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

This Article Full Text (PDF) 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 PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Vijayalakshmi, D. Articles by Belt, J. A. Search for Related Content PubMed PubMed Citation Articles by Vijayalakshmi, D. Articles by Belt, J. A. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 263, Issue 36, 19419-19423, 12, 1988

Sodium-dependent nucleoside transport in mouse intestinal epithelial cells. Two transport systems with differing substrate specificities

D Vijayalakshmi and JA Belt
Department of Biochemical and Clinical Pharmacology, St. Jude Children's Research Hospital, Memphis, Tennessee 38101.

Nucleoside transport was examined in freshly isolated mouse intestinal epithelial cells. The uptake of formycin B, the C nucleoside analog of inosine, was concentrative and required extracellular sodium. The initial rate of sodium-dependent formycin B transport was saturable with a Km of 45 +/- 3 microM. The purine nucleosides adenosine, inosine, guanosine, and deoxyadenosine were all good inhibitors of sodium-dependent formycin B transport with 50% inhibition (IC50) observed at concentrations less than 30 microM. Of the pyrimidine nucleosides examined, only uridine (IC50, 41 +/- 9 microM) was a good inhibitor. Thymidine and cytidine were poor inhibitors with IC50 values greater than 300 microM. Direct measurements of [3H]thymidine transport revealed, however, that the uptake of this nucleoside was also mediated by a sodium-dependent mechanism. Thymidine transport was inhibited by low concentrations of cytidine, uridine, adenosine, and deoxyadenosine (IC50 values less than 25 microM), but not by formycin B, inosine, or guanosine (IC50 values greater than 600 microM). These data indicate that there are two sodium-dependent mechanisms for nucleoside transport in mouse intestinal epithelial cells, and that formycin B and thymidine may serve as model substrates to distinguish between these transporters. Neither of these sodium-dependent transport mechanisms was inhibited by nitrobenzylmercaptopurine riboside (10 microM), a potent inhibitor of one of the equilibrative (facilitated diffusion) nucleoside transporters found in many cells.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				I. M. Larrayoz, A. Fernandez-Nistal, A. Garces, E. Gorraitz, and M. P. Lostao Characterization of the rat Na+/nucleoside cotransporter 2 and transport of nucleoside-derived drugs using electrophysiological methods Am J Physiol Cell Physiol, December 1, 2006; 291(6): C1395 - C1404. [Abstract] [Full Text] [PDF]

				I. Aymerich, M. Pastor-Anglada, and F. J. Casado Long Term Endocrine Regulation of Nucleoside Transporters in Rat Intestinal Epithelial Cells J. Gen. Physiol., October 25, 2004; 124(5): 505 - 512. [Abstract] [Full Text] [PDF]

				L. M. Mangravite, G. Xiao, and K. M. Giacomini Localization of human equilibrative nucleoside transporters, hENT1 and hENT2, in renal epithelial cells Am J Physiol Renal Physiol, May 1, 2003; 284(5): F902 - F910. [Abstract] [Full Text] [PDF]

				Y. Lai, A. H. Bakken, and J. D. Unadkat Simultaneous Expression of hCNT1-CFP and hENT1-YFP in Madin-Darby Canine Kidney Cells. LOCALIZATION AND VECTORIAL TRANSPORT STUDIES J. Biol. Chem., September 27, 2002; 277(40): 37711 - 37717. [Abstract] [Full Text] [PDF]

				G. Lee, S. Dallas, M. Hong, and R. Bendayan Drug Transporters in the Central Nervous System: Brain Barriers and Brain Parenchyma Considerations Pharmacol. Rev., December 1, 2001; 53(4): 569 - 596. [Abstract] [Full Text] [PDF]

				L. M. Mangravite, J. H. Lipschutz, K. E. Mostov, and K. M. Giacomini Localization of GFP-tagged concentrative nucleoside transporters in a renal polarized epithelial cell line Am J Physiol Renal Physiol, May 1, 2001; 280(5): F879 - F885. [Abstract] [Full Text] [PDF]

				M. Hong, L. Schlichter, and R. Bendayan A Na+-Dependent Nucleoside Transporter in Microglia J. Pharmacol. Exp. Ther., January 1, 2000; 292(1): 366 - 374. [Abstract] [Full Text]

				T. Burke, S. Lee, P. J. Ferguson, and J. R. Hammond Interaction of 2',2'-Difluorodeoxycytidine (Gemcitabine) and Formycin B with the Na+-Dependent and -Independent Nucleoside Transporters of Ehrlich Ascites Tumor Cells J. Pharmacol. Exp. Ther., September 1, 1998; 286(3): 1333 - 1340. [Abstract] [Full Text]

				J. Wang, S.-F. Su, M. J. Dresser, M. E. Schaner, C. B. Washington, and K. M. Giacomini Na+-dependent purine nucleoside transporter from human kidney: cloning and functional characterization Am J Physiol Renal Physiol, December 1, 1997; 273(6): F1058 - F1065. [Abstract] [Full Text] [PDF]

				S. A. Flanagan and K. A. Meckling-Gill Characterization of a Novel Na+-dependent, Guanosine-specific, Nitrobenzylthioinosine-sensitive Transporter in Acute Promyelocytic Leukemia Cells J. Biol. Chem., July 18, 1997; 272(29): 18026 - 18032. [Abstract] [Full Text] [PDF]

				S. L. Borgl and a. F. E. Parkinson Uptake and Release of [3H]Formycin B via Sodium-Dependent Nucleoside Transporters in Mouse Leukemic L1210/MA27.1 Cells J. Pharmacol. Exp. Ther., April 1, 1997; 281(1): 347 - 353. [Abstract] [Full Text]

				M. Che, D. F. Ortiz, and I. M. Arias Primary Structure and Functional Expression of a cDNA Encoding the Bile Canalicular, Purine-specific Na[IMAGE]-Nucleoside Cotransporter J. Biol. Chem., June 9, 1995; 270(23): 13596 - 13599. [Abstract] [Full Text] [PDF]