PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Taurochenodeoxycholic Acid”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1996

[Intrahepatic cholestasis].

Various effects of cholestatic drugs, bile acids, and estrogens on the hepatocyte plasma membranes, as well as their changes in the cholestatic diseases are briefly reviewed. Cyclosporin A inhibits bile salt transporter (BST) on the canalicular membrane (CM). Ethynylestradiol reduces canalicular glutathione excretion. Estradiol-17beta-D-glucuronide interacts with MDR1, and taurochenodeoxycholic acid and lithocholate-3-O-glucuronide may interact with vesicular transport system, each of which may relate with the genesis of cholestasis. In Byler disease, biliary chenodeoxycholic acid excretion is defective. Lipopolysaccharide decreases the function of canalicular multispesific organic anion transporter (MOAT) which seems the first step in septic cholestasis. Obstructive jaundice causes reduced activity of both canalicular BST and MOAT. The mechanisms of choleretic action of S-adenosylmethionine and other drugs are also reviewed.

Animals↗
PubMed1994

Oral S-adenosyl-L-methionine (SAMe) administration enhances bile salt conjugation with taurine in patients with liver cirrhosis.

We investigated whether the oral administration of SAMe influences the hepatic availability of sulphur amino acids and the extent of bile salt amidation with taurine in liver cirrhosis. Ten patients with cirrhosis (eight Child-Pugh A and 2 B, aged 48-65 years), were studied before and 2 months after oral SAMe administration (800 mg per day). Bile was obtained using a string-test device (Entero-test), after gall-bladder contraction with caerulein. No significant changes were found in the per cent composition of biliary amino acids, except for an increase in glutamic acid (from 3.7 +/- 0.6% before to 6.1 +/- 1.1% after SAMe, p = 0.003) and taurine from 2.2 +/- 2.3% (range 0.4-6.8) to 7.2 +/- 9.2% (range 0.5-28.1), (NS). HPLC analysis showed a trend towards increased per cent tauroconjugation of all individual bile salts, with a significant rise in taurochenodeoxycholic acid (from 15.0 +/- 9.4% to 25.3 +/- 9.7%, p = 0.05) and a drop in glycocholic acid (from 39.1 +/- 15.3% to 25.3 +/- 9.8%, p = 0.05). These data suggest that in the cirrhotic liver exogenous SAMe is partially metabolized to taurine, which is used for bile salt amidation.

Administration, Oral↗
PubMed1994

Expression and characterization of a functional rat liver Na+ bile acid cotransport system in COS-7 cells.

A cDNA for the rat liver sodium-dependent bile acid cotransporter was expressed in COS-7 cells to study the functional properties of the translated protein in a mammalian cell line. A 1.2-kb insert was ligated into a pMAMneo vector and transiently transfected using electroporation. After optimal conditions were established, the transiently transfected COS cells were screened with fluorescent-conjugated labeled bile acids for evidence of expression of the cotransporter after 48 h. The uptake of [3H]taurocholate ([3H]TC) was then determined in cells transfected with or without the bile acid insert. Progressive uptake of [3H]TC (0.45 microM) was observed for 30 min in the presence of sodium. In contrast, no uptake of [3H]TC was observed in the absence of sodium, in nontransfected COS cells, or in COS cells transfected with the empty plasmid. Kinetic studies revealed a Michaelis constant (Km) of 29 microM, essentially identical to the Km of this cotransporter described in intact rat hepatocytes and membrane vesicles. Uptake of [3H]TC (5.0 microM) at 5 min (n = 3-6) was inhibited by 100 microM taurochenodeoxycholic acid (81%), tauroursodeoxycholic acid (77%), cholic acid (55%), chenodeoxycholic acid (74%), and ursodeoxycholic acid (56%) but not by 100 microM taurodehydrocholate, 1 mM probenecid, or 100 microM bilirubin. In contrast, bumetanide (500 microM) inhibited [3H]TC uptake by 52%. These studies indicate that the isolated cDNA codes for a physiological bile acid transporter present in rat hepatocytes and that posttranslational factors present in mammalian cells may not be as important in defining properties of this cotransport system.

Animals↗
PubMed1996

Peroxidase activity of liver microsomal vitamin D 25-hydroxylase and cytochrome P450 1A2 catalyzes 25-hydroxylation of vitamin D3 and oxidation of dopamine to aminochrome.

Purified liver microsomal vitamin D 25-hydroxylase, a cytochrome P450, catalyzes 25-hydroxylation of vitamin D3 in the absence of NADPH and NADPH-cytochrome P450 reductase by using t-butyl hydroperoxide as electron donors. The rate of 25-hydroxylation was approximately the same when NADPH/ NADPH-cytochrome P450 reductase or t-butyl hydroperoxide was used as electron donor. The Km value for vitamin D3 in the presence of t-butyl hydroperoxide was found to be 30 microM. The rates of 25-hydroxylation of 1 alpha-hydroxyvitamin D3 and 5 beta-cholestane-3 alpha, 7 alpha-diol catalyzed by 25-hydroxylase were significantly higher when the reaction proceeded in the presence of NADPH/NADPH-cytochrome P450 reductase than in the presence of t-butyl hydroperoxide. Other liver microsomal cytochrome P450 forms such as taurochenodeoxycholic acid 6 alpha-hydroxylase and cytochromes P450 1A2 and 2B4 did not catalyze 25-hydroxylation of vitamin D3 in the presence of NADPH/NADPH-cytochrome P450 reductase or t-butyl hydroperoxide. The peroxidase activity of the 25-hydroxylase also catalyzed oxidation of dopamine to aminochrome. A linear correlation between increase in aminochrome formation and increase in the amount of 25-hydroxylase was observed in the oxidation of dopamine. The Km values for dopamine and t-butyl hydroperoxide were 8.6 microM and 1 mM when 25-hydroxylase catalyzes the formation of aminochrome in the presence of t-butyl hydroperoxide. Oxidation of dopamine to aminochrome catalyzed by the peroxidase activity of cytochrome P-450 1A2 was observed in the presence of t-butyl hydroperoxide. A linear correlation between formation of aminochrome and the amount of cytochrome P450 1A2 was found.

Animals↗
PubMed1997

The 3'-untranslated region of the mouse cholesterol 7alpha-hydroxylase mRNA contains elements responsive to post-transcriptional regulation by bile acids.

To investigate the importance of the 3'-untranslated region (UTR) of the mouse cholesterol 7alpha-hydroxylase (cyp7) mRNA in post-transcriptional regulation of expression of the cyp7 gene, chimaeric genes encoding mRNA containing the structural sequence of chloramphenicol acetyltransferase (CAT) linked to either the 3'-UTR of the mouse cyp7 mRNA or the SV40 early gene mRNA were constructed. The human cytomegalovirus (CMV) promoter was used to drive the expression of all the chimaeric genes. Thus the transgenes had identical sequences in the promoter, the regions encoding the 5'-UTR and translated sequence but differed in the region encoding the 3'-UTR of their respective mRNA species. The transgene containing the entire cyp7 3'-UTR (designated CMV.CAT.CYP7) gave rise to CAT activity in transfected hepatoma cells that was one-quarter of that obtained in cells transfected with the transgene containing the SV40 3'-UTR (designated CMV.CAT.SV40). The 3'-UTR of the cyp7 mRNA contains sequences resembling AU-rich elements (AREs). Deleting eight of nine putative AREs from the CYP7 3'-UTR sequence increased the CAT activity to a level greater than that observed for CMV.CAT. SV40, whereas deletion of the intron region had no effect. These results show that the AREs of the 3'-UTR of the cyp7 mRNA decrease transgene expression. Bile acids are known to repress the expression of the cyp7 gene. To test whether the 3'-UTR of the cyp7 mRNA has a role in this process, the expression of the chimaeric genes was evaluated in hepatoma cells competent for bile acid uptake. Conjugated bile acids, but not unconjugated bile acids, further decreased the expression of the CMV.CAT.CYP7 transgene. The same bile acids had no effect on the expression of the CMV.CAT.SV40 transgene. Deletion of the intron from the cyp7 sequence did not alter the CAT activity compared with the parental plasmid, and also did not alter the sensitivity of the transgene to the conjugated bile acids. Deletion of the AREs from the cyp7 3'-UTR, which increased the expression of the transgene, did not abolish the sensitivity of the transgene to repression by conjugated bile acids. Thus the 3'-UTR of the mouse cyp7 mRNA also contains elements that facilitate the further repression of transgene expression in the presence of conjugated bile acids. The results indicate that the 3'-UTR of the mouse cyp7 mRNA contains information specifying regulation at the post-transcriptional level.

Animals↗
PubMed2006

Relationship of dietary antimicrobial drug administration with broiler performance, decreased population levels of Lactobacillus salivarius, and reduced bile salt deconjugation in the ileum of broiler chickens.

Straight-run broiler chickens were raised either in floor pens or wire-floored cages (trial 1) or in floor pens only (trials 2, 3, and 4). Birds raised in floor pens had lower BW and feed intakes than those raised in cages. The administration of bacitracin in the feed increased feed intake from d 12 to d 35, decreased the feed conversion ratio during the same period in trial 2, and improved the weight gain of broilers from d 0 to 10 in trial 3. The concentrations of conjugated bile salts (taurocholic and taurochenodeoxycholic acids) were higher in the ileal contents of broilers administered the antimicrobials compared with untreated birds. Supplementation of the feed with monensin increased fat digestibility in the ileum of the birds. Although total numbers of bacteria in ileal contents were the same regardless of whether antimicrobials were administered or not, the bacterial community differed qualitatively. Populations of Lactobacillus salivarius were reduced in birds fed antimicrobials relative to untreated broilers. A representative ileal isolate of L. salivarius deconjugated bile salts in pure culture in the laboratory and in the ileal contents of ex-Lactobacillus-free chickens maintained in a protective environment and colonized by the Lactobacillus isolate. These observations provide a link between bile salt deconjugation in the ileum by L. salivarius and decreased weight gain of broilers. Lactobacillus salivarius populations could be targeted in future studies aimed at modification of the ileal bacterial community to achieve growth promotion of broilers without the administration of antimicrobial drugs.

Animal Feed↗
PubMed1989

Development of a differential medium for bile salt hydrolase-active Lactobacillus spp.

An agar plate assay was developed to detect bile salt hydrolase activity in lactobacilli. On Lactobacillus-selective MRS or Rogosa SL medium supplemented with taurodeoxycholic, taurocholic, or taurochenodeoxycholic acids, bile salt hydrolysis was manifested at two intensities: (i) the formation of precipitate halos around colonies or (ii) the formation of opaque granular white colonies. Sixty-six lactobacilli were tested for bile salt hydrolase activity by both the plate assay and a sensitive radiochemical assay. No false-positive or false-negative results were detected by the plate assay. Based on results of experiments with Eubacterium lentum and Bacteroides species, the plate assay was dependent on two factors: (i) the presence of bile salt hydrolytic activity and (ii) the ability of the organism to sufficiently acidify the medium to protonate free bile acids. The availability of a differential medium for determination of bile salt hydrolase activity will provide a rapid method for determining shifts in a specific functional activity of intestinal Lactobacillus species and provide a rapid screening capability for identifying bile salt hydrolase-deficient mutants. The latter application should allow bile salt hydrolase activity to be used as a marker enzyme in genetic experiments.

Amidohydrolases↗
PubMed1975

Neural organization of esophageal peristalsis: role of vagus nerve.

The purpose of this investigation was 2-fold: first, to determine the velocity of peristalsis in the smooth muscle area of opossum esophagus before and after administration of atropine; second, to evaluate the role of the vagus nerves in the control of the propagative nature of esophageal peristalsis. Intraluminal pressures were measured through a pressure transducer recorder system attached to continuously perfused catheters. The velocity of peristalsis in the lower third of the esophagus progressively decreased from 3.25 plus or minus 0.20 (SE) cm per sec at the 70 to 80% level to 2.17 plus or minus 0.14 (SE) at the 80 to 90%level to 1.83 plus or minus 0.10 (SE) at the 90 to 100% level. After administration of intraperitoneal atropine (100 mug per kg), the velocities were 3.1 plus or minus 0.26 (SE) cm per sec, 2.38 plus or minus 0.22 (SE), and 1.74 plus or minus 0.10 (SE), respectively, at the 70 to 80%, 80 to 90%, and 90 to 100% levels. The changes were not statistically significant. Electrical stimulation of the distal cut end of the vagus nerve induced peristaltic contractions. The velocities of peristalsis after electrical stimulation of the vagus nerve were 3.24 plus or minus 0.72 (SE) cm per sec, 2.81 plus or minus 0.64 (SE), and 1.84 plus or minus 0.34 (SE), respectively, at the 70 to 80%, 80 to 90%, and 90 to 100% levels. Results of this study indicate that the velocity of peristalsis in the smooth muscle area of the opossum esophagus has a caudally decreasing gradient. Bilateral cervical vagotomy and stimulation of the distal cut end initiates peristaltic contraction indicating that the propagative nature of peristalsis in the smooth musurrent, does not alter mucosal cyclic AMP. Dibutyryl cyclic AMP decreased net sodium absorption and increased short circuit current; findings which were qualitatively identical to those produced by taurochenodeoxycholic acid. These studies support the proposal that bile salts stimulate colonic electrolyte secretion by increasing mucosal cyclic AMP.

Animals↗
PubMed1981

Thin-layer chromatographic separation of conjugates of ursodeoxycholic acid from those of litho-, chenodeoxy-, deoxy-, and cholic acids.

Separation of the glycine and taurine conjugates of ursodeoxycholic acid from those of lithocholic acid, chenodeoxycholic acid, deoxycholic acid, and cholic acid by thin-layer chromatography is described. Thus, on running a silica gel G plate first in a solvent system of n-butanol-water 20:3 and then in a second solvent system of chloroform-isopropanol-acetic acid-water 30:20:4:1, all the above-mentioned conjugated bile acids are separated from one another. The application of this method to study the change in the biliary bile acid conjugation pattern in ursodeoxycholic acid-fed gallstone patients is described.

Chenodeoxycholic Acid↗
PubMed2005

Effect of tibolone on turnover of cholesterol to bile acids in ovariectomized rats.

OBJECTIVE: Tibolone is used in breast cancer therapy in women. The most important aspect of this therapy concerns its influence on bone and lipid metabolism. Several studies have reported the effect of tibolone on plasma lipids. Approximately 40% of total cholesterol removal occurs by its conversion to bile acids, a process that takes place in the liver. The aim of the study was to evaluate the influence of tibolone on the conversion of cholesterol to bile acids in estrogen-deficient rats. DESIGN: Thirty female Wistar rats were divided into three groups: sham-operated controls, ovariectomized controls, and ovariectomized rats treated with tibolone. After 42 days of drug administration, bile was collected under anesthesia after administration of radioactive 4-C cholesterol. Bile was assayed for total C radioactivity; C bile acids were determined after thin-layer chromatography separation by using the isotopic technique. RESULTS: The ovariectomy decreased the concentrations of C-radioactive bile, taurocholic acid, and cholic acid. The administration of tibolone significantly increased the excretion of C-radioactive bile and C-radioactive bile acids as compared with ovariectomized controls. Moreover, the therapy with tibolone significantly increased the concentrations of C taurocholic acid, C glycocholic acid, cholic acid, and taurochenodeoxycholic plus taurodeoxycholic acids. CONCLUSION: The results of the present study suggest that tibolone may increase the concentrations of cholesterol and trihydroxy bile acids in bile. These changes may be associated with an increased risk of gallstone generation.

Animals↗
PubMed1973

Regulatory effects of dietary sterols and bile acids on rat intestinal HMG CoA reductase.

The specific activity (concentration) of microsomal HMG CoA reductase of intestinal crypt cells was studied in rats fed sterols and bile acids, either singly or in combination. It was found that the basal activity of the reductase was not suppressed by the administration of relatively large amounts of bile acid (taurocholate or taurochenodeoxycholate). Bile acids reduced the specific activity of the reductase only in rats in which the activity of the enzyme had first been enhanced by biliary diversion or by sitosterol feeding. In addition, bile acid feeding abolished the diurnal elevation of reductase activity that normally occurs between midnight and 2 a.m. In no case did bile acids reduce enzyme activity below basal levels. A pronounced (60%) reduction of intestinal HMG CoA reductase activity was observed in rats fed cholesterol and bile acid in combination. This reduction in activity could not be ascribed to an increase in intestinal bile acid flux but was associated with an increase in sterol concentration within the intestinal crypt cells. These results indicate that dietary sterols and bile acids both play a role in the regulation of intestinal HMG CoA reductase.

Alcohol Oxidoreductases↗
PubMed1979

High performance liquid-chromatographic analysis of individual bile acids: free, glycine- and taurine-conjugated bile acids.

High performance liquid-chromatographic analyses of individual bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, and lithocholic acid), free and conjugated with glycine and taurine, are described. The analyses of free and glycine-conjugated bile acids are based on esterification of carboxyl group of bile acids with O-(p-nitrobenzyl)-N, N'-diisopropylisourea (PNBDI). Moreover, ursodeoxycholic acid, hyocholic acid, hyodeoxycholic acid and 3beta-hydroxy-5-cholenoic acid also are able to analyse by this method. These bile acids in biological sample were extracted by an Amberlite XAD-2 column, and separated by DEAE-Sepharose CL-6B into free, glycine- and taurine-conjugated bile acids. After the separation, free and glycine-conjugated bile acids were esterified with PNBDI directly. Because taurine-conjugated bile acids are unable to be esterified with PNBDI, these bile acids were hydrolyzed by NaOH in order to make free bile acids, and then they were esterified. Because the p-nitrobenzyl ester of bile acids has characteristic ultraviolet absorption, these compounds were separated to individual bile acids by high performance liquid-chromatography, and detected by an UV-detector. An analysis of individual bile acids in human bile was demonstrated.

Bile Acids and Salts↗
PubMed1994

High concentrations of conjugated bile acids inhibit bacterial growth of Clostridium perfringens and induce its extracellular cholylglycine hydrolase.

To investigate the effects of conjugated bile acid on bacterial growth and cholylglycine hydrolase activity, Clostridium perfringens from human feces was exposed to varying concentrations of taurine- or glycine-conjugated chenodeoxycholic acid. Extracellular enzyme activity was determined by deconjugation of radiolabeled taurocholic acid and viable cells were counted after anaerobic culture at 37 degrees C for 24 h. Viable cells were decreased with more than 1.0 mg of conjugated chenodeoxycholic acid per mL and there were no viable cells with 10.0 mg of bile acid per mL. Although total enzyme activity was decreased according to the bile acid concentration, enzyme activity per bacterium was increased between 1.0 and 4.0 mg/mL. There were no statistically significant differences between the types of conjugation. It was concluded that conjugated bile acids may exert inhibitory effect on bacterial growth and extracellular cholylglycine hydrolase activity in Clostridium perfringens. However, under the physiologic condition in the human intestine, conjugated bile acid might induce production of extracellular cholyglycine hydrolase per bacterium.

Amidohydrolases↗
PubMed1992

Bile salt/acid induction of DNA damage in bacterial cells: effect of taurine conjugation.

Bile salts and acids have been implicated in the etiology of colon cancer, possibly through their ability to cause DNA damage. Taurine-conjugated and nonconjugated forms of three bile salts and one bile acid were tested for DNA repair-inducing potential and for cellular toxicity in a recently developed Escherichia coli chromotest system. The taurine-conjugated forms of sodium deoxycholate and lithocholic acid had reduced ability to induce DNA repair. Also the taurine-conjugated form of lithocholic acid had a reduced lethal effect. These observations suggest that the biotransformation step, whereby bacteria in the intestine remove the taurine added to bile salts in the liver, may be significant in the etiology of colon cancer.

Bile Acids and Salts↗
PubMed1974

Effects of oleic and ricinoleic acids on net jejunal water and electrolyte movement. Perfusion studies in man.

To examine the effects of oleic acid and ricinoleic acid on jejunal absorption, steady-state jejunal perfusions were performed in healthy volunteers. Taurocholate, used to solubilize the fatty acids, did not influence absorption. Both fatty acids (concentration, 10 mM) reversed electrolyte and water net movement; that is, they induced fluid secretion; this effect was rapidly reversible. Ricinoleic acid (the active principle of castor oil) was the more potent, producing fluid secretion when perfused at concentrations at which oleic acid was without effect. However, ricinoleic acid was absorbed more slowly than was oleic acid, and hence was associated with higher intraluminal concentrations. Addition of lecithin and monoolein did not diminish the secretory effect of ricinoleic acid; addition of a secretory bile acid (taurodeoxycholate) did not enhance the effect. The response of the jejunal mucosa to a known cathartic provides observations pertinent to the pathophysiology of steatorrheal diseases in man. Dietary fatty acid also has secretory properties with respect to the human intestine; bacterial hydration, to hydroxy fatty acids, is not required to induce fluid secretion.

Body Water↗