Taurochenodeoxycholic acid

TDCA taurodeoxycholic acid, TCDCA taurochenodeoxycholic acid,... 

Vibrio anguillarum glu, gin, gly, his, ile, leu, ser, fin, L-fucose, D-glucose, D-mannose, D-xylose, taurocholic acid, taurochenodeoxycholic acid 55... 

Secondary ion mass spectrometry Tuberculosis Taurocholic acid Taurochenodeoxycholic acid... 

The possibility that the biosynthesis of bile acids is regulated by a negative feedback mechanism was supported by early experiments by Thompson and Vars [206] and Eriksson [207], who showed that the rate of bile acid synthesis in rats increased about 10-fold when a bile fistula is made. Bergstrom and Danielsson demonstrated that duodenal infusion of taurochenodeoxycholic acid in bile fistula rats restored the increased synthesis to a normal rate [208]. Danielsson et al. [44] showed that the cholesterol 7a-hydroxylase activity increased in parallel with the bile acid synthesis after cannulation of the bile duct in rats. In a subsequent work by Mosbach et al., it was reported that the incorporation of isotope from labelled acetate, mevalonate and cholesterol but not from labelled 7a-hydroxycholesterol into bile acids was inhibited by duodenal infusion of taurocholate to bile fistula rats [209]. The incorporation of isotope from labelled acetate, mevalonate and cholesterol but not from labelled 7a-hydroxycholesterol was stimulated in perfused livers of cholestyramine-treated rabbits [210]. It was concluded that there are essentially no rate-limiting steps beyond 7a-hydroxycholesterol in the biosynthesis of bile acids from acetate. Since both cholesterol and bile acid biosynthesis was subjected to negative feedback inhibition by bile acids, it cannot be excluded that inhibition of cholesterol biosynthesis precedes inhibition of the bile acid biosynthesis, and that the latter inhibition is secondary to the former. 

The specificity of the inhibitory effect of bile acids on bile acid formation has been studied by Danielsson [110]. Taurocholic acid, taurochenodeoxycholic acid and taurodeoxycholic acid, fed at the 1% level in the diet for 3-7 days, were found to inhibit cholesterol 7a-hydroxylase activity. Feeding taurohyodeoxycholic acid and... 

Araya Z, Wikvall K. 6alpha-hydroxylation of taurochenodeoxycholic acid and lithocholic acid by CYP3A4 in human liver microsomes. Biochim Biophys Acta 1999 1438 47-54. 

Taurochenodeoxycholic acid (Chenodeoxycholoyltaurine) C26H45N06S 499.71 182-184 (Na salt) + 9° (C2H5OH, Na salt) 516-35-8... 

The results of Shefer et al. (152) support the conclusion by Lee et al. (146) that taurochenodeoxycholic acid has an effect on bile acid formation in rats with a biliary fistula not entirely related to the physiological regulation of bile acid formation, since the concentration of taurochenodeoxycholic acid needed to repress bile acid biosynthesis is less than half of that of taurocholic acid. 

The biliary bile acids of germfree chicks have been shown by Haslewood (34) to be composed of approximately 80% taurochenodeoxycholic acid, 17% taurocholic acid, and 5% tauroallocholic acid. 

Electrophoresis on paper using a single buffer was applied to bile acid separation by Biserte et al. (41). The buffer system was made up of 30 ml of pyridine and 100 ml of glacial acetic acid in 5 liters of water. The pW was 3.9. In this system, cholic, glycocholic, taurocholic, and taurochenodeoxycholic acids were attracted toward the anode at rates increasing in the order named. Curiously, free deoxycholic acid remained at the origin. The locations of the bile acids on the paper were found by spraying with phosphomolybdic acid. Results with various animal biles were reported. 

The approximate Rf values and order of migration should be as follows glycoli-thocholic acid, 0.10 glycodeoxycholic acid, 0.17 glycochenodeoxycholic acid, 0.20 taurodeoxycholic acid, 0.23 taurochenodeoxycholic acid, 0.26 glycocholic acid, 0.31 and taurocholic acid, 0.38. 

In the presence of HDL, taurocholic (TC) and taurochenodeoxycholic acid (TCDC) were synthesized from HDL-Ch. The synthesis of TC and TCDC from HDL-Ch increased when higher concentrations of HDL were added, suppressing the utilization of endogenous cholesterol. In the presence of large amounts of HDL, HDL cholesterol was preferentially used and the endogenous cholesterol was no longer available. 

Key Words Chick-embryo hepatocytes. Cholesterol, HDL, Tauro-Cholic acid, Taurochenodeoxycholic acid. 

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