期刊
JOURNAL OF SURGICAL RESEARCH
卷 156, 期 1, 页码 123-128出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jss.2009.03.052
关键词
peptide transporter 1; PEPT1; diurnal rhythm; rat; small intestine; protein absorption; short peptides
类别
资金
- NIDDK NIH HHS [R01 DK039337, R01 DK 39337-18, R01 DK039337-18] Funding Source: Medline
Background. Protein is absorbed primarily as di/tripeptides, which are transported into the enterocyte exclusively by H+/peptide cotransporter 1 (PEPT1). Diurnal changes in expression and function of several other mucosal transporters occur in rat. Diurnal variations in mRNA, protein, and transport function of PEPT1 occur in rat duodenum and jejunum, but not in ileum. Methods. Mucosal levels of mRNA and protein were determined at 9 AM, 3 PM, 9 PM, and 3 AM (n = 6 each) by real time RT-PCR and Western blotting, respectively, in rats maintained in a 12-h light/dark room [light 6 AM to 6 PM]; transporter-mediated uptake of dipeptide (Gly-Sar) was also measured by everted sleeve technique. Results. mRNA transcripts of PEPT1 and Gly-Sar uptake varied diurnally in duodenum and jejunum (peak at 3 PM, P < 0.05), but not in ileum; maximal uptake was in jejunum. V-max (nmol/cm/min) was greater at 3 PM and 9 PM compared with 9 AM (3 PM versus 9 AM: 104 versus 62 in duodenum, and 185 versus 101 in jejunum; P < 0.03); K-m was unchanged across time points or locations. Protein levels varied minimally in jejunum and ileum with peaks at 9 PM and 3 AM. Conclusion. Gene expression and transport function of PEPT1 vary diurnally in duodenum and jejunum in temporal association with nocturnal feeding of rats. (C) 2009 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据