QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services 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 Howard, A. Articles by Hirst, B. H. Search for Related Content PubMed PubMed Citation Articles by Howard, A. Articles by Hirst, B. H.

---

Nutrient-Gene Interactions

Increased Expression of Specific Intestinal Amino Acid and Peptide Transporter mRNA in Rats Fed by TPN Is Reversed by GLP-2¹

Alison Howard, Robert A. Goodlad^*, Julian R. F. Walters, Dianne Ford and Barry H. Hirst²

Institute for Cell and Molecular Biosciences, University of Newcastle Medical School, Newcastle upon Tyne, UK; ^* Cancer Research UK, Lincoln’s Inn Fields, London, UK; and Faculty of Medicine, Imperial College London, UK

²To whom correspondence should be addressed. E-mail: barry.hirst{at}ncl.ac.uk.

Intestinal function depends on the presence of luminal nutrients and is altered during starvation and refeeding. Amino acids are essential for enterocytes, but the luminal supply is compromised with changes in dietary intake. To test the hypothesis that during periods of restricted luminal nutrient availability mucosal cells undergo adaptations aimed toward preserving amino acid supply, the expression of amino acid and peptide transporter mRNAs was quantified in rats with no oral intake, whose nutritional status was maintained with total parenteral nutrition (TPN). The role of the intestinotrophic hormone glucagon-like peptide-2 (GLP-2) was investigated in the adaptive responses. Rats were administered TPN with or without exogenous GLP-2. Amino acid and peptide transporter mRNAs in small intestine mucosa were measured by semiquantitative RT-PCR. Compared with orally fed rats, removal of luminal nutrition increased the expression of ASCT1, SAT2, and GLYT1 mRNAs in the duodenum and of ASCT2, EAAC1, NBAT, and PepT1 mRNAs in the ileum. CAT1, PAT1, and SN2 mRNA abundances were unaffected. GLP-2 reversed these effects. Three subgroups of transporters were identified by regional differences in response to TPN. This may reflect differing roles for substrates of transporters located apically and basally and along the proximal-distal axis of the intestine. The importance of maintaining amino acid supply for intestinal mucosal cells is illustrated.

KEY WORDS: • amino acid transport • parenteral nutrition • glucagon-like peptide-2

This article has been cited by other articles:

				K. A. Jackson, R. M. Helston, J. A. McKay, E. D. O'Neill, J. C. Mathers, and D. Ford Splice Variants of the Human Zinc Transporter ZnT5 (SLC30A5) Are Differentially Localized and Regulated by Zinc through Transcription and mRNA Stability J. Biol. Chem., April 6, 2007; 282(14): 10423 - 10431. [Abstract] [Full Text] [PDF]

				P. A. Kitchen, R. A. Goodlad, A. J. FitzGerald, N. Mandir, M. A. Ghatei, S. R. Bloom, J. Berlanga-Acosta, R. J. Playford, A. Forbes, and J. R.F. Walters Intestinal Growth in Parenterally-Fed Rats Induced by the Combined Effects of Glucagon-like Peptide 2 and Epidermal Growth Factor JPEN J Parenter Enteral Nutr, July 1, 2005; 29(4): 248 - 254. [Abstract] [Full Text] [PDF]