title: Expression and localization of the multidrug resistance-associated protein 3 in rat small and large intestine.
abstract: Multidrug resistance-associated protein 3 (MRP3; symbol ABCC3), has been shown to mediate ATP-dependent transport of organic anions including 17beta-glucuronosyl estradiol, glucuronosyl bilirubin, monovalent, and sulfated bile salts. MRP3 mRNA expression was reported in rat intestine suggesting a role of MRP3 in the intestinal transport. We examined the expression and localization of MRP3 in rat small and large intestine by RT-PCR, immunofluorescence, and immunoblot analysis. MRP3 was identified in all intestinal segments by RT-PCR. MRP3 expression was low in duodenum and jejunum but markedly increased in ileum and colon. With the use of a rat MRP3 specific antibody, MRP3 was localized to the basolateral domains of enterocytes. Immunofluorescence analysis and immunoblot analysis confirmed a strong expression of rat MRP3 in ileum and colon. In contrast, MRP2 was predominantly expressed in the proximal segments of rat small intestine. Our findings demonstrate a high expression of rat MRP3 in ileum and colon and provide evidence for an involvement of MRP3 in the ATP-dependent transport of organic anions, including bile salts from the enterocyte into blood.
authors.affiliation: Department of Gastroenterology, University of Heidelberg, 69115 Heidelberg, Germany. Daniel_Rost@med.uni-heidelberg.de
authors.forename: Daniel
authors.initials: D
authors.lastname: Rost
authors.forename: Sven
authors.initials: S
authors.lastname: Mahner
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Stremmel
mesh_terms: D000818:Animals; D003106:Colon / Q000737:chemistry; D004386:Duodenum / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D007082:Ileum / Q000737:chemistry; D015151:Immunoblotting; D007413:Intestinal Mucosa / Q000737:chemistry / Q000378:metabolism; D007422:Intestines / Q000737:chemistry*; D007583:Jejunum / Q000737:chemistry; D008297:Male; D008856:Microscopy, Fluorescence; D024101:Mitochondrial Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000032:analysis* / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D014018:Tissue Distribution
chemical_list: D024101:Mitochondrial Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C093947:MRP2 protein, S cerevisiae; C114462:multidrug resistance-associated protein 3