Ability Of Bile Salts Research Articles

Wormlike reverse micelles in lecithin/bile salt/water mixtures in oil

Knowing the ability of water and bile salts to promote the reverse wormlike micelle growth in lecithin/water or lecithin/bile salt mixtures in oil, this work was aimed at elucidating the association properties of the three solutes lecithin, water and the bile salt (BS) sodium deoxycholate in cyclohexane. By systematically changing the fraction of the two additives (i.e.: water and BS) we could identify a region at low additive/lecithin molar ratios where stable wormlike micelle dispersions were formed. Small angle X-ray scattering and oscillatory rheology measurements demonstrated that the ability of bile salt and water to transform the originally spherical lecithin reverse micelles into wormlike micelles and thereby impart to the sample viscoelastic properties is preserved in the three-solute mixture. The results suggest that reverse micelle including both bile salt and water are formed in this system. Reasonably the two primers interact with the same region of the lecithin headgroups and are complementary in altering the packing parameter of the amphiphile to values suitable for the formation of cylindrical aggregates.

Inhibition of calcium oxalate precipitation by bile salts.

Both urinary and biliary stones can contain calcium. Bile salts (BA), which are known to bind Ca2+, are commonly used to dissolve the latter but not the former. The effect of physiologic BA on calcium oxalate (CaOx) precipitation was evaluated by a recently developed method. The Ca2+ binding properties of BA were confirmed by small but significant decreases in pH observed following addition of CaCl2 to bile acids solutions. More importantly, BA inhibited CaOx precipitation with effective concentrations of approximately 10-3 mol/L. The clinical relevance of the latter observation is presently unknown but it is of note that in the same in vitro assay, the activity of BA appeared comparable to that of citric acid, the most common drug for urolithiasis. Although BA do not reach mmol/L levels in urine, they are known to change the physicochemical properties of this fluid, possibly slowing down the crystal growth process. However, the hypothetical therapeutic use of BA in former stone patients would present at least two major problems: (i) hepatotoxicity and (ii) lithogenic activity, due to hyperoxaluria subsequent to increased intestinal absorption of oxalate. The ability of BA in effectively binding calcium ions and in inhibiting the precipitation of CaOx appears of interest from both a physiopathologic and a pharmacologic point of view, even if it does not currently seem exploitable for prophylactic or therapeutic purposes.

Effects of Sodium Citrate on Bile Salt Hemolysis.

In a previous report1 we observed an increase in toxicity of bile salts∗ injected intraperitoneally into the white mouse when sodium citrate was added. In the present study the effects of varying dilutions of bile salts and sodium citrate on human blood cells in vitro have been observed.When bile salts are added to red blood cells of different individuals and allowed to stand at room temperature for 18 hours, hemolysis occurs through dilutions of 1:200 to 1:6400. The bloods of 100 undiagnosed individuals were examined in order to determine their susceptibility to bile salt hemolysis. The large variation in ability of bile salts to hemolyse different bloods is independent of changes due to age of cells, and independent of the temperature and humidity under which the cells are kept.When sodium citrate is added to bile salts, hemolysis of red cells takes place in higher dilutions of the bile salts than when the bile salts per se are employed and the dilution at which hemolysis takes place depends upon the co...