PathwayStep1605 PathwayStep1604 PathwayStep1606 PathwayStep1601 PathwayStep1600 PathwayStep1603 PathwayStep1602 PathwayStep1552 PathwayStep1599 Co-transport (influx) of bile salts and acids and sodium ions by ASBT Cytosolic cholate and chenodeoxycholate are conjugated with Coenzyme A (SLC27A5 BACS) Transport (influx) of glycocholate and taurocholate by OATP-8 Transport (influx) of glycocholate and taurocholate by OATP-C Transport (influx) of bile salts and acids by OATP-A Co-transport (influx) of bile salts and sodium ions by NTCP Transport (efflux) of bile salts by ABCC3 (MRP3) Cytosolic chenodeoxycholoyl-CoA or choloyl-CoA are conjugated with glycine or taurine Transport (efflux) of bile salts by ABCB11 (bile salt export pump) Recycling of bile acids and salts Authored: Jassal, B, 2005-03-09 13:42:30 Edited: D'Eustachio, P, 2007-03-09 21:29:31 GENE ONTOLOGYGO:0015721 Of the 20-40 grams of bile salts released daily by the liver, all but approximately 0.5 grams are reabsorbed from the intestine, returned to the liver, and re-used. This recycling involves a series of transport processes: uptake by enterocytes mediated by ASBT (SLC10A2), traversal of the enterocyte cytosol mediated by ileal bile acid binding protein (I-BABP - FABP6), efflux from enterocytes mediated by MRP3 (ABCC3), travel through the portal blood as a complex with albumin, and uptake by hepatocytes mediated by Na+-taurocholate transporting protein (NTPC - SLC10A1) and, to a lesser extent by organic anion transporting proteins A, C, and 8 (OATPA - SLCO1A2, OATPC - SLCO1B1, and OATP-8 - SLCO1B3). Once returned to the hepatocyte cytosol, bile acids (generated in the intestine by the action of bacteria on secreted bile salts) are activated by conjugation with coenzyme A, then coupled to glycine or taurine, regenerating bile salts for re-export into the bile, mediated by the bile salt export pump, ABCB11 (Kullak-Ublick et al. 2004; Mihalik et al. 2002; Trauner and Boyer 2003). Unmodified bile salts returned to the hepatocyte cytosol can be re-exported by ABCB11 without further modification.<br> Pubmed11980911 Pubmed12663868 Pubmed14699511 Pubmed621437 Pubmed8034703 Reactome Database ID Release 43159418 Reactome, http://www.reactome.org ReactomeREACT_11042 Reviewed: D'Eustachio, P, 2007-04-30 14:43:26