title: Immuno-localization of H+/peptide cotransporter in rat digestive tract.
abstract: In the mammalian digestive tract, small peptides are absorbed by a H+-coupled peptide transport system. Using an antibody against the rat H+/peptide cotransporter (PepT1), we examined the localization of PepT1 immunohistochemically along the rat digestive tract. PepT1 was detected in the small intestine (duodenum, jejunum, and ileum), but not in the esophagus, stomach, colon, or rectum. PepT1 was especially enriched in the villi, where it was localized in the brush border of the absorptive epithelial cells. PepT1 was not detected in the mucus-secreting goblet cells or less-differentiated epithelial cells in the crypts. These observations show that PepT1 is specific to the brush border of the differentiated absorptive epithelial cells and suggest that H+-coupled uptake of small peptides and peptide-like drugs occurs at the apical membrane of these cells in the small intestine.
authors.affiliation: First Department of Surgery, Gunma University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ogihara
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: B C
authors.initials: BC
authors.lastname: Shin
authors.forename: T
authors.initials: T
authors.lastname: Terado
authors.forename: S
authors.initials: S
authors.lastname: Takenoshita
authors.forename: Y
authors.initials: Y
authors.lastname: Nagamachi
authors.forename: K
authors.initials: K
authors.lastname: Inui
authors.forename: K
authors.initials: K
authors.lastname: Takata
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D003106:Colon / Q000378:metabolism; D004386:Duodenum / Q000378:metabolism; D004947:Esophagus / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005753:Gastric Mucosa / Q000378:metabolism; D007082:Ileum / Q000378:metabolism; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism; D007672:Kidney Cortex / Q000378:metabolism; D007679:Kidney Medulla / Q000378:metabolism; D008297:Male; D008322:Mammals; D008871:Microvilli / Q000378:metabolism*; D000074011:Peptide Transporter 1; D051381:Rats; D017207:Rats, Sprague-Dawley; D012007:Rectum / Q000378:metabolism; D027981:Symporters
chemical_list: D002352:Carrier Proteins; D000074011:Peptide Transporter 1; C489940:Slc15a1 protein, rat; D027981:Symporters