title: Glycodeoxycholate transport in brush border membrane vesicles isolated from rat jejunum and ileum.
abstract: The transport of the bile salt, glycodeoxycholate, was studied in vesicles derived from rat jejunal and ileal brush border membranes using a rapid filtration technique. The uptake was osmotically sensitive, linearly related to membrane protein and resembled D-glucose transport. In ileal, but not jejunal, vesicles glycodeoxycholate uptake showed a transient vesicle/medium ratio greater than 1 in the presence of an initial sodium gradient. The differences between glycodeoxycholate uptake in the presence and absence of a Na+ gradient yielded a saturable transport component. Kinetic analysis revealed a Km value similar to that described previously in everted whole intestinal segments and epithelial cells isolated from the ileum. These findings support the existence of a transport system in the brush border membrane that: (1) reflects kinetics and characteristics of bile salt transport in intact intestinal preparations, and (2) catalyzes the co-transport of Na+ and bile salt across the ileal membrane in a manner analogous to D-glucose transport.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006002:Glycodeoxycholic Acid / Q000378:metabolism*; D007082:Ileum / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D007583:Jejunum / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D009994:Osmolar Concentration; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000494:pharmacology
chemical_list: D008565:Membrane Proteins; D003840:Deoxycholic Acid; D006002:Glycodeoxycholic Acid; D012964:Sodium; D005947:Glucose; D011188:Potassium