title: Intestinal inflammation induces adaptation of P-glycoprotein expression and activity.
abstract: Recent studies suggest that P-glycoprotein (Pgp) encoded by MDR1 gene, may be an important factor in the pathogenesis of inflammatory bowel disease (IBD). In this study, we investigated intestinal Pgp expression and activity: (1) in IL10 deficient (IL10(-/-)) mice which spontaneously develop intestinal inflammation affecting the small and large intestine and (2) in DSS (dextran sodium sulfate)-induced rat colitis. In IL10(-/-) enterocolitis mice, rhodamine 123 efflux was reduced by two to three-fold along the small and large intestine. This decrease was associated with a reduction in membrane's Pgp protein levels. A similar three-fold decrease in Pgps activity and expression was observed in the proximal colon in DSS-induced colitis in rats. However, in the non-inflamed ileum in DSS-induced rat colitis, epithelial cell's Pgp activity and protein levels were unexpectedly increased. This effect was specific to local inflammation since LPS induced systemic inflammation did affect neither the intestinal rho 123 efflux transport nor the abundance of the Pgp protein. These data demonstrate for the first time, an impaired function of epithelial Pgp in IL10 deficient enterocolitis mice. They also show an increase in Pgps activity in the non-inflamed ileum in the DSS-induced rat colitis, which may represent an adaptive mechanism to compensate the impaired activity of Pgp in the colon.
authors.affiliation: UPRES 2706, Faculté de Pharmacie, Laboratoire de Pharmacie Clinique, 5 Rue Jean Baptiste Clément, Chatenay-Malabry 92 296, France. marion.buyse@cep.u-psud.fr <marion.buyse@cep.u-psud.fr>
authors.forename: Marion
authors.initials: M
authors.lastname: Buyse
authors.forename: Genia
authors.initials: G
authors.lastname: Radeva
authors.forename: André
authors.initials: A
authors.lastname: Bado
authors.forename: Robert
authors.initials: R
authors.lastname: Farinotti
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis* / Q000502:physiology; D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D016264:Dextran Sulfate / Q000633:toxicity; D004760:Enterocolitis / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D016264:Dextran Sulfate