Once synthesized in the liver, cholic and chenodeoxycholic acids undergo transformation within the enterohepatic circulation into other bile acids (BA) in a complex array of processes that include hepatic amidation with glycine or taurine and intestinal bacterial 7 dehydroxylation. Factors known to influence the steady state BA pool composition are the site, rate and mode of intestinal absorption of each BA, as well as hepatic uptake, transport and secretion: ultimately these factors determine the different BA composition of bile, serum, liver, urine, etc. (1). In humans, more than 12 different BA are usually present and they show considerable variation in physico-chemical properties such as solubility, detergency and lipophilicity. In general, the secondary BA products of intestinal 7 dehydroxylation are more detergent and lipophilic than the parent molecules: this would explain, for example, why high concentrations of the secondary BA,LCA and DCA can cause hepatotoxicity or intestinal diseases (2-4). The aim of this article is to present an overview of the current state of knowledge about the physico-chemical properties of BA, as well as the relationship between these properties, their kinetics and metabolism in the enterohepatic circulation, both in physiological and pathophysiological conditions. For ursodeoxycholic and tauroursodeoxycholic acids that are used therapeutically for cholesterol gallstone dissolution and cholestatic liver disease, the pharmacokinetics are discussed in relation to their physico-chemical behavior in aqueous solution.
Roda A., Gioacchini A.M., Manetta A.C., Cerre C., Montagnani M., Fini A. (1995). Bile acids: Physico-chemical properties, function and activity. ITALIAN JOURNAL OF GASTROENTEROLOGY, 27(6), 327-331.
Bile acids: Physico-chemical properties, function and activity
Roda A.;Montagnani M.;Fini A.
1995
Abstract
Once synthesized in the liver, cholic and chenodeoxycholic acids undergo transformation within the enterohepatic circulation into other bile acids (BA) in a complex array of processes that include hepatic amidation with glycine or taurine and intestinal bacterial 7 dehydroxylation. Factors known to influence the steady state BA pool composition are the site, rate and mode of intestinal absorption of each BA, as well as hepatic uptake, transport and secretion: ultimately these factors determine the different BA composition of bile, serum, liver, urine, etc. (1). In humans, more than 12 different BA are usually present and they show considerable variation in physico-chemical properties such as solubility, detergency and lipophilicity. In general, the secondary BA products of intestinal 7 dehydroxylation are more detergent and lipophilic than the parent molecules: this would explain, for example, why high concentrations of the secondary BA,LCA and DCA can cause hepatotoxicity or intestinal diseases (2-4). The aim of this article is to present an overview of the current state of knowledge about the physico-chemical properties of BA, as well as the relationship between these properties, their kinetics and metabolism in the enterohepatic circulation, both in physiological and pathophysiological conditions. For ursodeoxycholic and tauroursodeoxycholic acids that are used therapeutically for cholesterol gallstone dissolution and cholestatic liver disease, the pharmacokinetics are discussed in relation to their physico-chemical behavior in aqueous solution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.