Increased Expression of Specific Intestinal Amino Acid and Peptide Transporter mRNA in Rats Fed by TPN Is Reversed by GLP-2
| Autor: | Robert A. Goodlad, Barry H. Hirst, Julian R.F. Walters, Alison Howard, Dianne Ford |
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| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Amino Acid Transport Systems Glucagon-Like Peptides Gene Expression Medicine (miscellaneous) Ileum Biology Glucagon Intestinal mucosa Internal medicine Intestine Small Gene expression Glucagon-Like Peptide 2 medicine Animals RNA Messenger Intestinal Mucosa Rats Wistar chemistry.chemical_classification Nutrition and Dietetics Reverse Transcriptase Polymerase Chain Reaction Membrane Transport Proteins Transporter Glucagon-like peptide-2 Small intestine Rats Amino acid medicine.anatomical_structure Endocrinology chemistry Parenteral Nutrition Total Peptides |
| Zdroj: | The Journal of Nutrition. 134:2957-2964 |
| ISSN: | 0022-3166 |
| DOI: | 10.1093/jn/134.11.2957 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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