The Enterohepatic Circulation of Bile Salts

Abstract

Bile salts secreted by the liver pass into the intestine, are absorbed in large part by the ileum, and return to the liver by way of the portal vein, thus completing a portal enterohepatic circulation (EHC). An extraportal EHC also exists, which is minor in health but may become a major determinant of bile metabolism in disease. A long-term monkey preparation allows direct measurement of bile volume, secretory rates of bile salts and biliary lipids, bile salt synthetic rates and pool size, and intestinal absorption in both the Substances secreted by the liv-1 er, absorbed by the intestine, and resecreted by the liver have an enterohepatic circulation (EHC). However, the degree to which a sub¬ stance undergoes EHC may vary from the extreme example of bile salts in which nearly all of the bile salt secreted into the intestine is reabsorbed and resecreted by the liver to compounds in which only a very small fraction of the total quan¬ tity secreted by the liver is reab¬ sorbed to reappear in the bile. From an anatomical point of view, the en¬ terohepatic circulation is divided into two clearly different pathways (Fig 1): the portal EHC and the extrapor¬ tal EHC. Compounds having a portal

The Selective Inhibition of Chenodeoxycholate Synthesis by Cholate Metabolites in Man

“…Previous evidence for the existence of a negative feedback regulation of bile acid synthesis in animals and man has been reviewed (Mosbach, 1972;Wilson, 1972;Small, Dowling & Redinger, 1972). The evidence in man is twofold.…”

Identification of a Mutation in the Ileal Sodium-dependent Bile Acid Transporter Gene That Abolishes Transport Activity

“…While the etiology of this "bile salt wasting" was not clear, a genetic defect in intestinal active bile acid transport was suggested as a possible cause (30). In a more recent study, an apparent defect in ileal bile acid uptake was documented in two boys with lifelong diarrhea and steatorrhea who had an ultrastructurally normal ileum (31).…”

Transport of organic anions in the liver. An update on bile acid, fatty acid, monocarboxylate, anionic amino acid, cholephilic organic anion, and anionic drug transport

“…Schiff (1870). Reports on this topic have appeared (Lindstedt 1957;Small et al 1972;Dowling 1972;Plaa 1975;Hofmann 1977;Kuipers et al 1985), and it now appears that nearly any kind of bile acid is taken up into hepatocytes. The picture of hepatic bile acid transport is still incomplete, especially the question of whether bile acids are taken up by a single or by multiple transporter proteins, and which bile acids share common pathways.…”