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Results for “BILE ACIDS AND SALTS”

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At least 19 recordsLinked to original sources
PubMed1996

Relationship between stress response toward bile salts, acid and heat treatment in Enterococcus faecalis.

Stress tolerance and cross-protection in Enterococcus faecalis ATCC19433 were examined after exposure to bile salts, acid or heat shock. Bile salts and heat adapted cells demonstrated induced homologous tolerance and cross-resistance. No cross-protection of heat adapted cells against acid stress is observed and pretreatment with bile salts even sensitized the cells to this challenge. Whole-cell protein extract analysis revealed that each treatment induced a battery of stress proteins. Some of these polypeptides are induced by more than one treatment. The greatest overlap is observed between bile salts and heat treatments. Eighteen stress proteins, including DnaK and GroEL, are common between these stresses.

Bile Acids and Salts↗
PubMed1989

Pigment gallstone dissolution in vitro. Solubilization of brown bilirubinate and black polybilirubinate stone material by buffered solvents containing ethylenediaminetetraacetic acid, bile salts, and reducing thiols.

The efficacy of a buffered 1% ethylenediaminetetraacetic acid (EDTA)-2Na solution (pH 9.2) in solubilizing carefully pulverized material from brown bilirubinate and black polybilirubinate pigment stones can be intensified stepwise by admixtures of detergents and mucolytic active thiols. Solubilization effects were quantified either photometrically by measuring the dissolved calcium bilirubinate or gravimetrically by measuring the total weight loss of solids after a defined incubation period. Maximum effects were achieved when using a buffered solvent with 1 g/dl disodium-EDTA, 1 g/dl sodium taurocholate (NaTCA), and 2 g/dl N-acetylcysteine (NAC). Whereas admixtures of NAC enhanced the solubilization of brown bilirubinate stone material additionally by an average of 21.3% (related to the effect of an EDTA/NaTCA-containing solvent), black polybilirubinate material responded rather poorly and inconsistently to NAC (mean, 8.4 +/- 11.7%).

Bile Acids and Salts↗
PubMed1981

[Polyene antibiotic solubilization by bile acid salts in aqueous solutions].

The process of solubilization of polyenic antibiotics, such as amphotericin B, mycoheptin, levorin and nystatin in aqueous solutions of sodium salts of bile acids: desoxycholic, cholic and dehydrocholic was studied. It was shown that amphotericin B and mycoheptin had the highest capacity for solubilization. No solubilization of the antibiotics was observed in the solutions of sodium dehydrocholate. Thermodynamic estimation of the solubilization process with sodium desoxycholate is presented.

Anti-Bacterial Agents↗
PubMed1998

The effect of porcine bile acids on methane production by rumen contents in vitro.

Hindgut fermentation differs from rumen fermentation by a lower methane production and the presence of reductive acetogenesis. Bile acids which are lost into the lower digestive tract may have a promoting effect on reductive acetogenesis in the hindgut. In this experiment it was investigated if bile acids induce reductive acetogenesis in rumen fermentation in vitro. Rumen contents from a fistulated cow were incubated in vitro with ground hay and increasing amounts of porcine bile acids or bile acid salts. Bile acids inhibited methane production up to 70% of the control incubation. The concomitant increase in propionate production compensated for the lower methane production so that the 2H-recoveries were in a normal range between 79-92%. Therefore the occurrence of reductive acetogenesis could be excluded. It is concluded, that bile acids are a controlling factor in caecal methanogenesis.

Animals↗
PubMed1984

Subcellular distribution of bile acids, bile salts, and taurocholate binding sites in rat liver.

We have quantitated bile acids and their conjugates in rat liver using high-pressure liquid chromatography. Over 95% of the hepatic bile acid pool in rat liver homogenates is present as taurocholate and tauromuricholate. Although over 60% of the bile acid pool is recovered in the supernatant, evidence is presented suggesting that taurocholate redistributes among the subcellular fractions during their isolation. Taurocholate (TC) binding to purified subcellular fractions from rat liver was determined by using equilibrium dialysis in a TC concentration range from 0.1 to 100 microM. This is well below the critical micellar concentration of taurocholate (3 mM). All of the fractions investigated exhibited low-affinity binding with dissociation constants from 80 to 240 microM as did membrane lipid vesicles. Therefore, low-affinity binding appears referable to taurocholate nonspecifically partitioning into the lipid bilayer. High-affinity binding is present in plasma membranes, Golgi, and cell supernatant. The high-affinity binding sites in Golgi have a mean dissociation constant (A1) of 1.0 microM and bind 0.15 nmol of TC/mg of protein. Similarly, the high-affinity binding sites of plasma membrane have an A1 of 1.3 microM and bind 0.15 nmol of TC/mg of protein. For cell supernatant, the A1 was 4.8 microM, and 0.35 nmol of TC was bound per mg of protein. Mitochondria, smooth and rough microsomes, and Golgi liposomes showed no detectable amounts of high-affinity binding. These results are compatible with a role for the Golgi complex, cytoplasmic component(s), and plasma membranes in transhepatic bile acid transport.

Animals↗
PubMed1999

Inhibition of protein denaturation by fatty acids, bile salts and other natural substances: a new hypothesis for the mechanism of action of fish oil in rheumatic diseases.

Natural hydrophobic substances like bile salts (cholate, deoxycholate, chenodeoxycholate, lithocholate and their conjugates with glycine and taurine), fatty acids (caprylic, capric, lauric, myristic, palmitic, stearic, oleic, linoleic, arachidonic, eicosapentaenoic and docosahexaenoic acid) were much more active (EC50 approximately 10(-4)-10(-5) M) than selected amino acids (EC50 > 10(-2) M) and inorganic salts (EC50 approximately 10(-1) M) in inhibiting heat-induced denaturation of human serum albumin in vitro. Fish oil, rich in n-3-polyunsaturated acids such as eicosapentaenoic acid and docosahexaenoic acid, administered p.o. (1 ml/kg) in the rat, protected ex vivo (after 2 hr) serum against heat-induced denaturation more than bendazac, a known antidenaturant drug. Thus, we speculated that the antidenaturant activity of fish oil may be partly (in addition to the known effect on endogenous eicosanoid composition) responsible for its beneficial effects in rheumatoid arthritis and other rheumatic conditions. In this connection, it is of note that the in vitro antidenaturant activity of fish oil fatty acids was higher than that of known antidenaturant drugs such as bendazac and bindarit and nonsteroidal anti-inflammatory drugs like phenylbutazone and indomethacin which could exert beneficial effects in chronic inflammatory conditions by stabilizing endogenous proteins.

Administration, Oral↗
PubMed1978

Light-scattering studies on bile acid salts II: pattern of self-association of sodium deoxycholate, sodium taurodeoxycholate, and sodium glycodeoxycholate in aqueous electrolyte solutions.

The pattern of self-association of the bile salts sodium deoxycholate, sodium glycodeoxycholate, and sodium taurodeoxycholate was investigated in aqueous electrolyte solutions by the light-scattering technique. The turbidity of the bile salt solutions was obtained over the concentration range of 0-20 mg/ml at 25 degrees. These data were analyzed according to a monomer-micellar equilibrium model and a stepwise association model. Comparison of the light-scattering data with these models suggests that the monomer-micellar model may be inappropriate. Analysis of the data according to the stepwise association model suggests that the dihydroxy bile salts associate to form dimers, trimers, and tetramers in addition to a larger aggregate which varies in size depending on the degree of conjugation of the bile salt.

Chemical Phenomena↗
PubMed1978

Light-scattering studies on bile acid salts I: Pattern of self-association of sodium cholate, sodium glycocholate, and sodium taurocholate in aqueous electrolyte solutions.

The pattern of association of the trihydroxy bile salts in aqueous electrolyte solutions was investigated utilizing the light-scattering technique. The turbidity of the bile salts sodium cholate, sodium taurocholate, and sodium glycocholate was determined over the concentration range of 0-25 mg/ml at 25 degrees. For sodium cholate, the concentration of the supporting electrolyte was varied from 0.15 to 0.5 M. For all bile salts in 0.15 M electrolyte, the turbidity was determined in sodium fluoride, sodium chloride, sodium bromide, and sodium iodide. Comparison of the light-scattering data with amonomer-micellar model showed that qualitative agreement was obtained; however, quantitative agreement could not be achieved. Further examination of the data showed that the light-scattering results were in good agreement with a model that includes dimers, trimers, and a higher aggregate containing approximately eight monomeric units.

Chemical Phenomena↗
PubMed1978

Vitamin D-3 intestinal absorption in vivo: influence of fatty acids, bile salts, and perfusate pH on absorption.

Intestinal absorption of vitamin D-3 in physiological concentrations was studied in the live unanesthetised rat. In both the jejunum and the ileum a linear relationship was found between the absorption rate of the vitamin and its intraluminal concentration. Increasing the sodium taurocholate concentation in the perfusate above 5mM did not change ileal absorption rate but did decrease jejunal absorption rate. The vitamin's rate of absorption was raised by increases in either the hydrogen ion concentration in vivo is mediated by passive diffusion. The rate of absorption of ttion or the perfusate's flow rate. Addition of 2.5 mM fatty acids of varying chain length and degrees of saturation resulted in a decrease in the rate of vitamin D-3 absorption. These experiments indicate that vitamin D-3 absorption in vivo is mediated by passive diffusion. The rate of absorption of the vitamin is influenced by the composition of the perfusate and the thickness of the unstirred layer.

Animals↗
PubMed1976

Comparison of the binding of various bile acids and bile salts in vitro by several types of fiber.

The binding in vitro of the sodium salts of cholic acid, chenodeoxycholic acid, deoxycholic acid, taurocholic acid, taurochenodeoxycholic acid, taurodeoxycholic acid, glycocholic acid, glycochenodeoxycholic acid, and glycodeoxycholic acid by alfalfa, bran, cellulose, lignin, and cholestyramine was measured. Cholestyramine bound an average of 81.3% of all the bile acids and salts tested whereas cellulose bound only negligible amounts (1.4%). Of the other substances tested, lignin bound 29.2%, alfalfa, 15.9% and bran, 9.0%. No distinct pattern of binding was discerned. It is therefore apparent that the validity of statements concerning the effect of fiber on bile salf metabolism rests upon the specificity of the composition of the fiber involved and the bile acids or salts tested.

Bile Acids and Salts↗
PubMed2000

Cyclooxygenase 2 expression in Barrett's esophagus and adenocarcinoma: Ex vivo induction by bile salts and acid exposure.

BACKGROUND & AIMS: Barrett's esophagus (BE) results from chronic, severe gastroesophageal reflux and predisposes to esophageal adenocarcinoma. Cyclooxygenase (COX)-2 is involved in chronic inflammation and epithelial cell growth. We investigated COX-2 expression in BE and esophageal adenocarcinoma to explore a potential relation between COX-2 expression and metaplasia or carcinogenesis. METHODS: Endoscopic mucosal biopsy specimens of Barrett's intestinal metaplasia (n = 30), Barrett's dysplasia (n = 11), and esophageal adenocarcinoma (n = 5) were compared with normal esophagus (n = 46) and duodenum (n = 46) and analyzed by Western blotting and immunohistochemistry. RESULTS: Immunoblots revealed constitutive expression of COX-2 in normal esophagus and duodenum. COX-2 protein expression was significantly higher in patients with Barrett's metaplasia, dysplasia, and adenocarcinoma compared with normal squamous esophageal or columnar duodenal epithelia and was heterogenous in different regions of the BE surface. Immunohistochemistry revealed prominent staining in the glands of BE, dysplasia, and adenocarcinoma and faint staining in the basal layers of squamous esophagus and the surface of the duodenum. In response to pulses of acid or bile salts in an ex vivo organ culture system, COX-2 expression increased significantly in BE tissues, and this effect was attenuated by the selective COX-2 inhibitor NS-398. CONCLUSIONS: The results show COX-2 expression in normal esophagus, which increases significantly in BE and esophageal adenocarcinoma. COX-2 is regulated ex vivo by exposure to acid or bile salts.

Acids↗
PubMed1997

Evidence of distinct amino acid and bile salt receptors in the olfactory system of the zebrafish, Danio rerio.

The molecular receptors for amino acid and bile salt odorants of adult zebrafish, Danio rerio, were partially characterized using electro-olfactogram recording methods. Each of the 14 odorants tested interact with partially independent odorant receptor(s). Based on shared patterns of adaptation, cluster analysis identified two very dissimilar groups of odorants. The first group comprised the 8 amino acids with subgroups of basic, acidic and neutral amino acids. The second group comprised the 6 bile salts with subgroups of non-conjugated, taurine- and glycine-conjugated bile salts. Comparison of the general patterns of partial adaptation of amino acid and bile salt odorants suggests fundamental differences in their odorant receptors. Presumably, the differences in the extent of partial adaptation are due to differences in the transduction cascades activated or the distribution of odorant receptors on individual olfactory receptor neurons.

Animals↗
PubMed1991

Isolation and identification of bile salts conjugated with cysteinolic acid from bile of the red seabream, Pagrosomus major.

Bile salts present in gallbladder of wild and cultured red seabream, Pagrosomus major, a marine teleost were analyzed. The bile from wild red seabream was found to contain two previously unknown bile salts along with two known bile salts, taurocholate and taurochenodeoxycholate. Isolation of each bile salt was performed by column chromatography. Fast atom bombardment mass spectra of the unknown bile salts showed the molecular ions (M-H)- of m/z 544 and 528 which are shifted 30 mass units upfield compared to those (m/z 514 and 498) of taurocholate and taurochendeoxycholate, respectively; this is consistent with the presence of cysteinolic acid (mol wt 155) instead of taurine (mol wt 125). Enzymatic hydrolysis of the bile salts released cholic acid and chenodeoxycholic acid, respectively, and an amino acid that was identified as D-cysteinolic acid by direct comparison with an authentic sample. From these results, the bile salts in the bile of wild red seabream were identified as the conjugates of cholic acid and chenodeoxycholic acid with cysteinolic acid. 1H- and 13C-magnetic resonance spectra of the bile salts were also consistent with the proposed structure. The cysteinolic acid conjugates were found only in wild and not in cultured red seabream; this distinction seems to result from differences in dietary cysteinolic acid.

Animals↗