scholarly journals Spectrophotometric determination of the critical micellar concentration of bile salts using bilirubin monoglucuronide as a micellar probe. Utility of derivative spectroscopy

1988 ◽  
Vol 252 (1) ◽  
pp. 275-281 ◽  
Author(s):  
W Spivak ◽  
C Morrison ◽  
D Devinuto ◽  
W Yuey
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Sodium Taurocholate ◽  
Critical Micellar Concentration ◽  
Relative Energy ◽  
Bile Pigment ◽  
Sharp Change ◽  
Derivative Spectroscopy ◽  
Invasive Method ◽  
Sudden Decrease

We have developed a simple biologically non-invasive method for determining the critical micellar concentration (CMC) of bile salts using pure naturally occurring bilirubin IX alpha monoglucuronide (BMG), an important bile pigment present in virtually all mammalian biles. This methodology employs visible absorbance spectroscopy of BMG in bile salts over a range of bile salt concentrations that include the reported CMC. Using 100 microM-BMG in 0.4 M-imidazole buffer at pH 7.8, we calculated that the CMC for sodium taurochenodeoxycholate is between 2.5 and 3.0 mM based on: (1) an abrupt change in lambda max. in this concentration range, (2) a precipitous decrease in the amplitude of the absorbance shoulder at 450 nm, (3) a sudden decrease in the second derivative absorbance of BMG at 400 nm and an increase in absorbance at 470 nm, (4) a sharp change in the 4th derivative absorbance at 375 and 395 nm. In contrast, sodium taurocholate, a bile salt that reportedly does not have a CMC but continuously self-associates over a wide concentration range, exhibited none of these changes. The use of derivative spectroscopy enhances the ability to detect the CMC changes and also indicates the number of BMG species in solution and their relative energy states.

Hepatic bile flow

1984 ◽  
Vol 64 (4) ◽  
pp. 1055-1102 ◽  
Author(s):  
R. C. Strange
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Basolateral Membrane ◽  
Membrane Vesicles ◽  
Critical Micellar Concentration ◽  
Canalicular Membrane ◽  
Receptor Proteins ◽  
Subcellular Organelles ◽  
Golgi Bodies ◽  
Initial Event

The hepatocyte is a polar cell that can remove a variety of molecules from blood and excrete them into bile. This review is primarily concerned with the mechanism of transport of the principal anions--the bile salts--across the sinusoidal membrane, their passage through the cell, and excretion across the canalicular membrane. Clearly much of this process is poorly understood, but the study of the membrane stages should be facilitated by the ability to prepare purified sinusoidal and canalicular membrane vesicles. For example, the relative importance of albumin-binding sites as well as the putative bile salt receptor proteins can be better assessed. It seems likely that although the interaction of bile salts with receptor proteins is important, it is an initial event that puts the bile salt in the correct place for uptake to occur. The driving force for uptake is the Na+ gradient created across the basolateral membrane by the activity of the Na+-K+-ATPase. Within the cell, various modes of transport have been suggested. Several authors emphasize the importance of protein binding of bile salts, either because of their presumed ability to maintain the concentration of these anions in the hepatocyte below their critical micellar concentration or because of their putative role in transport. It is important to understand these aspects of the role of cytosolic proteins for several reasons. Knowledge of the true concentration of free bile salt within the cell should allow estimation of whether the electrochemical gradient is sufficient for bile salts to accumulate in bile without the need for active transport of molecules from the cell into the canaliculus. The compartmental model described by Strange et al. (153) offers one theoretical way of determining the concentration of free bile salt, although the problems inherent in studying amphipath binding to the membranes of subcellular organelles (31) require that the model be reevaluated by the hygroscopic-desorption method. The second role suggested for the cytosolic bile salt-binding proteins is as transport proteins. As discussed in section VI, I think it is unlikely that the proteins identified so far act in this way, and it is more likely that movement occurs by diffusion in free solution. It is also important to determine the possible involvement of subcellular organelles such as Golgi bodies. Little is known of their role in the transport of bile salts or indeed where bile salt micelles are formed.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of intestinal resection on bile salt absorption in dogs

1965 ◽  
Vol 208 (2) ◽  
pp. 363-369 ◽  
Author(s):  
M. R. Playoust ◽  
Leon Lack ◽  
I. M. Weiner
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Enterohepatic Circulation ◽  
Sodium Taurocholate ◽  
Intestinal Resection ◽  
High Fat ◽  
Salt Absorption ◽  
Complete Failure ◽  
Fat Meal

The efficiency of intestinal absorption of bile salts was evaluated by studying the rate of disappearance of radioactivity from the bile of dogs after the intravenous administration of sodium taurocholate-24-C14. Bile was sampled through an indwelling tube in the gall bladder. One day after a high-fat meal normal dogs retained 48% of the radioactivity; dogs with resection of the jejunum retained 48%, whereas those with resection of the ileum retained only 3% in the bile. This is consistent with previous observations that the ileum is the site of bile salt absorption in vitro and in anesthetized animals. Animals with resection of the ileum exhibited significant steatorrhea; however, three-fourths of the ingested fat was absorbed in spite of almost complete failure to absorb bile salts. This indicates that fat and bile salts are not normally absorbed together. Elimination of enterohepatic circulation of bile salts by resection of the ileum contributes to the observed steatorrhea.

Effect of glycodihydrofuisidate on sulfobromophthalein transport maximum in the hamster

1976 ◽  
Vol 231 (6) ◽  
pp. 1875-1878 ◽  
Author(s):  
Y Delage ◽  
M Dumont ◽  
S Erlinger
Keyword(s):  
Bile Salt ◽  
Transport System ◽  
Bile Salts ◽  
Sodium Taurocholate ◽  
Specific Effect ◽  
Biliary Secretion ◽  
Biliary Lipid ◽  
Lipid Secretion ◽  
Dye Transport ◽  
Cholesterol Secretion

The effect on sulfobromophathalein transport maximum (Tm) and biliary lipid secretion of sodium glyco-24,25-dihydrofusicate, a micelle-forming compound secreted into bile, has been studied in the hamster and compared to that of a physiological bile salt, sodium taurocholate. Biliary phospholipid and cholesterol secretion increased both during glycodihydrofusidate and taurocholate administration, an observation which suggest that both compounds increased th biliary secretion of micelle-forming compounds. In contrast, only taurocholate increased sulfobromophthalein Tm into bile, while glycodihydrofusidate administration decreased it. This observation suggests that the increase in sulfobromophthalein Tm observed during taurocholate administration is not the result of micellar sequestration. It could rather be the consequence of a specific effect of bile salts on the dye transport system.

How does bile salt penetration affect the self-assembled architecture of pluronic P123 micelles? – light scattering and spectroscopic investigations

2015 ◽  
Vol 17 (30) ◽  
pp. 19977-19990 ◽  
Author(s):  
Arpita Roy ◽  
Niloy Kundu ◽  
Debasis Banik ◽  
Jagannath Kuchlyan ◽  
Nilmoni Sarkar
Keyword(s):  
Light Scattering ◽  
Bile Salt ◽  
Bile Salts ◽  
Triblock Copolymer ◽  
Sodium Taurocholate ◽  
Sodium Deoxycholate ◽  
The Self ◽  
Spectroscopic Investigations ◽  
Pluronic P123 ◽  
Supramolecular Aggregate

The triblock copolymer of the type (PEO)20–(PPO)70–(PEO)20 (P123) forms a mixed supramolecular aggregate with different bile salts, sodium deoxycholate (NaDC) and sodium taurocholate (NaTC), having different hydrophobicity.

The Effects of Bile Salts on Some Coagulation Components and Related Enzymes

1972 ◽  
Vol 27 (03) ◽  
pp. 594-609 ◽  
Author(s):  
A. M Engel ◽  
B Alexander
Keyword(s):  
Platelet Aggregation ◽  
Bile Salt ◽  
Salt Concentration ◽  
Bile Salts ◽  
Direct Action ◽  
Critical Micellar Concentration ◽  
The Other ◽  
Salt Mixture ◽  
Induced Aggregation ◽  
Activator Complex

SummaryCertain purified bile salts, individually or in a mixture, profoundly affect - either inhibiting or enhancing - the esterolytic activities of thrombin, trypsin, and plasmin, the clotting activity of thrombin, and caseinolysis by trypsin. They also promote SK-induced fibrinolysis and impair FI clottability. These effects are directly related to bile salt concentration but not to the critical micellar concentration.A very unusual effect was observed with deoxycholate and FI : besides inhibiting FI clottability, the salt induces spontaneous gelation. In addition, it binds strongly to the protein, as has been already reported for another plasma protein, albumin, and to a lesser degree, to alpha- and beta-globulins.Noteworthy is the fact that activation of pancreatic juice trypsinogen by thrombin also was increased by prior thrombin exposure to the salts. On the other hand, thrombin-induced platelet aggregation was slightly inhibited by the bile salt mixture, which, when added to PRP moderately inhibited the ADP-induced aggregation. No effect was observed on the conversion of F II in plasma via the thromboplastic mechanism when deoxycholate, or cholate, or glycocholate was added to the system.It is postulated that the bile salt mixture enhances SK-induced fibrinolysis by direct action, either on SK, or on the SK-activator complex, attributable to the detergent properties of the salts.The physiologic and pathologic implications of our results with respect to hemostasis and pancreatitis are discussed.

scholarly journals Biliary protein output by isolated perfused rat livers. Effects of bile salts

1983 ◽  
Vol 210 (2) ◽  
pp. 549-557 ◽  
Author(s):  
S G Barnwell ◽  
P P Godfrey ◽  
P J Lowe ◽  
R Coleman
Keyword(s):  
Plasma Membrane ◽  
Bile Salt ◽  
Bile Salts ◽  
Serum Proteins ◽  
Critical Micellar Concentration ◽  
Rapid Decline ◽  
Perfusion Medium ◽  
Rat Serum ◽  
Membrane Enzymes ◽  
Rat Livers

The output of proteins into bile was studied by using isolated perfused rat livers. Replacement of rat blood with defined perfusion media deprived the liver of rat serum proteins (albumin, immunoglobulin A) and resulted in a rapid decline in the amounts of these proteins in bile. When bovine serum albumin was incorporated into the perfusion medium it appeared in bile within 20 min and the amount in the bile was determined by the concentration of the protein in the perfusion medium. The use of a defined perfusion medium also deprived the livers of bile salts and the amounts of these, and of plasma-membrane enzymes [5′-nucleotidase (EC 3.1.3.5) and phosphodiesterase I], in bile declined rapidly. Introduction of micelle-forming bile salts (taurocholate or glycodeoxycholate) to the perfusion medium 80 min after liver isolation markedly increased the output of plasma-membrane enzymes but had no effect on the other proteins. The magnitude of this response was dependent on the bile salt used and its concentration in bile; there was little effect on plasma-membrane enzyme output until the critical micellar concentration of the bile salt had been exceeded in the bile. A bile salt analogue, taurodehydrocholate, which does not form micelles, did not produce the enhanced output of plasma-membrane enzymes. This work supports the view that the output of plasma-membrane enzymes in bile is a consequence of bile salt output and also provides evidence for mechanisms by which serum proteins enter the bile.

scholarly journals Self-association of unconjugated bilirubin-IX α in aqueous solution at pH 10.0 and physical-chemical interactions with bile salt monomers and micelles

1979 ◽  
Vol 179 (3) ◽  
pp. 675-689 ◽  
Author(s):  
M C Carey ◽  
A P Koretsky
Keyword(s):  
Aqueous Solution ◽  
Absorption Spectrum ◽  
Bile Salt ◽  
Bile Salts ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
Critical Micellar Concentration ◽  
Solvent Mixtures ◽  
Physical Chemical ◽  
Self Association

Spectrophotometric measurements of bilirubin-IX alpha in water and in aqueous/organic solvent mixtures at pH 10.0 as a function of bilirubin-IX alpha concentration (approx. 0.6–400 microM) are consistent with the formation of dimers (KD - 1.5 microM) in dilute (less than 10 microM) aqueous solution and further self-aggregation to multimers at higher concentrations. Added urea (to 10M) and increases in temperature (to 62 degrees C) obliterate the dimer-multimer transition at 10 microM, but added NaCl (to 0.30 M) promotes strong aggregation of dimers over a narrow concentration range, suggesting a ‘micellization’ phenomenon. Concentrations of dioxan or ethanol greater than 60% (v/v) in water were required to obtain the absorption spectrum of bilirubin-IX alpha monomers, suggesting that both hydrophobic and electrostatic (pi-orbital) interactions are involved in stabilizing the dimeric state in water. Micellar concentrations of sodium dodecyl sulphate induced spectrophotometric shifts in the dimer absorption spectrum of bilirubin-IX alpha consistent with progressive partitioning of bilirubin-IX alpha monomers into a relatively non-polar region of the micelles and allowed a deduction of the apparent critical micellar concentration that closely approximated the literature values. The pattern of bilirubin IX alpha association with bile salts is complex, since the absorption spectrum shifts hypsochromically below and bathochromically above the critical micellar concentration of the bile salts. Consistent with these observations, bilirubin IX alpha appears to bind to the polar face of bile salt monomers and to the polar perimeter of small bile salt micelles. At higher bile salt concentrations some-bilirubin-IX alpha monomers partition into the hydrophobic interior of the bile salt micelles. Our results suggest that under physiological conditions the natural conjugates of bilirubin-IX alpha may exhibit similar physical chemical properties in bile, in that dimers, highly aggregated multimers and bile salt-associated monomers may co-exist.

Ileal transposition into the upper jejunum affects lipid and bile salt absorption in rats

1996 ◽  
Vol 271 (4) ◽  
pp. G681-G691 ◽  
Author(s):  
T. Tsuchiya ◽  
T. J. Kalogeris ◽  
P. Tso
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Sodium Taurocholate ◽  
Cholesterol Absorption ◽  
Lymphatic Transport ◽  
Proximal Jejunum ◽  
Ileal Transposition ◽  
Sham Surgery ◽  
Salt Absorption ◽  
Lymph Duct

To determine whether ileal transposition affects absorption and transport of lipids and bile salts, we studied the absorption and lymphatic transport of triglyceride, cholesterol, and sodium taurocholate in rats with the distal quarter of their small bowel transposed to the proximal jejunum and in control rats whose intestines were transected and reanastomosed without transposition. Three weeks after transposition or sham surgery, rats were equipped with duodenal or jejunal and intestinal lymph duct cannulas and then given continuous duodenal or jejunal infusions of lipid emulsion containing triolein (40 mumol/h + [3H]triolein) and cholesterol (7.8 mumol/h + [14C]cholesterol) for 8 h. Lymph lipid output was measured; after 8 h of lipid infusion, luminal and mucosal radioactive lipid distribution was also quantified. Transposition had no effect on triglyceride absorption and transport, but cholesterol absorption and transport were both significantly attenuated in the transposed rats. In a separate study we examined whether ileal transposition would alter the kinetics of bile salt absorption. Six weeks after either transposition or sham surgery, rats were given a duodenal bolus injection of 14C-labeled sodium taurocholate mixed in rat bile, and the output of radiolabeled bile salt through a bile fistula was measured. Appearance of radiolabeled taurocholate was gradual in the control rats, peaking at approximately 90 min after administration. Appearance of labeled bile salt was rapid in the transposed rats, peaking within 60 min after administration. In conclusion, ileal transposition has no effect on triglyceride absorption but attenuates cholesterol absorption and transport, possibly by promoting premature absorption of bile salts.

scholarly journals The inhibitory effect of blood serum on hæmolysis

1923 ◽  
Vol 95 (665) ◽  
pp. 42-61 ◽  
Keyword(s):  
Blood Serum ◽  
Bile Salt ◽  
Bile Salts ◽  
Quantitative Methods ◽  
Sodium Taurocholate ◽  
Marked Change ◽  
Inhibitory Effect ◽  
Haemolytic Activity ◽  
Serum Globulin

It has been recognised for many years that blood serum has an inhibitory effect on the hæmolysis produced by many substances, notably saponin and bile salts. Ransom (1), in 1901, observing that cholesterol inhibits the action of saponin, attributed the inhibitory effect of serum to the contained cholesterol. The quantities of cholesterol used in his experiments are far greater than those which occur in serum, and the experiments are inconclusive for that reason. Bayer (2), in 1907, investigated the inhibitory effect produced by serum on the action of the bile salts. He found that cholesterol has no inhibitory effect, that lecithin produces inhibition, but not in the quantities that occur in blood, and that the proteins of the serum are responsible for the inhibition. He calls attention to the results of von Eisler (3), who states that serum globulin inhibits the action of staphalolysin and of tetanolysin, and also those of von Liebermann, who finds that hæmolysis by soaps is prevented by serum albumin (4). Bayer’s researches are, in the main, confirmed by Sellards (5). The investigations of Ludke (6) and of Scandaliato (7), who found that the inhibitory effect of serum is slightly increased after the injection of bile salts, may be mentioned. The conclusions of these authors are unreliable, since inadequate methods of measuring the amount of inhibition were used. References to various points in connection with the inhibition produced by serum in vivo and in vitro are to be found in the writer’s earlier papers (8, 9, 10). The Nature of the Inhibitory Substances . Before proceeding to the quantitative estimations, it is necessary to know which constituents of serum are responsible for the inhibition of saponin and bile salt hæmolysis respectively. Bayer’s results might be taken as conclusive were it not for two considerations: (1) Bayer filtered most of the solutions of bile salts, and lecithin-bile-salt mixtures, whose hæmolytic power he wished to determine, through a Berkefeld filter, and thereafter tested their hæmolytic activity. He states that this procedure has no effect on the time taken for these solutions to produce hæmolysis. This is a fallacy, for a solution of sodium taurocholate will not pass through a filter paper without losing some of its hæmolytic activity, while passage through a Berkefeld filter causes a very marked change indeed (10). It is therefore not permissible to regard the hæmolytic activity of a solution filtered in this way as identical with, or even corresponding to, the activity of an unfiltered solution; (2) Bayer used very rough quantitative methods—he refers to “slight hæmolysis,” “considerable hæmolysis,” etc., and, accordingly, would be able to detect only very marked degrees of inhibition. The same remark applies to the experiments of Sellards.

scholarly journals Enzymic hydrolysis of sphingomyelin in the presence of bile salts

1980 ◽  
Vol 185 (3) ◽  
pp. 749-754 ◽  
Author(s):  
S Yedgar ◽  
S Gatt
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Sodium Taurocholate ◽  
Absolute Concentration ◽  
Mixed Aggregates ◽  
Sodium Taurodeoxycholate ◽  
Rate Of Hydrolysis ◽  
The Absolute ◽  
Hydrolysis Of ◽  
Low Activity

Sphingomyelin in mixed dispersion with bile salts was hydrolysed by the solubilized sphingomyelinase of rat brain lysosomes. In parallel studies, physical properties of these dispersions were determined. The kinetic curves that described the rate of hydrolysis as a function of increasing concentrations of bile salt were multiphasic. A region of very low activity was followed by an ascending portion, a peak, a descending portion, a trough and a second ascending portion. The positions of the initiation points, peaks and troughs were found to be a function of the respective ratios of the bile salt to sphingomyelin for the detergent sodium taurodeoxycholate, but of the absolute concentration of the detergent for sodium taurocholate. Turbidity studies suggested that hydrolysis of sphingomyelin begins at a bile salt concentration that solubilizes the lipid and incorporates it into a mixed micelle with the detergent. Ultracentrifugation studies suggested that the sizes of the mixed aggregates of detergent and lipid were a function of the ratio of taurodeoxycholate to sphingomyelin, but of the absolute concentration of the bile salt, for sodium taurocholate.

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