Concentration Of Cholic Acid Research Articles

Chenodeoxycholic Acid and Deoxycholic Acid Inhibit 11β-Hydroxysteroid Dehydrogenase Type 2 and Cause Cortisol-induced Transcriptional Activation of the Mineralocorticoid Receptor

Inappropriate activation of the mineralocorticoid receptor (MR) results in renal sodium retention and potassium loss in patients with liver cirrhosis. Recent evidence suggested that this MR activation is, at least in part, a result of bile acid-dependent reduction in 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta HSD2) activity, an enzyme preventing cortisol-dependent activation of MR by converting cortisol to cortisone. Here, we investigated the molecular mechanisms underlying bile acid-mediated MR activation. Analysis of urinary bile acids from 12 patients with biliary obstruction revealed highly elevated concentrations of chenodeoxycholic acid (CDCA), cholic acid (CA), and deoxycholic acid (DCA), with average concentrations of 50-80 microm. Although CDCA and DCA both mediated nuclear translocation of MR in the absence of 11 beta HSD2 and steroids in transiently expressing HEK-293 cells, the transcriptional activity of MR was not stimulated. In contrast, CDCA and DCA both inhibited 11 beta HSD2 with IC(50) values of 22 and 38 microm, respectively and caused cortisol-dependent nuclear translocation and increased transcriptional activity of MR. LCA, the bile acid that most efficiently inhibited 11 beta HSD2, was present at very low concentrations in cholestatic patients, whereas the weak inhibitor CA did not cause MR activation. In conclusion, these findings indicate that CDCA, and to a lesser extent DCA, by inhibiting 11 beta HSD2, mediate cortisol-dependent nuclear translocation and transcriptional activation of MR and are responsible at least for a part of the sodium retention and potassium excretion observed in patients with biliary obstruction.

Alterations in intestinal microflora, faecal bile acids and short chain fatty acids in dextran sulphate sodium-induced experimental acute colitis in rats.

The physiological effects on faecal bile acids and short chain fatty acids (SCFAs) or intestinal microflora in dextran sulphate sodium (DSS)-induced colitis remain unknown and are an area of interest DESIGN ALTERATIONS: of these parameters in DSS-induced colitis in rats were evaluated. Male Sprague-Dawley rats (n = 10) were given a 3% DSS aqueous solution orally for 7 days. The concentrations of bile acids and SCFAs in the faeces were measured using gas chromatography and high-performance liquid chromatography. Intestinal microflora, especially anaerobes, were investigated by microbiological methods. On day 7, the concentrations of lithocholic acid and alpha-muricholic acid were significantly decreased and that of cholic acid was significantly increased. There was a strong correlation between the concentration of cholic acid and the macroscopic area of damaged tissue in the colon (R = 0.74, P < 0.05). With respect to SCFAs, DSS administration significantly decreased the concentrations of acetic acid and n-butyric acid. There was also some correlation between the concentration of acetic acid and macroscopic damaged area in the colon (R = -0.60, P = 0.07). Bacteriological studies revealed significantly decreased eubacteria, bifidobacteria and total anaerobes after the administration of DSS. In contrast, lactobacilli were significantly increased. With the progression of DSS-induced colitis, faecal bile acids, SCFAs and intestinal microflora were altered. It is possible that these alterations contribute in part to the progression of DSS-induced colitis.

Enhancement of endothelial nitric oxide production by chenodeoxycholic acids in patients with hepatobiliary diseases.

The purpose of this study was to clarify whether physiological concentrations of bile acids could affect endothelial nitric oxide production. We investigated the relationships between clinical concentrations of individual bile acids observed in patients with hepatobiliary diseases and endothelial nitric oxide production induced by each bile acid. Fifteen serum bile acids were measured using high-performance liquid chromatography combined with enzymatic fluorometry in 8 patients with liver cirrhosis, obstructive jaundice, and 8 healthy subjects. The effects of individual bile acids on nitric oxide production were examined in human umbilical endothelial cells by measuring the concentration of NO2- in the cultured medium. NO release in the blood was also determined by measuring the NO2-/NO3- concentration in these patients. In patients with hepatobiliary diseases, the plasma concentrations of chenodeoxycholic acid, ursodeoxycholic acid and cholic acid (free acid, taurine and glycine conjugates) were markedly elevated. Incubation of cells with chenodeoxycholic acid and deoxycholic acid (free acid, taurine and glycine conjugates) enhanced NO2- production in a concentration-dependent manner, while cholic acid (free and its conjugates) did not. The effects of individual bile acids on nitric oxide production were additive. Patients with liver cirrhosis and obstructive jaundice had higher plasma levels of NO2-/NO3- levels than the control subjects. These results suggest that increased plasma concentrations of chenodeoxycholic acid (free, taurine and glycine conjugates) in patients with hepatobiliary diseases may induce endothelial nitric oxide production. Thus, nitric oxide production induced by bile acids may be involved in the pathogenesis of circulatory abnormalities in patients with liver diseases.

Gastric Stump Cancer

Purpose: Gastric stump cancer is defined as a cancer that develops in the stomach after a resection in cases of non-malignant or malignant gastric disease. The interval between the gastrectomy and the detection of gastric stump cancer must be over 5 years. Since duodenogastric reflux gastritis is a precancerous condition and one of the most important factors inducing gastric stump cancer, we compared the bile-acid content of gastric juice between gastric stump cancer patients and controls. Materials and Methods: To evaluate retrospectively the surgical treatment of patients with gastric stump cancer, we reviewed the cases histories of 1016 stomach cancer patients who had been operated on at the Department of General Surgery, Kosin University Gospel Hospital, between 1995 and 1998. The gastric juice was collected during the operations on the gastric stump cancer patients by using a needle puncture of the fundus of the stomach and during the endoscopic examinations of the control subjects. The samples were analyzed for various bile acids (gas chromatography/mass spectrometry). Results: The 6 gastric stump cancer cases accounted for of all gastric cancer patients; 5 patients were first operated on for a peptic ulcer and the remaining one for an adenocarcinoma of the stomach. All of the cases were men. The reconstruction method after the initial gastrectomy was a Billroth II in all cases. The sites of the gastric stump cancer were the anastomotic sitein 2 patients, the upper body in 2, the fundus in 1 and the cardia in 1. The operative methods were 3 total gastrectomies, 2 subtotal gastrectomies with Roux en Y anastomosis, and 1 partial gastrectomy with lymph node dissection and had a curative intention in all patients. All of the patients were still surviving at the time of this report. The gastric juices of 4 gastric stump patients showed significantly higher contents of cholic acid () compared to the gastric juices of 35 control subjects ()(p). Chenodeoxycholic acid and lithocholic acid were not significantly different. Conclusion: The gastric juice of gastric stump cancer patients contained a significantly higher cholic acid content. At the time of the initial gastrectomy, an operative method that prevents duodenogastric reflux may prevent or minimize the development of gastric stump cancer, and more aggressive surgical treatment may improve survival.

Effects of consumption of white bread and brown bread on the concentrations of fecal bile acids and neutral steroids and on fecal enzyme activities

The effects of consumption of white bread (low fiber) and brown bread (high fiber) on the fecal excretions of bile acids and neutral steroids and on fecal enzyme activities were assessed in ten healthy males (mean age 27 years). The study subjects included in their normal diet for one-week period in turn, white bread and brown bread (230–320 g/d). Fecal samples were collected at the two final consecutive days of each study week period. The daily fecal output was significantly higher, the concentration of cholic acid in feces significantly decreased by approx. 29% and a tendency for lower concentrations of other bile acids and neutral steroids occurred during consumption of brown bread compared to those during consumption of white bread. Also, the fecal enzyme activities of β-glucosidase and β-glucuronidase significantly decreased during the same period, while those of urease and tryptophanase remained unchanged. The lower concentration of cholic acid and decreased enzyme activities of β-glucosidase and β-glucuronidase are indications of positive effects of consumption of brown bread.

Bile acid patterns in meconium are influenced by cholestasis of pregnancy and not altered by ursodeoxycholic acid treatment

BACKGROUNDData on meconium bile acid composition in newborn babies of patients with intrahepatic cholestasis of pregnancy (ICP) are relatively scant, and changes that occur on ursodeoxycholic acid (UDCA) administration have...

Bile acid concentrations, cytotoxicity, and pH of fecal water from patients with colorectal adenomas.

In the multistage model of human colorectal tumorigenesis, both genetic and environmental factors play an important role. The identity of the environmental factors involved, however, still remains to be elucidated. As fecal bile acids are proposed as candidates, we compared the concentration of bile acids in fecal water from patients at different risk of developing colorectal cancer. In addition, pH of fecal water as well as its cytotoxicity to HT-29 colonic cells was determined. The high-risk group consisted of individuals diagnosed with one or more (tubulo)villous colorectal adenomas larger than 1 cm in diameter and containing moderate or severe dysplasia (N = 20). Subjects with colorectal adenomas smaller than 1 cm and showing only minor dysplasia were assigned to the medium risk group (N = 19). The control group consisted of persons with normal findings by colonoscopy (N = 25). The results show no significant differences in fecal water bile acid concentrations between the three groups. However, 46% of the observed cytotoxicity is explained in a regression model that includes pH and the concentrations of deoxycholic acid, cholic acid, and ursodeoxycholic acid. The pH of fecal water is found to be significantly lower in the high risk group as compared to the controls, suggesting that a relatively high fecal pH has a protective effect on the development of colorectal adenomas. Although hyperproliferation as a result of cytotoxicity has been suggested to contribute to tumor formation in the colon, the pH-dependent cytotoxicity of bile acids in fecal water was not found to be associated with adenoma formation in the present study.

Studies of cholesterol and bile acid metabolism, and early atherogenesis in hamsters fed GT16-239, a novel bile acid sequestrant (BAS)

The purpose of this study was to compare the efficacy of GT16-239, an alkylated, cross-linked poly(allylamine) bile acid sequestrant with cholestyramine on cholesterol and bile acid metabolism, and early aortic atherosclerosis in hypercholesterolemic male F1B Golden Syrian hamsters. In this controlled study, 42 hamsters were divided into six groups and were fed a chow-based hypercholesterolemic diet supplemented with a 10% oil blend (55% coconut/45% corn), 0.1% cholesterol (w/w) (control) and either 0.9 or 1.2% cholestyramine or 0.2, 0.4 or 0.6% GT16-239 for 13 weeks. Laboratory analyses included evaluating plasma lipoprotein cholesterol and triglyceride concentrations, hepatic HMG-CoA reductase and 7 α-hydroxylase activities, fecal excretion of bile acids and neutral sterols, hepatic cholesterol concentrations, and early atherosclerosis (aortic fatty streak area). Relative to the control diet, the 0.6% GT16-239 versus the 1.2% cholestyramine significantly inhibited the elevation of plasma lipoprotein total cholesterol (TC) (−69% vs −40%), high density lipoprotein-cholesterol (HDL-C) (−49% vs −30%), and non-HDL-C (−81% vs −48%) concentrations; increased the activities of both HMG-CoA reductase (1492% vs 62%) and 7 α-hydroxylase (175% vs 86%); lowered the concentration of hepatic cholesteryl ester (−94% vs −59%); increased fecal cholesterol concentration (+28% vs −10%); and decreased aortic fatty streak area (−100% vs −86%). Unexpected findings of this comparison were increased fecal concentrations of cholic acid (533%) and chenodeoxycholic acid (400%) and the reduction in lithocholic acid (−50%) in the 0.6% GT16-239 compared to the 1.2% cholestyramine group. In summary, GT16-239 had a greater impact on cholesterol metabolism and early atherosclerosis in hypercholesterolemic hamsters than cholestyramine.

Relevance of serum bile acid profile in the diagnosis of intrahepatic cholestasis of pregnancy in an high incidence area: Portugal

Objective(s): The present work was conducted to clarify the relevance of usual liver function tests, and define the most predictive serum bile acid profile for diagnosis of intrahepatic cholestasis of pregnancy (ICP). Study design: This study comprised 20 healthy nonpregnant women and 77 pregnant women in the last trimester of pregnancy, from which 38 were normal pregnancies, and 39 suffered from ICP. Liver function tests were evaluated by routine laboratory techniques, conjugated bile acids were analysed by high-performance liquid chromatography, and unconjugated forms were measured by an enzymatic–fluorimetric assay. Results: During the third trimester in normal pregnancy, increased concentration of conjugated species affected all primary bile acids, although only significantly for glycocholic acid. Moreover, deoxycholic acid proportion decreased when compared with healthy nonpregnant women. Important ICP-induced changes in serum profiles of amidated bile acids were observed, involving both a marked increase in cholic acid concentration and a shift towards a higher proportion of taurine-conjugated species. Among routine liver tests, alanine aminotransferase and conjugated bilirubin were the most common indicators of ICP. Conclusion(s): In the early diagnosis and follow-up of ICP, the most predictive and accurate markers (efficiency 100%) were: (i) TBA concentration in serum >11.0 μmol l −1: (ii) cholic/chenodeoxycholic acid ratio >1.5 and cholic acid percentage >42%: (iii) glycine/taurine bile acid ratio <1.0 or glycocholic acid concentration >2.0 μmol l −1. Accurate diagnosis based on sensitive biochemical markers followed by appropriate treatment may improve both pregnancy outcome and newborn prognosis.

The hypocholesterolemic and antiatherogenic effects of chiolazol H, a chemically functionalized insoluble fiber with bile acid sequestrand properties in hamsters

Cholazol H (Alpha-Beta Technology, Worcester, MA), a chemically functionalized, insoluble dietary fiber with bile acid sequestrant properties, was studied in 30 male F 1 B Golden Syrian hamsters for its effect on plasma lipid concentrations and early atherogenesis in experiment 1. In experiment 2, 30 male Golden Syrian hamsters were studied for the effects on plasma lipids and fecal excretion of bile acids. In experiment 1, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 5% coconut oil and 0.1% cholesterol for 6 weeks. After 6 weeks, hamsters were continued on the diet with either 0% drug (hypercholesterolemic diet [HCD]), 0.5% cholestyramine (CSTY), or 0.5% Cholazol H for 8 weeks. Fasting plasma lipids were measured at weeks 6, 10, and 14, and early atherosclerosis (fatty streak formation) was measured at week 14. Relative to HCD, CSTY and Cholazol H significantly lowered plasma total cholesterol (TC) (−37%, P < .03, and −30%, P < .04, respectively) and plasma very—low and low-density lipoprotein-cholesterol (nonHDL-Cl (−45%, P < .02, and −36%, P < .03, respectively) with no significant effects on plasma HDL-C or triglycerides (TG). Despite similar reductions in nonHDL-C, only Cholazol H significantly prevented early atherosclerosis (−38%, P < .02) relative to HCD. In experiment 2, three groups of 10 hamsters each were fed a chow-based hypercholesterolemic diet supplemented with 10% coconut oil and 0.05% cholesterol and either 0% drug HCD, 0.5% CSTY, or 0.5% Cholazol H for 4 weeks. Fasting plasma lipids were measured at weeks 2 and 4, and fecal bile acids were measured at week 4. Both Cholazol H and CSTY were equally effective in significantly lowering plasma TC (−16%, P < .003, and −13%, P < .01, respectively) and nonHDL-C (−22%, P < .004, and −18%, P < .02, respectively), with no significant effect on HDL-C and TG relative to HCD. Cholazol H and CSTY produced a significantly greater concentration of fecal total bile acids (39%, P < .001, and 28%, P < .002, respectively) relative to HCD. Also, there was a 48% ( P < .002) and 65% ( P < .001) greater fecal concentration of cholic acid (CA) for Cholazol H—treated hamsters compared with HCD- and CSTY-treated hamsters, respectively. Cholazol H also significantly increased fecal concentration of deoxycholic acid (DCA; 56%, P < .02) compared with HCD. In summary, Cholazol H is as effective as CSTY for prevention of diet-induced hypercholesteorlemia and early atherosclerosis in hamsters.

Delta 4-3-oxosteroid 5 beta-reductase deficiency: failure of ursodeoxycholic acid treatment and response to chenodeoxycholic acid plus cholic acid.

In some infants with liver disease, 3-oxo-delta 4 bile acids are the major bile acids in urine, a phenomenon attributed to reduced activity of the delta 4-3-oxosteroid 5 beta-reductase required for synthesis of chenodeoxycholic acid and cholic acid. These patients form a heterogeneous group. Many have a known cause of hepatic dysfunction and plasma concentrations of chenodeoxycholic acid and cholic acid that are actually greater than those of the 3-oxo-delta 4 bile acids. It is unlikely that these patients have a primary genetic deficiency of the 5 beta-reductase enzyme. To document the bile acid profile, clinical phenotype, and response to treatment of an infant with cholestasis, increased plasma concentrations of 3-oxo-delta 4 bile acids, low plasma concentrations of chenodeoxycholic acid and cholic acid, and no other identifiable cause of liver disease. This infant was compared with normal infants and infants with cholestasis of known cause. Analysis of bile acids by liquid secondary ionisation mass spectrometry and gas chromatography-mass spectrometry. The plasma bile acid profile of the patient was unique. She had chronic cholestatic liver disease associated with malabsorption of vitamins D and E and a normal gamma-glutamyltranspeptidase when the transaminases were increased. The liver disease failed to improve with ursodeoxycholic acid but responded to a combination of chenodeoxycholic acid and cholic acid. Treatment of primary 5 beta-reductase deficiency requires the use of bile acids that inhibit cholesterol 7 alpha-hydroxylase.

Familial Giant Cell Hepatitis with Low Bile Acid Concentrations and Increased Urinary Excretion of Specific Bile Alcohols: A New Inborn Error of Bile Acid Synthesis?

A 9-wk-old infant with familial giant cell hepatitis and severe intrahepatic cholestasis had low plasma concentrations of chenodeoxycholic acid and cholic acid and elevated plasma concentrations of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24 zeta-tetrol, and 5 beta-cholest-24-ene-3 alpha,7 alpha,12 alpha-triol. Analysis of the urine by fast atom bombardment mass spectrometry and by gas chromatography-mass spectrometry after treatment with Helix pomatia glucuronidase/sulfatase showed that the major cholanoids in urine were the glucuronides of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24S,25-pentol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol, and 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24 zeta-tetrol. These results are consistent with an inborn error of the 25-hydroxylase pathway for bile acid synthesis, specifically one of the enzymes responsible for conversion of 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24S,25-pentol to cholic acid and acetone. Treatment with chenodeoxycholic acid was tried on two occasions. On the first it appeared to precipitate a rise in bilirubin, on the second the liver function tests improved and the improvement was maintained when the treatment was modified to a combination of chenodeoxycholic acid and cholic acid and finally, cholic acid alone. Despite the normalization of liver function tests, a liver biopsy at 1.25 y showed an active cirrhosis. Nonetheless, the child is thriving at the age of 3.5 y, whereas an affected sibling died at 13 mo.

Liver function tests and urinary albumin in house painters with previous heavy exposure to organic solvents.

The serum activities or concentrations of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), alkaline phosphatase (ALP), albumin, gamma-glutamyl transpeptidase (GGT), bilirubin (BIL), cholic acid (CHOL), chenodeoxycholic acid (CHENO), and transferrin with isoelectric point 5.7, and the urinary excretion of albumin were determined among male current or former house painters (n = 135) and house carpenters (n = 71) who had worked in their trades for at least 10 years before 1970. Workers who showed a value above the 90th percentile among the carpenters in at least one of the tests ASAT, ALAT, GGT, BIL, CHOL, or CHENO were regarded as showing "possible signs of liver dysfunction". Each participant's lifetime solvent exposure was evaluated by interview. The painters were divided into categories with low, intermediate, and heavy cumulative exposure during life (LTSE) or during the most exposed year (MEYSE). All participants stated none or slight recent exposure. The prevalence of possible signs of liver dysfunction increased with solvent exposure category according to LTSE as well as MEYSE with a numerically higher risk estimate in the heavy exposure category for MEYSE than for LTSE. ALP activity increased with exposure category according to both exposure estimates. This increase seemed to be due to an interaction between exposure to solvents and current or previous long term intake of medicines potentially toxic to the liver. None of these results was affected by whether or not the subjects had been exposed to solvents during the year before the investigation. The exposure to solvents was not significantly related to any other outcome variable. It is concluded that long term heavy exposure to solvents may elicit changes in conventional liver function tests indicative of a mild chronic effect on the liver. The findings also suggest that heavy solvent exposure during short time periods is a more likely cause of the findings than lifetime cumulative solvent exposure and that an interaction between solvent exposure and medicines potentially harmful to the liver may be important in the causation of the effects.

Changes in bile acids metabolism during rat hepatocarcinogenesis: Causative or unrelated?

In the present paper, we have aimed at studying the variations in the metabolism of bile acids occuring during an hepatocarcinogenic process induced in male Wistar Rats by the biphasic protocol of Solt and Farber. Bile acids concentrations was measured in the liver. The most significant changes have been observed 5 weeks after the benining of the treatment, it means one week after the selection treatment consisting in 2-acetylaminofluorene administration : the increase in cholic acid, and of its intestinal metabolite, deoxycholic acid, and of α- and β- muricholic acids, are likely to be a consequence of an acute effect of 2acetylaminofluorene. To test for the putative implication of liver bile acids modifications in the selection effect of 2-acetylaminofluorene, diethyl-nitrosamine-pretreated rats were fed a diet containing 1% lithocholic acid, a treatment that induces essentially the same qualitative changes in liver bile acids, as 2-acetylaminofluorene does : no selection effect of lithocholic acid could be demonstrated. These results suggest that changes in bile acid metabolism occuring early in hepatocarcinogenesis are more likely to be secondary than causative events. The same conclusion comes from the results obtained later on in the process, where there is only a high increase in liver cholic acid and deoxycholic acid concentrations.

Effects of oral calcium supplementation on intestinal bile acids and cytolytic activity of fecal water in patients with adenomatous polyps of the colon

Calcium has been proposed to prevent colon cancer in subjects at risk for this tumour. This effect is supposed to be due at least in part to binding the bile acids to calcium, making them insoluble and harmless. To evaluate the effects of oral calcium supplementation on intestinal bile acids, 19 patients with adenomatous colonic polyps were supplemented with 35.5 mmol Ca2+ daily for 12 weeks. Duodenal bile, 24-h feces and 24-h urine were collected before and at the end of the 12-week period. In duodenal bile proportional concentration of cholic acid increased (38 +/- 4 vs. 51 +/- 3%, P < 0.001), whereas that of chenodeoxycholic acid decreased (35 +/- 3 vs. 25 +/- 2%, P < 0.01). Total fecal bile acid excretion increased (950 +/- 126 vs. 1218 +/- 137 mumol 24 h-1, P < 0.01), with proportional concentrations of the main primary and secondary bile acids remaining the same. Cytolytic activity of fecal water, measured by the degree of lysis of erythrocytes by the water, decreased (45 +/- 8 vs. 30 +/- 7%, P < 0.05). Total excretion of calcium increased as expected from the supplementary dose. It is concluded that calcium supplementation markedly affects intestinal bile acids and lytic activity of fecal water and that, in view of similar results during 1-week calcium supplementation in young healthy subjects, these effects remain constant over at least 3 months and occur both in healthy persons and in patients at increased risk for colon cancer.

Role of endocardial endothelium in the positive inotropic effect of cholic acid in isolated myocardium.

In isolated feline right ventricular papillary muscles, with intact or damaged (exposure to dry air for 30 s) endocardium, the effects of cholic acid were studied. At 35 degrees C and a [Ca2+] of 1.25 mM, isometric twitches and the maximal unloaded velocity of shortening (Vmax) were registered. Endocardial endothelium (EE) and myocardial ultrastructure were evaluated on scanning and transmission electron microscopy. In muscles with intact EE, low concentrations of cholic acid (3 x 10(-9) to 3 x 10(-7) M) or short incubation (30 min) with 3 x 10(-8) M induced a mild positive inotropic response, manifested as an increased peak isometric twitch tension (TT) and shortened twitch duration, without changes in Vmax. This inotropic response was abolished by damaging the EE. It was also absent after the addition of propranolol to muscles with intact EE. Higher concentrations (3 x 10(-6) to 3 x 10(-4) M) or prolonged incubation at 3 x 10(-8) M caused extensive morphologic damage of the EE, without detectable impairment of subjacent myocardium. This was accompanied by a progressive decrease in the TT and further twitch abbreviation, without changes in Vmax, resembling twitches obtained from muscles with experimentally damaged EE. These observations suggest that cholic acid induces an EE-dependent and beta-receptor-mediated positive inotropic effect, while simultaneously causing damage to EE cells.

Preparation and Evaluation of Oral Dosage Form Using Acylglycerols. II. Effect of Food Ingestion on Dissolution and Absorption of Aspirin from the Granules Prepared by Acylglycerols in Human Subjects.

The dissolution behavior of the aspirin enteric granule prepared using acylglycerols, glyceryl monostearate (GMS) and glyceryl trilaurate (GTL), was investigated in vitro and in human subjects in a fasting or non-fasting state. Aspirin was slowly released from the granule in vitro at pH 1.2. No acceleration of the aspirin dissolution rate in the medium without lipase and cholic acid was observed when the pH level of the medium increased to a neutral region (pH 6.4). However, the dissolution of aspirin was significantly increased by increasing the concentrations of lipase and cholic acid in the medium. Lipase appears to play an essential role in the dissolution process of aspirin granules. In human subjects, the average levels of the cumulative amount of total salicylate excreted in a urine-time curve, and the mean residence time (MRT) obtained after oral administration of a granule in the fasting state were markedly delayed in comparison with the results observed using an aqueous solution and a crystalline form of aspirin. In comparing the fasting condition with the non-fasting condition (after food ingestion), no significant difference was recognized in the total amount of salicylate excreted in urine to an infinite time (Ae(infinity)), whether the MRT was obtained by granule, crystalline form or aqueous solution. It can be concluded that aspirin granule prepared by GMS and GTL has a property of pancreatic lipase-sensitive dissolution, and its bioavailability is unaffected by food intake.

Decreased concentrations of deoxycholic acid in serum of uraemic patients with diarrhoea

The fasting peripheral serum concentrations of cholic acid, chenodeoxycholic acid, deoxycholic acid and ursodeoxycholic acid were determined in a total of 32 patients with uraemia. Eighteen of the patients suffered from diarrhoea. A highly accurate and specific mass-fragmentographic technique with high sensitivity was used to measure the concentrations of the individual bile acids. The total amount of bile acids was normal in the two groups of patients. Patients with diarrhoea had 50% lower concentrations of deoxycholic acid than a corresponding group of healthy subjects. It is suggested that the low level of deoxycholic acid may contribute to diarrhoea in these patients.

Binding and solubility of oleic acid to laboratory materials: A possible artifact

The possibility that significant amounts of fatty acids were dissolved in or bound to the surfaces of common laboratory materials was examined. The uptake or adsorption of radioisotopically labeled oleic acid and cholic acid by plastic tubing of Tygon™, Teflon™, and polyethylene, and Pyrex™, and borosilicate glass, and steel was measured. 3H-oleic acid and 14C-cholic acid were used in the presence of different concentrations of unlabeled oleic acid, cholic acid, and/or bovine serum albumin. Concentrations, composition, pH, and perfusion rates were varied. Relatively large amounts (10–95 %) of oleic acid (25 μM) were lost by dissolving in plastic and adsorption to glass or metal. The degree of losses decreased in the presence of compounds in the perfusion solution which could bind or dissolve oleic acid. In contrast, cholic acid was not lost to plastic, glass or metal. The magnitude of and influence of perfusion rate, composition, pH, and sequence of perfusion solutions on oleic acid losses were sufficiently large that the results of certain studies, such as those of unstirred water layers or albumin - stimulated fatty acid uptake by hepatocytes may need to be reexamined.

Hepatic bile acid metabolism during early development revealed from the analysis of human fetal gallbladder bile.

A detailed study of the qualitative and quantitative composition of bile acids in human fetal gallbladder bile is described. Bile was collected during early gestation (weeks 16-19) and analyzed by gas chromatography and mass spectrometry, fast atom bombardment ionization mass spectrometry, and high performance liquid chromatography. Bile acids were separated into different conjugate groups by chromatography on the lipophilic anion exchange gel, diethylaminohydroxypropyl Sephadex LH-20. Quantitatively more than 80% of the bile acids were secreted into bile conjugated to taurine. Unconjugated bile acids and glycine conjugates accounted for 5-10% of the total biliary bile acids. Bile acid sulfates were present only in trace amounts indicating that quantitatively sulfation is not an important pathway in bile acid metabolism during development. Total biliary bile acid concentrations were low (0.1-0.4 mM) when compared to reported values for adult bile (greater than 10 mM). Chenodeoxycholic acid was the major biliary bile acid and exceeded cholic acid concentrations by 1.43-fold indicating either a relative immaturity in 12 alpha-hydroxylase activity during early life or a dominance of alternative pathways for chenodeoxycholic acid synthesis. A relatively large proportion of the biliary bile acids comprised metabolites not found in adult bile. The presence of relatively high proportions of hyocholic acid (often greater than cholic acid) and several 1 beta-hydroxycholanoic acid isomers indicates that C-1 and C-6 hydroxylation are important pathways in bile acid synthesis during development. We describe, for the first time, evidence for the existence of a C-4 hydroxylation pathway in the metabolism of bile acids, which may be unique to early human development. Mass spectrometry was used to confirm the identification of 3 alpha,4 beta,7 alpha-trihydroxy-5 beta-cholanoic and 3 alpha,4 beta-dihydroxy-5 beta-cholanoic acids. Quantitatively, these C-4 hydroxylated bile acids accounted for 5-15% of the total biliary bile acids of the fetus, suggesting that C-4 hydroxylation is quantitatively an important pathway in the bile acid metabolism during early life.