title: Transepithelial transports of rare sugar D-psicose in human intestine.
abstract: D-Psicose (Psi), the C3-epimer of D-fructose (Fru), is a noncalorie sugar with a lower glycemic response. The trans-cellular pathway of Psi in human enterocytes was investigated using a Caco-2 cell monolayer. The permeation rate of Psi across the monolayer was not affected by the addition of phlorizin, an inhibitor of sugar transporter SGLT1, whereas it was accelerated by treatment with forskolin, a GLUT5-gene inducer, clearly showing that GLUT5 is involved in the transport of Psi. The permeability of Psi was suppressed in the presence of D-glucose (Glc) and Fru, suggesting that the three monosaccharides are transported via the same transporter. Since GLUT2, the predominant sugar transporter on the basolateral membrane of enterocytes, mediates the transport of Glc and Fru, Psi might be mediated by GLUT2. The present study shows that Psi is incorporated from the intestinal lumen into enterocytes via GLUT5 and is released to the lamina propria via GLUT2.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Kita-gun, Kagawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hishiike
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ogawa
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hayakawa
authors.forename: Daichi
authors.initials: D
authors.lastname: Nakajima
authors.forename: Siwaporn
authors.initials: S
authors.lastname: O'Charoen
authors.forename: Hisaka
authors.initials: H
authors.lastname: Ooshima
authors.forename: Yuanxia
authors.initials: Y
authors.lastname: Sun
mesh_terms: D001692:Biological Transport; D018938:Caco-2 Cells; D020895:Enterocytes / Q000737:chemistry / Q000378:metabolism*; D005632:Fructose / Q000737:chemistry / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D051296:Glucose Transporter Type 5 / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000737:chemistry; D007700:Kinetics; D010539:Permeability
chemical_list: D051273:Glucose Transporter Type 2; D051296:Glucose Transporter Type 5; C003243:psicose; D005632:Fructose; D005947:Glucose