The vagina: effects of progesterone pretreatment and neonatal treatment with estrogen or androgen on [3H] estradiol retention

The paper deals with efficiency of sodium selenite in case of acute damage of the liver in rats as well as with its effect on main functions of the liver in norm and pathology, especially on biligenesis, synthesis and secretion of bile acids, bilirubin and cholesterol. The preparation in doses of 1 and 10 Mg per 100 g of weight is established to produce a normalizing effect of intensity of biliation synthesis and secretion of bile acids, secretion of bilirubin and excretion of cholesterol in the animals with the affected liver. The preparation has a cholagogic effect as well. In the healthy rats sodium selenite increases the intensity of bile secretion, intensifies synthesis and secretion of bile acids and bilirubin. A stimulating effect of the preparation on biligenesis is maintained with the liver dystrophy induced by carbon tetrachloride and polychlorines as well. Under these conditions it is manifested to a greater extent than in the healthy animals.     

Intracerebral Whipple''s disease diagnosed by stereotactic biopsy: a case report and review of the literature

We studied the effects of bile stasis in a guinea pig model of pigment gallstone. The common bile ducts of guinea pigs were partially ligated, and the guinea pigs killed one or two weeks later. Biliary sludge or stones were examined with the Fourier transform infrared spectroscopy and the scanning electromicroscopy. The bile was analyzed for pH, free calcium, bile acids and bilirubin fractions, and the activities of both bacterial and endogenous beta-glucuronidase. After bile duct ligation, calcium bilirubinate precipitates or stones formed in all except one of the animals studied. The bile pH and the proportion of unconjugated bilirubin rose after bile duct ligation, with a concomitant fall of bilirubin monoglucuronide. The activity of bacterial beta-glucuronidase decreased after ligation, while the activity of endogenous beta-glucuronidase rose at week 2. Our results imply that precipitation of calcium bilirubinate in this animal model was induced by an increased bile pH and the nonenzymatic hydrolysis of conjugated bilirubin.     

Bile and bilirubin excretion in relation to hepatic energy status during hemorrhagic shock and hypoxemia in rabbits

OBJECTIVE: We investigated the relation between in vivo hepatocyte excretion of bile and bilirubin and hepatic energy status in rabbit models of hemorrhagic shock and hypoxemia. DESIGN: Randomized animal study. MATERIALS AND METHODS: After creation of a total biliary fistula, hemorrhagic shock with mean pressure of 50 mm Hg (10 rabbits) or hypoxemia with Pao2 at 35 mm Hg (8 rabbits) was induced for 60 minutes. We determined bile flow, excretion of bilirubin and total bile acids, the plasma level of bilirubin, and arterial ketone body ratio, which reflects hepatic mitochondrial function. MEASUREMENTS AND MAIN RESULTS: Both the hemorrhagic shock and the hypoxemic models showed decreases in bile flow and excretion of bilirubin and total bile acids as well as increase in the plasma level of bilirubin in association with decreases in the hepatic energy charge and the arterial ketone body ratio. CONCLUSIONS: Bile flow and the excretion of bilirubin were correlated with the hepatic energy status.     

Hepatic metabolism and transport of bilirubin and other organic anions

Most of bilirubin, bile acids and other organic anions are preferentially taken up by the liver and excreted into bile. Recently many transporters on the sinusoidal and canalicular membranes of the hepatocytes have been reported for each ligand. complementary DNA was cloned for human Na+/taurocholate cotransporting polypeptide (NTCP) which mediates sodium dependent secondary active hepatic uptake of bile acids. For the hepatic uptake of non-bile acid-organic anions such as bilirubin, at least 4 transporters are postulated, i.e., bilirubin/BSP binding protein (BBBP), organic anion binding protein (OABP), bilitranslocase, and organic anion transporting polypeptide (OATP). In the hepatocytes, bilirubin is glucuronidated in the endoplasmic reticulum. The gene for UDP-glucuronosyltransferase (UGT) 1 family has been elucidated and differential splicing from several exons 1 (A to J) results in forming isozymes of UGT 1 including bilirubin UGT. At the canalicular membranes, two main ATP-dependent organic anion transporters have been reported, i.e., canalicular bile salt transporter (cBST) for bile acids and canalicular multispecific organic anion transporter (cMOAT) for non-bile acid organic anions. Recently multidrug resistance protein (MRP) is reported closely related to or identical to cMOAT. These canalicular ATP-dependent transporters are called ABC (ATP-binding cassette) transporters.     

Evaluation of cholesterol absorption in rats using markers labeled with stable isotopes. Effect of complete bile diversion

BACKGROUND/AIMS: An easily performed method to measure cholesterol absorption with isotope labeled cholesterol and beta-sitostanol in humans is described. The first aim of the study was to show whether this method can also be used in rats. Secondly, to see whether complete bile diversion results in a complete loss of cholesterol absorption. METHODOLOGY: Cholesterol absorption was evaluated in rats by the constant isotope feeding method using [2H6]cholesterol and [2H4]sitostanol as markers. Fecal samples were analyzed by gas-chromatography/mass spectrometry. RESULTS: In 8 rats with intact enterohepatic circulation of bile acids, cholesterol absorption averaged 61 (3% (SD) (range: 54-69%)). Complete bile diversion was followed by an almost total loss of cholesterol absorption (5.5+/-0.6%, range: 2.4-6.9%, n=7). CONCLUSIONS: The results indicate that deuterated cholesterol and deuterated sitostanol are reliable markers for measurement of cholesterol absorption in rats and that bile acids are essential for cholesterol absorption.     

Relationship between ANCA and clinical activity in inflammatory bowel disease: variation in prevalence of ANCA and evidence of heterogeneity

The effects of 6 Gy whole-body 60Co gamma irradiation on bile composition in pigs were studied to determine possible alterations in the quality of the bile, which may be a determining factor in diarrhea as well as nutrient malabsorption, which classically occurs after irradiation. The bile duct of pigs was catheterized to allow a total and continuous deviation of bile over several weeks, before and after irradiation. After measurement of the volume and sampling, bile was returned to the animal via a duodenal catheter. Bile samples were then analyzed for cholesterol, phospholipid and total bile acid content. Individual bile acids were quantified by HPLC analysis. Bile flow was significantly decreased during the first 24 h and after the fifth day postirradiation. Whereas cholesterol, phospholipid and total bile acid concentrations were not altered, profiles of individual bile acids were modified significantly as early as the first day postirradiation. Moreover, the change of these profiles with time was specific for each bile acid. Such modifications in bile acid profiles resulted in a change in the properties of the bile acid pool in an increased proportion of dihydroxylated bile acids known to interfere with gut functions, and it is reasonable to suggest that radiation-induced changes in bile acid profiles may be involved in radiation-induced gastrointestinal disorders.     

"Very slow" cholangiography in hyperbilirubinemias and in chronic liver diseases]

The "ultra-slow" method for cholangiography in serious icterus due to chronic heptopathy is described. The results are related to different icterus stages. A comparison is drawn between this and conventional methods for examination of the bile ducts, assuming equal degrees of blood bilirubin.     

Effect of some choleretics on the hepatic flow and its composition in man

Four choleretics, selected at random from the German list of medical preparations, were tested with regards to their influence on hepatic bile production and bile composition. The investigations were performed on patients with a T-drainage in the ductus choledochus after bile duct revision. Bile was collected after fasting (90 min) and after administration of the drugs to be tested (3 hours). The choleretics were administered orally in a dosage two to five times more than the recommended one. Besides the bile volume bile acids, cholesterol, bilirubin, bicarbonate, potassium, sodium and calcium were determined. None of the parameters could be definitely influenced by these drugs. On the other hand a pronounced increase in the bile flow as well as the expected change in the other parameters could be observed after standardized secretion-stimulation which had been additionally carried out in half of the patients (dehydrocholic acid, i.v., taurocholic acid intraduodenally, secretin i.v., meals).     

The programme of quality assurance of the EORTC radiotherapy group. A historical overview

Decreased activity of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in the catabolism of cholesterol to bile acids, is known to result in increased biliary cholesterol concentration and supersaturation of bile. Supersaturation of bile by cholesterol is a necessary condition for cholesterol gallstone formation. In guinea pigs, the hepatic concentration of ascorbic acid affects the catabolism of cholesterol: hypovitaminosis C reduces cholesterol 7 alpha-hydroxylase activity. Cholesterol gallstones are frequently found in ascorbic acid-deficient guinea pigs. Risk factors for cholesterol gallstones in humans include obesity, aging, estrogen treatment, pregnancy and diabetes. Plasma ascorbic acid levels are reduced in these groups. Vegetarian diets, which typically have high ascorbic acid contents, protect against gallstones. Since ascorbic acid effects the rate-limiting step in the catabolism of cholesterol in the guinea pig and many human risk groups for cholesterol gallstones are associated with reduced ascorbic acid levels, ascorbic acid may play a contributory role in human gallbladder disease.     

Dietary carbohydrate and atherosclerosis

Epidemiologic evidence indicated a relationship between refined sugar intake and increased serum cholesterol levels and atherosclerotic heart disease, which resulted in a series of human and animal experiments examining this relationship. Sucrose and fructose were found to be more atherogenic in rabbits and baboons when fed as part of a semipurified diet. However, serum lipid levels were not always elevated when more severe atherosclerosis was present. Human studies generally observed increases in serum triglycerides and, less consistently, serum cholesterol in response to substitution of sucrose for starch or glucose. These differences in lipid levels and experimental atherosclerosis are thought to arise from 1) increased endogenous triglyceride synthesis, present in serum as very low-density lipoproteins; 2) impaired clearance of these lipoproteins; 3) slowed turnover of cholesterol into bile acids; and 4) possible changes in aortic connective tissue metabolism.     

Pathophysiology of gallstone formation

There are two types of gallstones: cholesterol and pigment stones. The pathogenesis is divided into three phases: supersaturation, nucleation and stone growth. Hypersecretion of biliary cholesterol, crystallization promoting and inhibiting factors, gallbladder hypomotility, arachidonyl lecithin, prostaglandins, mucin and calcium play an important role in the formation of gallstones. For the formation of pigment stones a decreased secretion of biliary acids, an increased secretion of unconjugated bilirubin into the bile and an infection of the biliary tract are the most important causative factors.     

Decreased fecal bile acid output in patients with coronary atherosclerosis

In most patients with atherosclerosis, the underlying metabolic derangement remains undefined. Animal experiments have suggested that the ability to produce and excrete large amounts of bile acids may be an adaptation mechanism to cholesterol overload protecting against the atherogenic effects of cholesterol. However, there are very few data on bile acid excretion in human atherosclerosis. In the present study, we have investigated fecal bile acid secretion in subjects with and without coronary artery disease. The target group consisted of 30 patients with proven coronary artery disease and the control group consisted of 27 matched subjects without clinical or laboratory evidence of coronary atherosclerosis. Fecal bile acids were measured by gas-liquid chromatography from 24-hr stool collections under a controlled diet. The patients excreted significantly less bile acids than the controls (325+/-135 vs. 592+/-223 mg/day, respectively, p < 0.0001). The difference was primarily due to a reduced excretion of secondary bile acids. Less than 50% of deoxycholate was excreted by patients (180+/-81 mg/day) as compared to controls (367+/-168 mg/day, p < 0.0002), while lithocholic acid excretion was 111+/-62 mg/day in patients vs. 190 +/-70 mg/day in controls (p < 0.005). The fecal output of the two primary bile acids, cholic and chenodeoxycholic acid, did not differ significantly between patients and controls. The fecal output of total bile acids correlated with that of both secondary bile acids in patients as well as in controls. These findings suggest that patients with coronary heart disease are unable to excrete adequate amounts of bile acids to rid themselves of excess cholesterol, even if they are able to maintain a plasma cholesterol level comparable to that of healthy controls.     

Impaired absorption of cholesterol and bile acids in patients with an ileoanal anastomosis

BACKGROUND: No data exist on cholesterol absorption in patients with an ileoanal anastomosis (IAA). AIMS: To study cholesterol absorption and its effects on cholesterol and bile acid metabolism in patients with an IAA. PATIENTS AND METHODS: Cholesterol absorption, and serum, biliary, and faecal lipids were studied in 24 patients with an IAA and 20 controls. RESULTS: Fractional cholesterol absorption was significantly lower in the patients (36% versus 47% in controls). Surprisingly, the calculated intestinal influx of endogenous cholesterol was reduced so that the absolute absorption of cholesterol was decreased; elimination of cholesterol as faecal neutral steroids remained normal. Thus, the slightly increased cholesterol synthesis was mainly due to increased faecal bile acid excretion, which, in turn, was associated with reduced absorption and biliary secretion of bile acids. Serum total and low density lipoprotein (LDL) cholesterol and LDL triglycerides were lower in the patients. Molar percentage and saturation index of biliary cholesterol were slightly higher in patients with an IAA. Proportions of secondary bile acids in bile and faeces were diminished, and faecal unidentified bile acids were higher in patients. CONCLUSIONS: Cholesterol absorption is significantly impaired in patients with an IAA, and is closely related to changes in serum and biliary lipids observed in these patients.     

Lithogenic diet and gallstone formation in mice: integrated response of activities of regulatory enzymes in hepatic cholesterol metabolism

Supersaturation of bile with cholesterol is a prerequisite of the development of gallstones. With the intention to study the integrated response of enzymes regulating hepatic cholesterol metabolism during gallstone formation we used an established model for the induction of cholesterol gallstone disease in mice. Ten mice were fed on a lithogenic diet containing 10 g cholesterol/kg and 5 g cholic acid/kg for 8 weeks and were compared with ten mice fed on a standard pellet diet. Cholesterol crystals or gallstones developed in 90% of gallbladders in treated mice. The lithogenic diet had an inhibitory effect on the rate-limiting enzyme of cholesterol biosynthesis, hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (EC 1.1.1.88) activity, 39.6 (SEM 2.8) v. 171.0 (SEM 47.3) pmol/min per mg protein. Cholesterol 7 alpha-hydroxylase (EC 1.14.13.17) activity, regulating bile acid synthesis, was decreased by 80%, and this was assumed to be due to cholic acid in the diet. The cholesterol-enriched diet also induced a tenfold increase in cholesterol esterification rate in the liver, i.e. acyl-CoA:cholesterol acyl transferase (ACAT; EC 2.3.1.26) activity. The total, as well as esterified, cholesterol contents of liver homogenates were significantly higher in cholesterol- and cholic acid-treated mice and correlated well with the ACAT activity (rs 0.72 (P < 0.005), and rs 0.68 (P < 0.01) respectively). A significantly higher ACAT activity was obtained in mice given cholesterol and cholic acid even when the enzyme was saturated with exogenous cholesterol, thus indicating an increased amount of the enzyme. The formation of gallstones is dependent on a delicate balance between lithogenic factors (increased absorption of cholesterol and reduced secretion of bile acids) and defence mechanisms (decreased synthesis and increased esterification of cholesterol). In the specific animal model studied here the two defence mechanisms cannot compensate for the increased absorption of cholesterol and the reduced synthesis of bile acids.     

A simplified procedure for the isolation of bile acids from serum based on a batch extraction with the non-ionic resin--Amberlite XAD-7

A simple and reproducible method using the non-ionic resin, Amberlite XAD-7, for the isolation of bile acids from serum by a batch procedure is described. Recoveries were greater than 95% for the non-sulphated bile acids and greater than 70% for the sulphate esters of bile acids. By using 1 g of resin, recoveries were independent of the mass (0.1-5 mumol) of the bile acid present. Up to 35 samples a day can be extracted without requiring dedication of the operator. When serum extracts were analysed by the 3alpha-hydroxysteroid dehydrogenase procedure for estimation of bile acids, virtually all the background fluorescence was eliminated. These extracts were also suitable for gas liquid chromatography, thin layer chromatography, and radioimmunoassay.     

Relationship between biliary and serum bile acids and response to ursodeoxycholic acid in patients with primary biliary cirrhosis

OBJECTIVE: Ursodeoxycholic acid (UDCA) improves liver biochemistries and enriches the bile with UDCA in patients with primary biliary cirrhosis. The aim of this study was to determine whether the degree of enrichment of bile correlated with that of serum and whether either of these measures correlated with improvement in measures of liver disease. METHODS: In a randomized study, biliary and serum bile acid analyses were performed at entry and after 2 yr of UDCA or placebo. RESULTS: The percentage of ursodeoxycholic acid in bile increased by 42% in the UDCA group (n = 61) compared with 8% in the placebo group (n = 57) (p < 0.0001). Measurement of serum bile acids in 32 patients (18 ursodeoxycholic acid, 14 placebo) indicated that at 2 yr, ursodeoxycholic acid comprised 65% of serum bile acids in the treated group and 7% in the placebo group. Agreement between bile and serum was fair (r = 0.75, p < or = 0.00002) because in some patients, plasma but not biliary bile acids were enriched with UDCA. Changes in biliary ursodeoxycholic acid correlated significantly but weakly with the changes in serum alkaline phosphatase, AST, bilirubin, and in Mayo risk score. Correlations between changes in serum bile acid composition and biochemical measures of disease activity were even weaker. CONCLUSION: The measurement of biliary bile acids is superior to that of serum bile acids for assessing the compliance and changes in the circulating bile acids in patients receiving ursodeoxycholic acid for the treatment of primary biliary cirrhosis. Furthermore, measures to further increase the proportion of ursodeoxycholic acid in circulating bile acids should be explored.     

Effect of ethynylestradiol on biliary excretion of bile acids, phosphatidylcolines, and cholesterol in the bile fistula rat

The effects of ethynylestradiol on endogenous bile acids, their capacity to conjugate and excrete intravenously infused cholic acid, the concentrations of biliary cholesterol and lecithin, and the individual molecular species of phosphatidylcholine have been determined in male and female Sprague-Dawley rats. Endogenous biliary bile acids were analyzed by gas-liquid chromatography-mass spectrometry. Eleven bile acids were identified and several minor bile acids, primarily muricholates, could not be completely characterized. After 5 days of treatment with ethynylestradiol (1 mg/kg per day), the percentage of cholic acid decreased and the percentage of 6beta-hydroxylated bile acids, including several monounsaturated species, increased. Ethynylestradiol caused a decrease in bile acid-independent bile flow. Intravenous infusion of cholic acid at a high concentration caused cholestasis in control animals but, after ethynylestradiol treatment, cholestasis developed during the infusion of a much lower concentration of cholate, indicating a lowered threshhold for bile acid-induced cholestasis. In the treated rats, there was a slight increase in excretion of unconjugated endogenous bile acids, and a striking impairment of conjugation of intravenously administered cholic acid. One of the few sex-related differences observed was an increased concentration of biliary phospholipids in untreated male rats. Both phospholipid and cholesterol concentrations in the bile were higher in the treated animals. The molar percentage of cholesterol was always 1-2%, but it was slightly higher in treated animals, especially males. Ethynylestradiol treatment also affected biliary phospholipid by causing a marked increase of phosphatidylcholine species containing palmitic and oleic acid residues and a decrease of species containing stearic and linoleic acid residues. There was no increase in biliary excretion of long chain polyunsaturated species, which might have indicated damage to membranes, in response to ethynylestradiol either alone or with cholic acid infusion. Some of these ethynylestradiol-induced changes in biliary bile acid and lipid excretion are probably peculiar to the rat, but others, such as the increase in molar percentage of cholesterol and cholestasis, may be relevant to disorders in man, especially cholesterol gallstones and idiopathic cholestasis of pregnancy.     

Physiological control of cholecystokinin release and pancreatic enzyme secretion by intraduodenal bile acids

BACKGROUND: The physiological relevance of duodenal bile acids in the control of cholecystokinin release and pancreatic enzyme secretion is still unknown. AIMS: To provide a near physiological situation by perfusing a bile acid mixture mimicking the individual endogenous bile acid composition of the person under investigation. For maximal reduction of endogenous bile output the CCK-A receptor antagonist loxiglumide was infused intravenously. SUBJECTS AND METHODS: Seven healthy volunteers were studied on four different days by a duodenal marker perfusion technique. The individual bile acid composition in duodenal juice and test meal stimulated bile acid output was assessed on day 1. Bile acids were perfused at an amount of 30 or 100% as determined on day 1 in combination with the test meal in the presence or absence of loxiglumide. Pancreatic enzymes, bilirubin, and bile acid output were determined in duodenal juice. Plasma cholecystokinin (CCK) and plasma pancreatic polypeptide (PP) were measured radioimmunologically. RESULTS: Bile acid perfusion did not significantly alter stimulated pancreatic enzyme, bilirubin or bile acid output or plasma CCK. Loxiglumide did not alter basal CCK release but increased test meal stimulated CCK output fourfold (p < 0.05). The addition of bile acids to the test meal at a dose resembling 30% of bile acid output as determined on day 1 prevented this increase. Plasma PP concentration remained unchanged by bile acids and were mostly undetectable during loxiglumide infusion. CONCLUSIONS: The CCK producing cell is under constant suppression by intraduodenal bile acids which cannot be further enhanced by a physiological bile acid mixture. However, removal of duodenal bile acids by inhibition of gall bladder contraction unmasks this suppression leading to a dramatic increase in plasma CCK levels. As little as one third of postprandially released bile acids completely reverse this effect. Bile acids are the most important luminal regulator of CCK release in humans.