Neither intestinal sequestration of bile acids nor common bile duct ligation modulate the expression and function of the rat ileal bile acid transporter.
The regulatory responses of bile acid (BA) transport in the terminal ileum to perturbations in BA homeostasis are complex, and conflicting results have been reported by different investigators. These studies were designed to examine the response of this system to a reduction in ileal bile salt concentrations at both a functional and molecular level. Common bile duct ligation (BDL) or feeding of a novel bile acid-binding compound, GT31-104HB, for 7 days were used to reduce ileal apical membrane bile salt flux. Apical bile acid transport function was assessed by examining sodium-dependent uptake of [3H]-taurocholate (TC) into brush border membrane vesicles (BBMV). Expression of the apical sodium-dependent bile acid transporter (ASBT) and the ileal lipid-binding protein (ILBP) were assessed by Western blotting with quantitation using [125I]-labeled secondary antibody and a phosphorimager. Neither common BDL nor intestinal sequestration of BA led to a change in ileal bile acid transport function or the expression of the ASBT or the ILBP. These results indicate that a reduction in presentation of bile salts to the apical surface of the terminal ileum does not modulate the expression of the genes involved in their transport.
Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA.
M
M
Arrese
M
M
Trauner
R J
RJ
Sacchiero
M W
MW
Crossman
B L
BL
Shneider
D000499:Allylamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001647:Bile Acids and Salts / Q000502:physiology*; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002756:Cholagogues and Choleretics / Q000494:pharmacology*; D002779:Cholestasis / Q000378:metabolism / Q000503:physiopathology*; D000069472:Colesevelam Hydrochloride; D003135:Common Bile Duct / Q000502:physiology*; D006913:Hydroxysteroid Dehydrogenases; D007082:Ileum; D007413:Intestinal Mucosa / Q000187:drug effects / Q000502:physiology*; D008562:Membrane Glycoproteins; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D029363:Organic Anion Transporters, Sodium-Dependent; D051381:Rats; D017207:Rats, Sprague-Dawley; D027981:Symporters; D013656:Taurocholic Acid / Q000378:metabolism*; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
D000499:Allylamine; D001647:Bile Acids and Salts; D002352:Carrier Proteins; D002756:Cholagogues and Choleretics; D000069472:Colesevelam Hydrochloride; D006913:Hydroxysteroid Dehydrogenases; D008562:Membrane Glycoproteins; D029363:Organic Anion Transporters, Sodium-Dependent; D027981:Symporters; D013656:Taurocholic Acid; C037643:bile acid binding proteins; C071908:sodium-bile acid cotransporter; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)