Acids biliary

Fig. 7. Comparison of the two different types of extracellular and biliary contrast agents. One monomeric and one dimeric example are illustrated from each type, lopromide and iotrolan (extracellular type) are extremely hydrophilic whereas iopodinic acid and iotroxic acid (biliary type) are both ionic and very lipophilic... 

Composition.—Chiefly consists of olein, palmitin, and stearin, with small quantities of free butyric and acetic acids, biliary constituents, gaduine and other peculiar substances, iodine, bromine, sulphur, free phosphorus, and about one per cent, of mineral salts. 

Harold et al. (114) also showed that the acidic biliary metabolites derived from J -cholestenone-C in the bile fistula rat appeared in fractions associated with trihydroxy and dihydroxy bile acids. Recrystallization with carrier cholic acid virtually eliminated the metabolite from this acid. By similar technique the C-metabolite in the dihydroxy fractions was shown to differ from deoxycholic and chenodeoxycholic acids however, in the latter case conversion to the diacetate was necessary to remove the C. 

Although vitamin K is a fat soluble vitamin, only little stores are found in the body which have to be refilled permanently via dietary input. The role of vitamin K derived from bacteria in the colon is controversely discussed, as the concentration of biliary acids for the resorption the fatsoluble vitamin K is very low in the colon. In addition, only diseases of the small intestine lead to a deficit in vitamin K concentration which cannot be restored by K2 production of colonic bacteria. However, watersoluble vitamin Ks can be resorbed by the colonic mucosa. Maybe because of the little stores for vitamin K, the process of vitamin K-dependent carboxylation of proteins is part of a cycle with several steps during which vitamin K normally is regenerated (see Fig. 1) and thus can be used several times. 

Gall bladder Various oral cystographic agents, e.g., iopanoic acid Telepaque etc. Anion transport Urich K, Speck U (1991) Biliary excretion of contrast media. Progr Pharmacol Clin Pharmacol 8 307-322... 

The bile acid sequestrants are contraindicated in patients with known hypersensitivity to the drugs. Bile acid sequestrants are also contraindicated in those with complete biliary obstruction. These drags are used cautiously in patients with a history of liver or kidney disease Bile acid sequestrants are used cautiously during pregnancy (Pregnancy Category C) and lactation (decreased absorption of vitamins may affect the infant). 

SEETHARAMIAH G s, CHANDRASEKHARA N (1990) Effect of gamma oryzanol on cholesterol absorption and biliary and fecal bile acids in rats. Ind J Med Res, 92 471-5. 

Finally, the fact that anthocyanins can reach the brain represents a beginning of an explanation of the purported neuroprotection effects of anthocyanins. Anthocyanins may be eliminated via urinary and biliary excretion routes. " The extent of elimination of anthocyanins via urine is usually very low (< 0.2% intake) in rats and in humans, indicating either a more pronounced elimination via the bile route or extensive metabolism. As mentioned earlier, in the colon, non-absorbed or biliary excreted anthocyanins can be metabolized by the intestinal microflora into simpler break-down compounds such as phenolic acids that may be (re)absorbed and conjugated with glycine, glucuronic acid, or sulfate and also exhibit some biological... 

Bilzer, M. and Lauterburg, B.H. (1991). Effects of hypoch-lorous acid and chloramines on vascular resistance, cell integrity, and biliary glutathione disulfide in the perfused rat liver modulation by glutathione. J. Hepatol. 13, 84-89. 

PAS Periodic acid-SchiflF reagent PBA Polyclonal B cell activators PBC Primary biliary cirrhosis PBL Peripheral blood lymphocytes PBMC Peripheral blood mononuclear cells PBN N- e f-butyl-a-phenylnitrone PBS Phosphate-buffered saline PC Phosphatidylcholine... 

Several studies in rats have shown that certain acidic and basic compounds can be actively secreted into the bile. Thus, one might expect to see saturation of the biliary excretion process, although data in humans describing this phenomenon have not, as yet, been reported for orally dosed drugs. 

Bile salt export pump (BSEP gene symbol ABCB11) mediates the biliary excretion of nonconjugated bile salts, such as taurocholic acid, glycocholic acid and cholic acid, and therefore is responsible for the formation of the bile acid-dependent bile flow [97, 98]. Its hereditary defect results in the acquisition of PFIC2, a potentially lethal disease which requires liver transplantation [17, 81, 82, 99]. As discussed in Section 12.5.2, the inhibition of BSEP following drug administration may result in cholestasis. 

Ward et al. [125] investigated the disposition of 14C-radiolabeled primaquine in the isolated perfused rat liver preparation, after the administration of 0.5, 1.5, and 5 mg doses of the drug. The pharmacokinetics of primaquine in the experimental model was dependent on dose size. Increasing the dose from 0.5 to 5 mg produced a significant reduction in clearance from 11.6 to 2.9 mL/min. This decrease was accompanied by a disproportionate increase in the value of the area under the curve from 25.4 to 1128.6 pg/mL, elimination half-life from 33.2 to 413 min, and volume of distribution from 547.7 to 1489 mL. Primaquine exhibited dose dependency in its pattern of metabolism. While the carboxylic acid derivative of primaquine was not detected perfusate after the 0.5 mg dose, it was the principal perfusate metabolite after 5 mg dose. Primaquine was subject to extensive biliary excretion at all doses, the total amount of 14C-radioactivity excreted in the bile decreased from 60 to 30%i as the dose of primaquine was increased from 0.5 to 5 mg. 

Chignard N, Mergey M, Veissiere D, Parc R, Capeau J, Poupon R et al. Bile acid transport and regulating functions in the human biliary epithelium. Hepatology 2001 33(3)496-503. 

In subacute toxicity studies only the highest rifaximin dose (i.e. 100 mg/kg, corresponding to 25 times the therapeutic dose in humans) induced mild toxic effects (like, for instance, acute gastroenteritis) connected to the topical GI action of the drug [59, 255], A dose-dependent increase of the total cholesterol value was recorded in female animals [255], most likely due to an alteration of biliary acid metabolism consequent to the antibiotic effect on gut flora [256]. 

In mammals, phenobarbital and phenytoin increase serum ceruloplasmin concentrations (Aaseth and Norseth 1986). Chronic copper poisoning in sheep is exacerbated when diets contain heliotrope plants (Heliotropium sp., Echium spp., Senecio sp.). Aggravated effects of the heliotrope plants include reduced survival and a twofold to threefold increase in liver and kidney copper concentrations when compared to control animals fed copper without heliotropes (Howell et al. 1991). Rats given acutely toxic doses of 2,3,7,8-tetrachlorodibenzo-para-dioxin had elevated concentrations of copper in liver and kidney because of impaired biliary excretion of copper (Elsenhans et al. 1991). Morphine increases copper concentrations in the central nervous system of rats, and dithiocarbam-ates inhibit biliary excretion (Aaseth and Norseth 1986). In human patients, urinary excretion of copper is increased after treatment with D-penicillamine, calcium disodium EDTA, or calcium trisodium diethylenetriamine penta acetic acid (Flora 1991). 

Intestinal absorption of diflubenzuron in laboratory rats, measured as the sum of urinary and biliary excretion, decreases with increasing dose from 50% at a single oral dose of 4 mg/kg BW to 4% at 900 mg/kg BW. Excretion is almost complete after 75 h at that time, up to 4% of the administered dose is recovered from skinned carcasses (Willems etal. 1980). About 80% of diflubenzuron metabolites excreted by rats seem to have the basic diflubenzuron structure intact. Three metabolites are largely excreted as conjugates in the bile. One metabolite, 2,6-difluorobenzoic acid, is excreted largely in urine. Its counterpart, 4-chlorophenylurea, was not present in urine or bile in appreciable quantity, nor was 4-chloroaniline detected (Willems et al. 1980). Lifetime feeding studies of 4-chloroaniline, a relatively common diflubenzuron metabolite, showed no compound-related effects in laboratory mice and rats (Gartrell 1981). 

Studies in experimental animals suggest that biliary excretion of chemicals from the liver may be impaired by mirex or chlordecone (Berman et al. 1986 Curtis and Hoyt 1984 Curtis and Mehendale 1979 Curtis et al. 1979b, 1981 Davison et al. 1976 Mehendale 1976, 1977b, 1977c, 1981b Teo and Vore 1991). Measurement of serum bile acid levels may provide information regarding biliary excretory function. 

Since probenecid is used extensively as an inhibitor of the urinary and biliary excretion of carboxylic, phenolic and sulphonic acids in many other animals, it was of interest to determine if probenecid would inhibit the urinary and/or biliary transport of phenol red in the shark (Table IV). The plasma levels determined at 4 hrs. after administration of phenol red alone or in combination... 

Trautwein, E. A., Rieckhoff, D., Kunath-Rau, A., and Erbersdobler, H. F. (1998). Psyllium, not pectin or guar gum, alters lipoprotein and biliary bile acid composition and fecal sterol excretion in the hamster. Lipids 33, 573-582. 

Digestive system g agonists decrease secretion of stomach acid, reduce gastric motility, and prolong gastric emptying. Pancreatic, biliary, and intestinal secretions are reduced. Intestinal transit is also slowed. Peristaltic movements are reduced, but tone is increased, sometimes causing spasm. As a result, constipation is a frequent problem with opioid use. Bile duct pressure is also increased by opioids. 

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