title: Local expression of AP/AngIV/IRAP and effect of AngIV on glucose-induced epithelial transport in human jejunal mucosa.
abstract: BACKGROUND
  Recently it was shown that the classic renin-angiotensin system (RAS) is locally expressed in small intestinal enterocytes and exerts autocrine control of glucose transport. The aim of this study was to investigate if key components for the Angiotensin III (AngIII) and IV (AngIV) formation enzymes and the AngIV receptor, insulin-regulated aminopeptidase (IRAP), are present in the healthy jejunal mucosa. A second aim was to investigate AngIV effects on glucose-induced mucosal transport in vitro.
  
  
  METHODS
  Enteroscopy with mucosal biopsy sampling was performed in healthy volunteers. ELISA, Western blotting and immunohistochemistry were used to assess the protein levels and localization. The functional effect of AngIV was examined in Ussing chambers.
  
  
  RESULTS
  The substrate Angiotensin II, the enzymes aminopeptidases-A, B, M as well as IRAP were detected in the jejunal mucosa. Immunohistochemistry localized the enzymes to the apical brush-border membrane whereas IRAP was localized in the subapical cytosolic compartment in the enterocyte. AngIV increased the glucose-induced electrogenic transport in vitro.
  
  
  CONCLUSIONS
  The present study indicates the presence of substrates and enzymes necessary for AngIV formation as well as the receptor IRAP in the jejunal mucosa. The functional data suggest that AngIV regulates glucose uptake in the healthy human small intestine.
authors: Institute of Physiology and Pharmacology, Medical Academy, Lithuanian University of Health Sciences, Kaunas, Lithuania Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors: M
authors: M
authors: Malinauskas
authors: Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors: V
authors: V
authors: Wallenius
authors: Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden.
authors: L
authors: L
authors: Fändriks
authors: Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden anna.casselbrant@gastro.gu.se.
authors: A
authors: A
authors: Casselbrant
mesh_terms: D000293:Adolescent; D000328:Adult; D000626:Aminopeptidases / Q000378:metabolism*; D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D015153:Blotting, Western; D010122:Cystinyl Aminopeptidase / Q000378:metabolism*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism*; D008297:Male; D012084:Renin-Angiotensin System / Q000187:drug effects; D055815:Young Adult
chemical_list: D000804:Angiotensin II; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-; D000626:Aminopeptidases; D010122:Cystinyl Aminopeptidase; C105964:leucyl-cystinyl aminopeptidase; D005947:Glucose
keywords: Aminopeptidase; IRAP; Ussing chambers; angiotensin III; angiotensin IV; human jejunal epithelium