title: Transporter-mediated intestinal absorption of fexofenadine in rats.
abstract: Both influx and efflux transporters are thought to be involved in the intestinal absorption of fexofenadine. The present study examined the influx transporter-mediated intestinal absorption of fexofenadine in rats, focusing on the role of rat oatp3 (Oatp1a5). The intestinal permeability of fexofenadine was evaluated by means of the Ussing chamber method in the presence of a P-glycoprotein inhibitor to block efflux transport. The permeability of fexofenadine from the mucosal to the serosal side was higher than that from the serosal side to the mucosal side. Transport of fexofenadine was saturable, and was significantly decreased by an organic anion transporting polypeptide (oatp) inhibitor. Furthermore, uptake of fexofenadine by Xenopus oocytes expressing rat oatp3 was significantly greater than that by water-injected oocytes, and the affinity of oatp3 for fexofenadine (Km) was about 60 microM, which is comparable with the value obtained by the Ussing chamber method using rat intestinal tissues. These results indicate that oatp3 plays a role as an influx transporter in the intestinal absorption of fexofenadine in rats.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science (RIKADAI), Noda, Chiba, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Nozawa
authors.forename: Takeru
authors.initials: T
authors.lastname: Wakasawa
authors.forename: Tomoji
authors.initials: T
authors.lastname: Maeda
authors.forename: Ikumi
authors.initials: I
authors.lastname: Tamai
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors; D000818:Animals; D018926:Anti-Allergic Agents / Q000493:pharmacokinetics; D000935:Antifungal Agents / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004970:Estrone / Q000031:analogs & derivatives / Q000494:pharmacology; D007408:Intestinal Absorption / Q000502:physiology*; D007654:Ketoconazole / Q000494:pharmacology; D008297:Male; D009865:Oocytes / Q000187:drug effects; D029362:Organic Anion Transporters, Sodium-Independent / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D016593:Terfenadine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D014981:Xenopus / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018926:Anti-Allergic Agents; D000935:Antifungal Agents; D029362:Organic Anion Transporters, Sodium-Independent; C421143:Slco1a5 protein, rat; D004970:Estrone; D016593:Terfenadine; C093230:fexofenadine; C017296:estrone sulfate; D007654:Ketoconazole