Taurine increases bile acid pool size and reduces bile saturation index in the hamster (original) (raw)
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Pharmacological research communications, 1987
This study reports the effect of short-term tauroursodeoxycholic acid (TUDCA) and of TUDCA with addition of taurine on the lipid composition of gallbladder bile, on cholesterol and bile acid synthesis and intestinal excretion, in the female hamsters. After either one or two weeks, the percentage of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in bile of treated hamsters significantly increased. Both treatments (TUDCA alone or TUDCA + taurine) decreased the percentage of cholic acid without affecting 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase or cholesterol 7 alpha-hydroxylase activities. Sterol and bile acid content of the feces collected during the period of the study did not show any difference. Bile acid glycine to taurine conjugation ratio (G/T ratio) in TUDCA treated animals was significantly higher in respect to controls after only one week of treatment. On the contrary, bile acid G/T ratio significantly decreased in the group of animals supplemented wi...
Clinical and experimental pharmacology & physiology, 2015
This study was designed to investigate the effects of dietary taurine on cholesterol metabolism in high cholesterol-fed rats. Male Sprague-Dawley rats were randomly divided into 2 dietary groups (n=6 in each group): a high-cholesterol diet containing 0.5% cholesterol and 0.15% sodium cholate, and a high-cholesterol diet with 5% (w/w) taurine. The experimental diets were given for two weeks. Taurine supplementation reduced the serum and hepatic cholesterol levels by 37% and 32%, respectively. Fecal excretion of bile acids was significantly increased in taurine-treated rats, compared with untreated rats. Biliary bile acid concentrations were also increased by taurine. Taurine supplementation increased taurine-conjugated bile acids by 61% and decreased glycine-conjugated bile acids by 53%, resulting in a significant decrease in the glycine/taurine (G/T) ratio. Among the taurine-conjugated bile acids, cholic acid and deoxycholic acid were significantly increased. In the liver, taurine s...
The effect of taurine depletion with guanidinoethanesulfonate on bile acid metabolism in the rat
Life Sciences, 1985
~dministration of guanidinoethanesulfonate (GES) to male rats for 5 weeks resulted in a 90% decrease in the hepatic taurine concentration. This depletion of hepatic taurine was associated with a 570% increase in the concentration of glycine-conjugated bile acids, a 30 % decrease in the concentration of taurine-conjugated bile acids, and an increase in the ratio of glycine-to taurine-conjugated bile acids from 0.046 to 0.45. The total concentration of bile salts in the bile and the turnover of cholic acid were not affected by administration of GE~ The data indicate that the taurine-depleted rat conserves taurine to some extent by using glycine instead of taurine for bile salt synthesis but not by decreasing the daily fractional turnover of bile acids.
Digestive Diseases and Sciences, 1994
Taurohyodeoxycholic acid is a natural 6et-hydroxylated bile acid with an apparent hydrophilicity intermediate between those of tauroursodeoxycholic and taurocholic acids. We investigated in the rat the hepatobiliary metabolism, choleretic properties, and biliary maximum secretory rate (SRmax) of taurohyodeoxycholic in comparison with these two bile salts. Each compound was infused intravenously, at a rate increased in a stepwise manner from 100 to 300 nmol/min/100 g body wt, in bile salt-depleted bile fistula rats. The three bile salts appeared rapidly starting with the infusion and increased to represent more than 95% of the total bile salts. No apparent biliary metabolites were formed. All the bile salts caused a dose-dependent increase in bile flow and biliary lipid output. The absolute increase in bile flow was lower in rats infused with taurohyodeoxycholic acid, yet the volume of bile formed per nanomole of secreted bile salt was 13.8 nl for taurohyodeoxycholic, 6.4 nl for tauroursodeoxycholic acid, and 10.9 nl for taurocholic. The SRm~, , values were 1080, 3240, and 960 nmol/min/100 g, respectively. At all infusion rates, taurohyodeoxycholic acid caused a greater (P < 0.001) secretion of biliary lecithin compared to the other bile salts. There were no significant differences in the biliary secretion of cholesterol and proteins. Electron microscopy showed the recruitment of vesicles and lamellar bodies around and within bile canaliculi. In conclusion, taurohyodeoxycholic promotes a biliary lecithin secretion greater than expected from physicochemical predictions, representing a novel secretory property with potential pharmacological relevance.
Comparative Biochemistry and Physiology Part A: Physiology, 1996
Dose-response curves for taurocholate and tauroursodeoxycholate were performed in rat and rabbit livers to get more insight into species differences in the hepatic bile acid uptake. The bile acids showed saturation kinetics in both animals, the V,,, in rat being higher than in rabbit and the K, being lower in the rat than in the rabbit for both the bile acids, with no significant difference in the hepatic cells morphometric parameters. Therefore, it is possible that differences in the kinetic parameters are related to the number and, to a lesser extent, to the affinity of the transporters on the sinusoidal plasma membranes. COMP BIOCHEM PHYSIC),. 113A:2:157-164. 1996.
Journal of lipid research, 1992
We investigated the effects of cholesterol, cholestyramine, and taurocholate feeding on steady state specific activities and mRNA levels of hepatic 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase and cholesterol 7 alpha-hydroxylase in the rat. Interruption of the enterohepatic circulation of bile acids (cholestyramine feeding) increased total HMG-CoA reductase activity 5-fold. Cholesterol and taurocholate administration suppressed total microsomal HMG-CoA reductase activities 87% and 65%, respectively. HMG-CoA reductase mRNA levels increased 3-fold with cholestyramine, did not decrease significantly with cholesterol feeding, but were markedly decreased after taurocholate treatment. Cholesterol 7 alpha-hydroxylase activity increased 4-fold with cholestyramine and 29% during cholesterol feeding, but decreased 64% with taurocholate. Cholesterol 7 alpha-hydroxylase mRNA levels rose 150% and 50% with cholestyramine and cholesterol feeding, respectively, but decreased 73% with taurocholate...
Effect of sodium taurolithocholate on bile flow and bile acid excretion
Journal of Clinical Investigation, 1968
obstruction of segments of the biliary tree by precipitates of sodium taurolithocholate and possibly to a decrease in water entry into the biliary tree during infusion of this bile acid salt. lanoyl taurine; taurodeoxycholic acid, 3a, 12a,-dihydroxy-5p6-cholanoyl taurine; taurocholic acid, 3a, 7a, 12a-trihydroxy-5j3-cholanoyl taurine; taurocholenic acid, 3fthydroxy-5-cholenoyl taurine; muricholic acids, 3a, 6fl, 7atrihydroxy-5#-cholanoic acid, 3a, 6#3, 7fi-trihydroxy-5#cholanoic acid.
Clinical and Experimental Hepatology
Taurine (TAU) is a free amino acid abundant in the human body. Various physiological roles have been attributed to TAU. At the subcellular level, mitochondria are the primary targets for TAU function. Meanwhile, it has been found that TAU depletion is associated with severe pathologies. Cholestasis is a severe clinical complication that can progress to liver fibrosis, cirrhosis, and hepatic failure. Bile duct ligation (BDL) is a reliable model for assessing cholestasis/cirrhosis and related complications. The current study was designed to investigate the effects of cholestasis/cirrhosis on tissue and mitochondrial TAU reservoirs. Cholestatic rats were monitored (14 and 42 days after BDL surgery), and TAU levels were assessed in various tissues and isolated mitochondria. There was a significant decrease in TAU in the brain, heart, liver, kidney, skeletal muscle, intestine, lung, testis, and ovary of the BDL animals (14 and 42 days after surgery). Mitochondrial levels of TAU were also significantly depleted in BDL animals. Tissue and mitochondrial TAU levels in cirrhotic animals (42 days after the BDL operation) were substantially lower than those in the cholestatic rats (14 days after BDL surgery). These data indicate an essential role for tissue and mitochondrial TAU in preventing organ injury induced by cholestasis/cirrhosis and could justify TAU supplementation for therapeutic purposes.
Dietary taurine content changes liver lipids in cats
The Journal of nutrition, 1991
Adult female cats were fed a completely defined purified diet (taurine-free) alone or containing 0.05% taurine (the normal dietary requirement) or 1% taurine (20-fold the normal dietary requirement) for greater than 2 y. The relative composition of conjugated biliary bile acids was not different among the three groups and virtually all bile acids were conjugated with taurine. The taurine concentration in liver varied dramatically with the amount of taurine in the diet. Total liver lipid content decreased with increasing dietary taurine. Individual lipid components also varied, especially free fatty acids (which decreased with increasing dietary taurine) and triglycerides (which increased with increasing dietary taurine), indicating that taurine has a metabolic effect on lipid metabolism. Taurine deficiency also caused significant changes in the fatty acid distribution of sphingomyelin. In particular, a decrease of lignoceric acid and an increase of nervonic acid were observed. The p...