calmodulin-mediated pathway. NCM460 cells and native human colonic mucosa expressed the recently cloned human thiamine transporter THTR-1 (product of the SLC19A2 gene) at both mRNA and protein levels. These results demonstrate for the first time that human NCM460 colonocytes possess a specific carrier-mediated system for thiamine uptake that appears to be under the regulation of an intracellular Ca2+/calmodulin-mediated pathway. It is suggested that bacterially synthesized thiamine in the large intestine may contribute to thiamine nutrition of the host, especially toward cellular nutrition of the local colonocytes.

colonic thiamine transport


This article has been cited by other articles:


Home page
 J. Nutr.Home page
S. J. D. O'Keefe, J. Ou, S. Aufreiter, D. O'Connor, S. Sharma, J. Sepulveda, T. Fukuwatari, K. Shibata, and T. Mawhinney
Products of the Colonic Microbiota Mediate the Effects of Diet on Colon Cancer Risk
J. Nutr., November 1, 2009; 139(11): 2044 - 2048.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
B. Ashokkumar, N. D. Vaziri, and H. M. Said
Thiamin uptake by the human-derived renal epithelial (HEK-293) cells: cellular and molecular mechanisms
Am J Physiol Renal Physiol, October 1, 2006; 291(4): F796 - F805.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
S. M. Nabokina, M. L. Kashyap, and H. M. Said
Mechanism and regulation of human intestinal niacin uptake
Am J Physiol Cell Physiol, July 1, 2005; 289(1): C97 - C103.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
J. C. Reidling and H. M. Said
Adaptive regulation of intestinal thiamin uptake: molecular mechanism using wild-type and transgenic mice carrying hTHTR-1 and -2 promoters
Am J Physiol Gastrointest Liver Physiol, June 1, 2005; 288(6): G1127 - G1134.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
S. M. Nabokina and H. M. Said
Characterization of the 5'-regulatory region of the human thiamin transporter SLC19A3: in vitro and in vivo studies
Am J Physiol Gastrointest Liver Physiol, October 1, 2004; 287(4): G822 - G829.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
H. M. Said, K. Balamurugan, V. S. Subramanian, and J. S. Marchant
Expression and functional contribution of hTHTR-2 in thiamin absorption in human intestine
Am J Physiol Gastrointest Liver Physiol, March 1, 2004; 286(3): G491 - G498.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
H. M. Said, A. Ortiz, and T. Y. Ma
A carrier-mediated mechanism for pyridoxine uptake by human intestinal epithelial Caco-2 cells: regulation by a PKA-mediated pathway
Am J Physiol Cell Physiol, November 1, 2003; 285(5): C1219 - C1225.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
J. C. Reidling and H. M. Said
In vitro and in vivo characterization of the minimal promoter region of the human thiamin transporter SLC19A2
Am J Physiol Cell Physiol, September 1, 2003; 285(3): C633 - C641.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Gastrointest. Liver Physiol.Home page
K. Balamurugan and H. M. Said
Functional role of specific amino acid residues in human thiamine transporter SLC19A2: mutational analysis
Am J Physiol Gastrointest Liver Physiol, July 1, 2002; 283(1): G37 - G43.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online