Vectorial transport of bile salts across MDCK cells expressing both rat Na+-taurocholate cotransporting polypeptide and rat bile salt export pump.
Article Details
- CitationCopy to clipboard
Mita S, Suzuki H, Akita H, Stieger B, Meier PJ, Hofmann AF, Sugiyama Y
Vectorial transport of bile salts across MDCK cells expressing both rat Na+-taurocholate cotransporting polypeptide and rat bile salt export pump.
Am J Physiol Gastrointest Liver Physiol. 2005 Jan;288(1):G159-67. Epub 2004 Aug 5.
- PubMed ID
- 15297262 [ View in PubMed]
- Abstract
Bile salts are predominantly taken up by hepatocytes via the basolateral Na(+)-taurocholate cotransporting polypeptide (NTCP/SLC10A1) and secreted into the bile by the bile salt export pump (BSEP/ABCB11). In the present study, we transfected rat Ntcp and rat Bsep into polarized Madin-Darby canine kidney cells and characterized the transport properties of these cells for eight bile salts. Immunohistochemical staining demonstrated that Ntcp was expressed at the basolateral domains, whereas Bsep was expressed at the apical domains. Basal-to-apical transport of taurocholate across the monolayer expressing only Ntcp and that coexpressing Ntcp/Bsep was observed, whereas the flux across the monolayer of control and Bsep-expressing cells was symmetrical. Basal-to-apical transport of taurocholate across Ntcp/Bsep-coexpressing monolayers was significantly higher than that across monolayers expressing only Ntcp. Kinetic analysis of this vectorial transport of taurocholate gave an apparent K(m) value of 13.9 +/- 4.7 microM for cells expressing Ntcp alone, which is comparable with 22.2 +/- 4.5 microM for cells expressing both Ntcp and Bsep and V(max) values of 15.8 +/- 4.2 and 60.8 +/- 9.0 pmol.min(-1).mg protein(-1) for Ntcp alone and Ntcp and Bsep-coexpressing cells, respectively. Transcellular transport of cholate, glycocholate, taurochenodeoxycholate, chenodeoxycholate, glycochenodeoxycholate, tauroursodeoxycholate, ursodeoxycholate, and glycoursodeoxycholate, but not that of lithocholate was also observed across the double transfectant. This double-expressing system can be used as a model to clarify vectorial transport of bile salts across hepatocytes under physiological conditions.
DrugBank Data that Cites this Article
- Drug Transporters
Drug Transporter Kind Organism Pharmacological Action Actions Cholic Acid Bile salt export pump Protein Humans UnknownSubstrateInhibitorInducerDetails Cholic Acid Sodium/bile acid cotransporter Protein Humans UnknownSubstrateInhibitorDetails Glycochenodeoxycholic Acid Bile salt export pump Protein Humans UnknownSubstrateInhibitorDetails Glycochenodeoxycholic Acid Sodium/bile acid cotransporter Protein Humans UnknownSubstrateDetails Taurocholic acid Bile salt export pump Protein Humans UnknownSubstrateInducerDetails Taurocholic acid Sodium/bile acid cotransporter Protein Humans UnknownSubstrateDetails Ursodeoxycholic acid Bile salt export pump Protein Humans UnknownSubstrateInhibitorInducerDetails Ursodeoxycholic acid Sodium/bile acid cotransporter Protein Humans UnknownSubstrateInhibitorDetails