Biomaterial Database

Relatively high biliary secretory maximum for non-micelle-forming bile acid: possible significance for mechanism of secretion. 1986

E R O'Máille, and A F Hofmann

Because of the formation of mixed micelles, the effective (i.e. monomeric, intermicellar) concentration of bile acid in bile is only a small fraction of the total concentration: this factor could be of critical importance for the net hepatic transport of the natural bile acids (especially transport across the canalicular membrane, which is hypothesized to be passive). To assess the influence of micelle formation on bile acid secretion, the rate-limiting canalicular transport of the natural, micelle-forming bile acid, cholyltaurine, was compared with that of the artificial non-micelle-forming bile acid, dehydrocholyltaurine (which undergoes partial reductive metabolism), in the anaesthetized rat with a bile fistula. The derivatives of dehydrocholyltaurine shared the same biliary transport system as cholyltaurine and had a secretory maximum (22 +/- 4.7 (S.D.) mumol/min . kg, n = 12) which was significantly greater than that of cholyltaurine (15 +/- 1.2, n = 6) (P less than 0.01). The biliary secretion rates of phospholipid and cholesterol during maximal secretion of dehydrocholyltaurine derivatives were not raised over control values; 3 alpha-hydroxy, 7,12-dioxocholanoate (the taurine conjugate of which accounted for about 70-80% of the total bile acid in bile during dehydrocholyltaurine infusion) has also been shown in vitro to be non-micelle forming. These results would seem to indicate that micelle formation in bile is not essential for the effective net translocation of bile acid by the specific canalicular membrane carriers.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008823	Micelles	Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.	Micelle
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001646	Bile	An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.	Biliary Sludge,Sludge, Biliary
D001647	Bile Acids and Salts	Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.	Bile Acid,Bile Salt,Bile Salts,Bile Acids,Acid, Bile,Acids, Bile,Salt, Bile,Salts, Bile
D001648	Bile Canaliculi	Minute intercellular channels that occur between liver cells and carry bile towards interlobar bile ducts. Also called bile capillaries.	Bile Canaliculus,Canaliculi, Bile,Canaliculus, Bile
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
D013656	Taurocholic Acid	The product of conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and cholerectic.	Cholyltaurine,Taurine Cholate,Taurocholate,Sodium Taurocholate,Taurocholate Sodium,Taurocholic Acid, (5 alpha)-Isomer,Taurocholic Acid, (7 beta)-Isomer,Taurocholic Acid, Monolithium Salt,Taurocholic Acid, Monosodium Salt,Taurocholate, Sodium
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus