TY - JOUR
T1 - Role of vagal innervation in diurnal rhythm of intestinal peptide transporter 1 (PEPT1)
AU - Qandeel, Hisham G.
AU - Alonso, Fernando
AU - Hernandez, David J.
AU - Duenes, Judith A.
AU - Zheng, Ye
AU - Scow, Jeffrey
AU - Sarr, Michael G.
N1 - Funding Information:
Acknowledgments We would like to thank the Mary Elizabeth Groff Surgical Medical Research and Education Charitable Trust for the generous funding in support of this work. Also, we thank Deborah Frank for her superb secretarial expertise.
Funding Information:
Research supported in part by a grant from the Mary E. Groff Foundation and NIH R01 DK 39337-18 (MGS) H.G.Qandeel.F.Alonso.D.J.Hernandez.J.A.Duenes. Y. Zheng.J. S. Scow.M. G. Sarr (*) Gastrointestinal Research Unit and Department of Surgery, Mayo Clinic (GU 10-01), 200 1st Street SW, Rochester, MN 55905, USA e-mail: [email protected]
PY - 2009
Y1 - 2009
N2 - Background 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. Hypothesis Complete abdominal vagotomy abolishes diurnal variations in gene expression and transport function of PEPT1. Methods 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. Results Diurnal variation in mRNA, as in controls, was retained post-vagotomy in duodenum and jejunum (peak at 3PM, p<0.05) but not in ileum. Diurnal variations in expression of protein and Gly-Sar uptake, however, were absent post-vagotomy (p>0.3). 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; p<0.04); K m remained unchanged. Conclusions 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.
AB - Background 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. Hypothesis Complete abdominal vagotomy abolishes diurnal variations in gene expression and transport function of PEPT1. Methods 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. Results Diurnal variation in mRNA, as in controls, was retained post-vagotomy in duodenum and jejunum (peak at 3PM, p<0.05) but not in ileum. Diurnal variations in expression of protein and Gly-Sar uptake, however, were absent post-vagotomy (p>0.3). 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; p<0.04); K m remained unchanged. Conclusions 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.
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U2 - 10.1007/s11605-009-0984-6
DO - 10.1007/s11605-009-0984-6
M3 - Article
C2 - 19707837
AN - SCOPUS:77952968140
SN - 1091-255X
VL - 13
SP - 1976
EP - 1985
JO - Journal of Gastrointestinal Surgery
JF - Journal of Gastrointestinal Surgery
IS - 11
ER -