Role of Vagal Innervation in Diurnal Rhythm of Intestinal Peptide Transporter 1 (PEPT1)
Autor: | Ye Zheng, Judith A. Duenes, Michael G. Sarr, Jeffrey S. Scow, Hisham G. Qandeel, David J. Hernandez, Fernando Alonso |
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Rok vydání: | 2009 |
Předmět: |
Male
medicine.medical_specialty Duodenum Peptide Ileum Tripeptide Vagotomy Peptide Transporter 1 digestive system Article Internal medicine medicine Animals Circadian rhythm chemistry.chemical_classification Symporters biology digestive oral and skin physiology Peptide transporter 1 Gastroenterology Vagus Nerve Circadian Rhythm Rats Vagus nerve Jejunum medicine.anatomical_structure Endocrinology chemistry Rats Inbred Lew Symporter biology.protein Surgery |
Zdroj: | Journal of Gastrointestinal Surgery. 13:1976-1985 |
ISSN: | 1873-4626 1091-255X |
Popis: | Protein is absorbed predominantly as di/tripeptides via H(+)/peptide cotransporter-1 (PEPT1). We demonstrated previously diurnal variations in expression and function of duodenal and jejunal but not ileal PEPT1; neural regulation of this pattern is unexplored.Complete abdominal vagotomy abolishes diurnal variations in gene expression and transport function of PEPT1.Twenty-four rats maintained in a 12-h light/dark room [6AM-6PM] underwent abdominal vagotomy; 24 other rats were controls. Four weeks later, mucosal levels of mRNA and protein were measured at 9AM, 3PM, 9PM, and 3AM (n = 6 each) by quantitative real-time PCR and Western blots, respectively; transporter-mediated uptake of dipeptide (Gly-Sar) was measured by the everted-sleeve technique.Diurnal variation in mRNA, as in controls, was retained post-vagotomy in duodenum and jejunum (peak at 3PM, p0.05) but not in ileum. Diurnal variations in expression of protein and Gly-Sar uptake, however, were absent post-vagotomy (p0.3). Similar to controls, maximal uptake was in jejunum after vagotomy (V (max), nmol/cm/min: jejunum vs. duodenum and ileum; 163 vs. 88 and 71 at 3AM; p0.04); K (m) remained unchanged.Vagal innervation appears to mediate in part diurnal variations in protein expression and transport function of PEPT1, but not diurnal variation in mRNA expression of PEPT1. |
Databáze: | OpenAIRE |
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