Concentration Of Cholic Acid Research Articles

The prevention of experimental cholesterol gallstones by ileectomy in mice.

After a lithogenic diet containing 0.5 per cent cholesterol and 0.25 per cent sodium cholate was fed to a group of normal Crj-ICR male mice for 10 days, cholesterol gallstones developed. No formation of gallstones occurred, however, in a group of mice from which 20 cms of terminal ileum had been removed prior to the feeding of the lithogenic diet. The biliary concentrations of cholesterol, phospholipids and bile acids were markedly lower in the ileectomized mice, with the decrease in cholesterol concentration being most significant. On the other hand, fecal excretion of sterols and bile acids increased in the ileectomized mice. The pool size of bile acids increased after the feeding of the lithogenic diet, but ileectomy decreased the pool size in mice fed the ordinary or lithogenic diets. The biliary concentration of cholic acid increased after the feeding of the lithogenic diet, but decreased with ileectomy. The biliary concentration and fecal excretion of deoxycholic acid markedly increased, while those of beta-muricholic acid and its secondary bile acids, omega-muricholic acid and hyodeoxycholic acid, decreased. The increase in plasma and liver cholesterol levels after the feeding of the lithogenic diet was prevented by ileectomy. These data suggest that ileectomy prevents the formation of cholesterol gallstones after the feeding of a lithogenic diet due to a decrease in cholic acid absorption.

Age and Diet Effects on Fecal Bile Acids in Infants

SummaryFecal bile acid patterns and concentrations have been determined for 28 infants who were followed from average ages of 3–11 months. Half were solely breast‐fed and half were solely formula‐fed at the beginning of the study. Breast‐fed infants were found to have significantly (p < 0.05) lower concentrations of cholic acid than the formula‐fed group, up to an average age of 5 months. Concentrations of deoxycholic and lithocholic acids were directionally lower in breast‐fed infants at all ages. Concentrations of chenodeoxycholic acid were similar for both groups throughout the study. At the end of the study, breast‐fed infants were excreting 17% of their total bile acids in the form of secondary acids, compared to 33% for formula‐fed infants. This pattern persisted long after the infants began weaning. Formula‐fed infants were found to have lithocholic acid in their stools at a significantly (p < 0.05) earlier age than breast‐fed infants. Appearance of deoxycholic acid was at similar ages for both groups. Both of these secondary acids were found to occur at much younger ages (approximately 2 months) than has been previously reported. These observed differences are attributed to the distinct intestinal microbial populations encouraged by the different diets.

7-Methyl bile acids: 7 beta-methyl-cholic acid inhibits bacterial 7-dehydroxylation of cholic acid and chenodeoxycholic acid in the hamster.

The effect of dietary 7 beta-methyl-cholic acid [0.075% in rodent chow (6.4 mg/animal per day)] on cholesterol and bile acid metabolism was studied and compared with that of cholic acid in the hamster. Following oral administration of 7 beta-methyl-cholic acid for 3 weeks, the glycine-conjugated bile acid analog became a major constituent of gallbladder bile. Biliary cholic acid concentration decreased significantly, while that of chenodeoxycholic acid remained unchanged. Serum and liver cholesterol levels were increased by dietary 7 beta-methyl-cholic acid and by cholic acid. Hepatic microsomal HMG-CoA reductase activity was inhibited (30% of the control value) by both bile acids; cholesterol 7 alpha-hydroxylase activity was not affected. In chow controls and cholic acid-fed animals, bacterial 7-dehydroxylation of [14C]chenodeoxycholic acid and [14C]cholic acid was nearly complete. In contrast, dietary 7 beta-methyl-cholic acid effectively prevented the 7-dehydroxylation of the two primary bile acids. These results show that dietary 7 beta-methyl-cholic acid is preserved in the enterohepatic circulation and has an effect on serum and liver cholesterol concentrations similar to those produced by the naturally occurring cholic acid. 7 beta-Methyl-cholic acid is an efficient inhibitor of the bacterial 7-dehydroxylation of the primary bile acids in the hamster.

Development of active and passive transport of bile acids in rabbit intestine

Previous studies have indicated that saturable, Na +-bile acid coupled transport is absent in the ileum throughout most of the suckling period and that the maturation of ileal bile acid uptake which occurs during weaning results primarily through an increase in functional bile acid carriers within the ileal brush border membrane. This study was undertaken in weanling and adult rabbits to establish the effect of maturation on the active ileal and passive jejunal and colonic uptake of 8 bile acids. The in vitro uptake of a range of concentrations of cholic (C), taurocholic (TC), glycocholic (GC), chenodeoxycholic (CDC), taurochenodeoxycholic (TCDC), glychochenodeoxycholic (GCDC), deoxycholic (DC) and taurodeoxycholic (TDC) acid was determined. Active ileal uptake of C, TC, GC, DC and TDC was greater in adult that in weanling animals, whereas uptake of CDC, TCDC and GCDC was similar in both groups. The relative permeability for passive uptake of bile acids into the jejunum and colon was similar in young and adult rabbits. Jejunal mucosal surface area was similar in the two groups, but was greater in the ileum in the adult than in the weanling rabbits due to an increase in villus height, width, and number of villi per unit serosal length. However, the age-associated differences in active bile acid uptake were not explained simply on the basis of these differences in ileal mucosal surface area or the concentration of bile acids in the intestinal lumen. Thus, maturation of the rabbit from weanling to adulthood does not influence the relative passive permeability of the jejunum or colon to bile acids, but does increase active ileal uptake of conjugated and unconjugated cholic acid and deoxycholic acid, but not chenodeoxycholic acid

Intestinal involvement in progressive systemic sclerosis detected by increased unconjugated serum bile acids.

In patients with progressive systemic sclerosis, impaired motor function of the small intestine may lead to bacterial overgrowth causing diarrhoea, steatorrhoea and malabsorption. As unconjugated serum bile acids have been proposed as markers for small bowel bacterial overgrowth, we studied individual unconjugated serum bile acids in 36 patients with progressive systemic sclerosis. These patients had significantly higher serum concentrations of unconjugated cholic acid (median 0.18; range 0.05-30.75 v 0.09; 0.01-0.19 mumol/l, p less than 0.001) and chenodeoxycholic acid (0.10; 0.01-6.83 v 0.04; 0.01-0.39 mumol/l, p less than 0.025) than healthy controls (n = 16). This difference was mainly due to patients with diarrhoea (n = 10), who had significantly higher concentrations of unconjugated serum bile acids than patients with normal bowel habit (cholic acid median 0.55 v 0.16 mumol/l, p less than 0.001; chenodeoxycholic acid 0.75 v 0.07 mumol/l; p less than 0.005). All patients with raised unconjugated serum bile acids had oesophageal motility disorders. These results confirm a relationship between motility disorders and bacterial overgrowth in patients with progressive systemic sclerosis.

Bile acid conjugates present in tissues during extrahepatic cholestasis.

Bile acid concentrations in the muscle, subcutaneous fat and skin of patients with extrahepatic cholestasis were compared to those in serum. High concentrations were found in most tissue samples. In tissues from patients administered [24-14C]chenodeoxycholic acid, the specific activity was lower than that in serum, indicating a storage of bile acids in these tissues. In some patients, higher concentrations of bile acids were found in tissue samples than in serum. This was mainly due to increased concentrations of cholic acid. Monohydroxy bile acids were not found in increased concentrations. Bile acids covalently bound to tissues were not detected.

Preparation of 12-ketochenodeoxycholic acid from cholic acid using coimmobilized 12α-hydroxysteroid dehydrogenase and glutamate dehydrogenase with NADP + cycling at high efficiency

12-Ketochenodeoxycholic acid, an essential intermediate in the synthesis of chenodeoxycholic acid, has been enzymatically prepared from cholic acid. The specific oxidation of the 12α-hydroxyl group of cholic acid with NADP + was catalysed by 12α-hydroxysteroid dehydrogenase (12α-hydroxysteroid: NAD + oxidoreductase, EC 1.1.1.176), and the regeneration of NADP + was obtained through the glutamate dehydrogenase ( l-glutamate:NADP + oxidoreductase, EC 1.4.1.4) catalysed reduction of α-ketoglutarate. The two enzymes were immobilized onto Sepharose CL-4B activated with tresyl chloride. The coimmobilized enzymes showed a cycling efficiency for the coenzyme similar to that of the free enzymes. High concentrations of cholic acid (up to 4%, w/v) were completely and specifically transformed into the 12-keto derivative using amounts of cofactor about 1600 times lower on a molar basis. The immobilized enzymes maintained ∼70% of the initial activity after 2 months of continuous use.

Serum unconjugated bile acids: Qualitative and quantitative profiles in ileal resection and bacterial overgrowth

Qualitative and quantitative profiles of unconjugated bile acids in the serum obtained over a 24-h period from three patients with ileal resections and one with a bacterial overgrowth are described. Unconjugated serum bile acids were determined using the high sensitivity and resolution of capillary column gas liquid chromatography after their rapid extraction and isolation using reverse phase octadecylsilane bonded silica cartridges and the lipophilic gel Lipidex 1000. Unconjugated serum bile acid concentrations were elevated throughout the day in both ileum resected patients and in conditions involving bacterial overgrowth when compared to healthy subjects. Total conjugated cholic acid concentrations were expectedly low in both intestinal disorders and were without the postprandial increases generally observed in healthy subjects. Qualitative gas Chromatographic profiles of serum unconjugated bile acids in bacterial overgrowth distinctly revealed a predominance of deoxycholic acid and other secondary bile acids in all samples, while, in conditions of an impaired enterohepatic circulation, deoxycholic acid was absent or present in only trace amounts. The potential significance of measuring serum unconjugated bile acids in intestinal disorders is discussed.

Portal venous bile acids in cholesterol gallstone disease: effect of treatment with chenodeoxycholic and cholic acids.

We determined the serum concentrations of cholic, chenodeoxycholic and deoxycholic acids in portal and peripheral venous blood in 9 gallstone-free patients and 39 patients with cholesterol gallstones during standardized cholecystectomy. An accurate and specific gas chromatographic-mass spectrometric technique was used. The portal venous concentration of total bile acids was similar in gallstone-free and untreated gallstone patients (n = 20); there was no evidence of a reduced hepatic uptake of bile acids in the latter. Treatment with cholic acid (n = 10) was associated with a 70% increase in cholic acid and normal concentration of total bile acids. In chenodeoxycholic acid-treated patients (n = 9), the portal venous concentration of this bile acid was increased 3-fold; total bile acids were increased about 60%. The estimated hepatic uptake of cholic acid was slightly decreased during chenodeoxycholic acid treatment. The results indicate that neither bile acid inflow to the liver nor hepatic bile acid uptake is reduced in fasting patients with cholesterol gallstones, and treatment with chenodeoxycholic acid increases fasting inflow of bile acids to the liver. The latter may contribute to unsaturation of fasting hepatic bile during treatment with chenodeoxycholic acid.

Effect of bile acids on formation of the mutagen, quercetin, from two flavonol glycoside precursors by human gut bacterial preparations

Human fecal cultures, induced with either of the flavonols, quercitrin or rutin, were grown in the presence of various concentrations of chenodeoxycholic acid, deoxycholic acid or cholic acid. Cell-free preparations (fecal preparations) from these cultures were then incubated with rutin or quercitrin. The formation of the aglycone, quercetin, was monitored by the Ames assay using tester strain TA98. The presence of chenodeoxycholic or deoxycholic acids in the quercitrin-induced culture resulted in a fecal preparation which enhanced the mutagenesis of quercitrin approximately two-fold at optimal concentrations of 0.6 mM and 0.8 mM respectively. Higher concentrations of these bile acids decreased the activity of the fecal preparations. Cholic acid gave similar results except a much higher concentration (3.0 mM) was required to achieve this effect. Analogous results with rutin-induced cultures were less clear cut: considerable variation in bile acid effect was noted among volunteers. The authors propose that bile acid in the medium may enhance the ability of rutin- and quercitrin-glycosidase elaborating organisms to successfully compete with other microbial populations. Additionally, the greater variation in results using rutin as inducer may reflect more heterogeneous populations of organisms active against this substrate. The possible role of bile acids and flavonols in bowel cancer is discussed.

Bile acid induction of 7 alpha- and 7 beta-hydroxysteroid dehydrogenases in Clostridium limosum.

When grown in the presence of bile acids, two strains of Clostridium limosum were found to contain significant amounts of NADP-dependent 7 alpha/7 beta-hydroxysteroid dehydrogenase and NAD-dependent 7 alpha-hydroxysteroid dehydrogenase which were active against conjugated and unconjugated bile acids. No measurable activity could be found when deoxycholic acid (3 alpha, 12 alpha-dihydroxy-5 beta-cholan-24-oic acid) was used as substrate. No 7 beta-hydroxysteroid dehydrogenase activity and only a trace of 7 alpha-hydroxysteroid dehydrogenase activity could be demonstrated when bile acid was deleted from the growth medium. If bile acid was added after the time of inoculation, the amounts of 7 alpha/7 beta-hydroxysteroid dehydrogenase were greatly reduced. Enzyme enhancement was blocked by addition of rifampicin. The 7 alpha/7 beta-hydroxysteroid dehydrogenase components had pH optima of approximately 10.5. Both the 7 alpha/7 beta-hydroxysteroid dehydrogenase activities were heat-labile, with the 7 beta-component being the more stable of the two. When ranked according to the level of enzymes induced, the order in increasing bile acid induction power on an equimolar scale (0.4 mM) was: 7-ketodeoxycholic acid, cholic acid, chenodeoxycholic acid, and deoxycholic acid. Both 7-ketolithocholic acid and ursodeoxycholic acid were ineffective as enzyme inducers. Optimal induction was achieved with high concentrations of cholic acid (5 mM) and a harvest time of 24 hr. Addition of ursodeoxycholic acid to medium containing optimal concentrations of deoxycholic acid suppressed enzyme induction.(ABSTRACT TRUNCATED AT 250 WORDS)

Gallbladder function and maternal bile acids in intrahepatic cholestasis of pregnancy

Ultrasonic measurement of the gallbladder volume was taken in 8 nonpregnant, healthy women, in 7 women with normal pregnancies and in 7 women whose pregnancies were complicated by intrahepatic cholestasis of pregnancy, in the fasting state and 30, 60, 120 and 180 rain after a test meal. At the same time the serum concentrations of cholic acid and chenodeoxycholic acid were measured. The fasting and ejection volumes of the gallbladder in cholestasis of pregnancy were greater than in normal pregnancy. The fasting volume of the gallbladder was greater, but the ejection volume smaller in normal pregnancy than in nonpregnant women. No difference in the ultrasonic appearence of the intra- and extrahepatic bile ducts was found between the groups. Serum bile acids were increased in cholestasis of pregnancy and did not display any decreasing tendency after the postprandial rise during the following 3 h. The results indicate that in cholestasis of pregnancy the gallbladder function and the enterohepatic circulation of bile acids are different from normal pregnancy. This may be associated with the great tendency to gallstones in these women. The large size of the gallbladder in cholestasis of pregnancy has differential diagnostic importance in the ultrasonic evaluation of a pregnant woman with liver disease.

Raised serum bile acid concentrations after occupational exposure to styrene: a possible sign of hepatotoxicity?

Fasting serum concentrations of conjugated bile acids were investigated in 23 men who had been exposed to styrene and compared with the concentrations in 60 non-exposed individuals. Eleven of the exposed subjects had raised concentrations of either cholic acid or chenodeoxycholic acid or both. There were no indications of alcohol abuse, drug intake, or undiagnosed liver disease. It is possible, therefore, that the raised bile acid concentrations were due to exposure to styrene. This would support the concept that occupational exposure to styrene may affect the liver and point to the possibility that raised serum bile acid concentrations might be a sensitive and early indicator of hepatic injury in individuals exposed to organic solvents.

Styrene exposure and the liver.

The liver functions, as reflected by the serum enzyme activities of aspartate aminotranferase, alanine aminotransferase, and gamma glutamyl transferase and by the concentrations of cholic acid and deoxycholic acid, of 34 styrene-exposed and 34 reference female workers were followed prospectively for a year. The mean age of exposed workers was 34.2 years, mean duration of past exposure 5.1 years. The mean age of the referents was 30.7 years. During the follow-up period blood samples were collected three times for the determinations. The history of possible liver disease and alcohol consumption was ascertained by questionnaire. Altogether 87 samples of both groups were analyzed. The styrene-exposed group did not have higher values for any measurement when compared with those of the referents. Two persons in both groups had one sample with transaminase activities exceeding laboratory reference values. The abnormal values were associated with the use of drugs or alcohol. Cholic acid and chenodeoxycholic acid concentrations were of the same magnitude in both groups.

Effect of Blackgram Fiber (Phaseolus mungo) on Hepatic Hydroxymethylglutaryl-CoA Reductase Activity, Cholesterogenesis and Cholesterol Degradation in Rats

Rats maintained on cholesterol-free diet and fed neutral detergent fiber (NDF) from blackgram showed lower concentrations of cholesterol in the serum, liver and aorta, when compared to those fed isocaloric, fiber-free diet. Incorporation of labeled precursors, [1,2-14C]acetate and [U-14C]glucose, into cholesterol of liver was higher in these rats. The activity of hepatic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase was also increased. Concentration of cholic acid and chenodeoxycholic acid in the liver was also more in rats fed blackgram NDF. The decreased concentration of cholesterol in the tissues may be due to its higher rate of hepatic degradation to bile acids.

Interaction of hemolytic anemia and genotype on hemolysis-induced gallstone formation in mice

We previously reported that nb/nb mice with hereditary hemolytic anemia spontaneously developed calcium bilirubinate pigment gallstones. To assess the extent to which gallstone formation and bile composition is gene dependent, we transferred the hemolytic process by transplanting bone marrow from nb/nb mice into a nonhemolytic, but histocompatible genotype, W/Wv mice. Hematologic parameters of transplanted W/Wv mice were nearly identical to those of nb/nb mice. Like nb/nb mice, the percentage of transplanted mice with gallstones increased with the duration of the hemolysis and occurred twice as often in female mice as in male mice (37% vs. 19%; p < 0.05). However, the rate of gallstone formation in transplanted mice was one-third less than that in nb/nb mice (3.6% per month vs. 5.5%; p < 0.05). Analysis of hepatic bile revealed that (a) marrow-transplanted mice had higher concentrations of unconjugated bilirubin due to hemolysis (p < 0.05) and of total bile acids determined by the W/Wv genotype (p < 0.001) than their respective nb/nb counterparts and (b) transplanted mice with stones had a significantly lower proportion of cholic acid (p < 0.005) and higher proportion of keto-bile acids (p < 0.005) than transplanted mice without stones, suggesting that the cholic acid concentration may retard stone formation. These data indicate that the hemolytic process is the primary determinant of pigment gallstone formation in these mice and is influenced by the following factors; (a) duration of the hemolytic process, (b) gender, and (c) the genotype that regulates the composition of biliary components like bile acids.

Early morphologic and enzymatic changes in livers of rats treated with chenodeoxycholic and ursodeoxycholic acids.

The effect of high doses of chenodeoxycholic and ursodeoxycholic acids on hepatic morphology and on cholesterol and bile acid metabolism was examined in the rat. After 2 weeks of either cheno or ursodeoxycholic acid feeding, the livers of the treated rats revealed marked proliferation of the smooth endoplasmic reticulum which appeared as an adaptation phenomenon of the microsomal enzyme system in response to bile acid intake. However, the livers of the chenodeoxycholic acid-treated rats showed early alteration that included mild triaditis, swelling of the bile canalicular microvilli, distended Golgi vesicles, whorling of the mitochondria, and presence of large vacuoles bound by single membranes. During cheno- or ursodeoxycholic acid treatment, the administered bile acid predominated in the bile and amounted to 79 or 67% of the biliary bile acids, respectively. At the same time, the concentration of the muricholic acids was also increased. Biliary cholic acid content dropped significantly, but no change in lithocholic acid concentration was observed. In addition, the activity of HMG-CoA reductase as well as that of cholesterol-7 alpha-hydroxylase was reduced by either of the administered bile acids, while no change in hepatic cholesterol content was detected, and intestinal cholesterol absorption was not significantly different from that of controls. These results show that cheno- and ursodeoxycholic acids inhibited hepatic cholesterol and bile acid synthesis but did not increase either intestinal cholesterol absorption or hepatic microsomal cholesterol content. Since the amounts of biliary lithocholic acid were similar in the bile acid-treated animals, the morphologic abnormalities detected in the chenodeoxycholic acid-fed rats are probably due to an increased pool of chenodeoxycholic acid. However, lithocholic acid-induced liver injury cannot be excluded.

Low serum cholic acid concentration of Duchenne muscular dystrophy

Serum bile acids of 15 patients with Duchenne muscular dystrophy (DMD) were analyzed by gas-liquid chromatography. The serum cholic acid values were unusually low (0.16 +/- 0.13 microM), even less than 0.01 microgram/ml in 4, compared with controls (1.47 +/- 0.17 microM). HDL-cholesterol was within normal limits. The low concentration of serum cholic acid may be causative of abnormal calcium mobilization in DMD. The intracellular calcium mobilization seems to be affected by serum cholic acid as indicated by the enhanced rate of loss of intracellular calcium from the muscle exposed to cholic acid, which acts as a calcium-ionophore and reversibly forms soluble complexes with calcium ions.

Lymphatic transport of bile acids in man

The possibility of a lymphatic transport of bile acids in man was investigated. Four patients were studied 2-4 weeks after renal transplantation. As a part of the postoperative immunosuppressive treatment they all had a thoracic duct fistula for lymphatic drainage. After a standardized meal, lymph and peripheral blood samples were simultaneously collected at 30-minute intervals for 210 minutes. The bile acids, cholic acid, chenodeoxycholic acid, and deoxycholic acid were assayed by a gas-liquid chromatography-mass spectrometry method using deuterium-labeled internal standards. The concentration of cholic acid was about the same in lymph and serum. The concentrations of chenodeoxycholic and deoxycholic acids were 2-3 times higher in lymph than in serum, both in the fasting state and postprandially. These results are explained by a more efficient passive absorption of the less polar dihydroxy bile acids. The transport of bile acids in the lymph was calculated to be only about 0.2% of that in the portal vein.

Cholestyramine Treatment Reduces Postprandial but not Fasting Serum Bile Acid Levels in Humans

Fasting serum concentrations of cholic acid, chenodeoxycholic acid, and deoxycholic acid were determined in healthy subjects and in patients with familial hypercholesterolemia before and during treatment with cholestyramine. The bile acids were analyzed by a specific isotope-dilution technique by using gas chromatography-mass spectrometry. Cholestyramine treatment did not change the fasting concentration of total bile acids, but the contribution of cholic acid was increased; those of chenodeoxycholic acid and deoxycholic acid were decreased. No decrease of fasting bile-acid concentrations in portal venous serum was seen in 2 cholestyramine-treated gallstone patients. The postprandial total bile-acid concentration was about 40% lower during cholestyramine treatment in healthy subjects, reflecting a reduced postprandial inflow of bile acids to the liver. This degree of interruption of the postprandial enterohepatic circulation may be sufficient to produce a near maximal bile-acid biosynthesis rate and to promote lowering of plasma cholesterol also in the fasting state. It is concluded that the postprandial bile-acid inflow to the liver may be more important as a regulator of bile-acid biosynthesis than is the fasting level of bile acids.