Bile lipids

Trautwein, E. A., Siddiqui, A., and Hayes, K. C. (1993). Modeling plasma lipoprotein-bile lipid relationships Differential impact of psyllium and cholestyramine in hamsters fed a lithogenic diet. Metabolism 42,1531-1540. 

Results obtained in this way were helpful, but of limited value. The analyses told us whether or not the bile was supersaturated with cholesterol, but did not tell us whether the abnormality was due to too much cholesterol, too few bile acids, too few phospholipids or to some combined defect. The next step, therefore, was to measure the hour-by-hour bile lipid-secretion rates using marker-corrected perfusion techniques. These assume that, in response to the perfusion stimulus (such as an intra-duodenal amino acid mixture), the gallbladder remains tonically contracted throughout and steady-state conditions ensue. 

When the proportion of biliary DCA, expressed as a percentage of total bile acids, was measured in the same three groups of individuals in the Octreotide studies, a similar pattern of results was found to that described above for bile lipids - namely, low values (approximately 12%) in the so-called controls and significantly higher values (approximately 24%) in the two groups of stone carriers. ... 

Cholestasis can lead to a similar occurrence of a broad-/l-band. This results from the presence of lipoprotein X [Lp(X)], which migrates slightly closer to the application point than LDL but cannot be separated from it. Lp(X) is derived from bile lipids including free cholesterol and phospholipids that acquired apolipoproteins after they were released into the blood. However, this Lp(X)-derived broad-jS-band migrates closer to the application point than LDL and can be distinguished from the broad-/l-band of familial dysbetalipoproteinemia (type III). 

This volume of secretion is supplemented in the ductules by ca. 150 ml ductular bile, resulting in a daily production of ca. 600 ml. Bile formation is lower at night than during the day. The most important constituents of the so-called liver bile are the bile acids, phospholipids, proteins, cholesterol and bilirubin. The term bile lipids includes cholesterol, bile salts and phospholipids. The manner in which cholesterol is excreted into the gall bladder is not yet known, nor have any cholesterol-specific transport systems been detected. Cholesterol is primarily broken down into bile acids, (see above) (s. tab. 3.5)... 

Elevation of cholesterol is found in fatty liver, particularly under diabetic metabolic conditions. A rather marked increase in cholesterol can be observed in all forms of cholestasis differentiation between intra- or extrahepatic cholestasis, however, is not possible. This elevation of cholesterol in obstruction is due to an enhanced synthesis of cholesterol in hepatocytes and intestinal walls as well as to the retention of bile lipids. Marked elevations of cholesterol are detectable in primary biliary cirrhosis and in cholesterol storage disease. A pronounced increase in cholesterol is also found in Zieve s syndrome (L. Zieve, 1958). 

P3. Palmer, R. H., and Bolt, M. G., Bile acid sulfates. I. Synthesis oflithocholic acid sulfates and their identification in human bile. /. Lipid Res. 12, 671-679 (1971). 

Turley, S. D., and Dietschy, J. M., Re-evaluation of the 3a-hydroxysteroid dehydrogenase assay for total bile acids in bile. /. Lipid Res. 19, 924-928 (1978). 

Some further examples of the application of TLC may be cited a procedure for two dimensional separation [179] analysis of bile from various species [76] fractionation of bile lipids into groups [128] metabolism [73] and analysis of human faecal bile acids [153 a] quantitative determination of free [203] and bile acid conjugates [202] in serum. 

Analysis of Human Bile Lipids by Gas-Liquid Chromatography Acta Chem, Scand. 14 1006-1010 (1960) CA 56 9267f... 

Fatty Acid Comjosition of Human Bile Lipids... 

Brown AW, Hang J, Dussault PH, Carr TP (2010) Phytosterol esto ccholesterol solubility in model bile. Lipids 45(9) 855-862. doi 10.1007/sll745-010-3456-6... 

BA are a group of compounds characterized by the steroid scaffolding with a carboxyl group located in the side chain. These compounds are the major catabolic products of cholesterol and facilitate either the excretion of bile lipids including cholesterol or the absorption of dietary lipids. 

FXR/RXR activation 0.0229 0.16 16 3/13 Modulate bile, lipid and glucose homeostasis. 

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