Thermodynamic and molecular basis for dissimilar cholesterol-solubilizing capacities by micellar solutions of bile salts: cases of sodium chenodeoxycholate and sodium ursodeoxycholate and their glycine and taurine conjugates

Biochemistry ◽  
1981 ◽  
Vol 20 (12) ◽  
pp. 3637-3648 ◽  
Author(s):  
Martin C. Carey ◽  
Jean Claude Montet ◽  
Michael C. Phillips ◽  
Marcia J. Armstrong ◽  
Norman A. Mazer
Keyword(s):  
Molecular Basis ◽  
Bile Salts ◽  
Micellar Solutions ◽  
Sodium Chenodeoxycholate

scholarly journals A study of the physicochemical interactions between biliary lipids and chlorpromazine hydrochloride. Bile-salt precipitation as a mechanism of phenothiazine-induced bile secretory failure

1976 ◽  
Vol 153 (3) ◽  
pp. 519-531 ◽  
Author(s):  
M C Carey ◽  
P C Hirom ◽  
D M Small
Keyword(s):  
Bile Salt ◽  
Bile Salts ◽  
Water Soluble ◽  
Molar Ratio ◽  
Micellar Solutions ◽  
Membrane Phospholipids ◽  
Chlorpromazine Hydrochloride ◽  
Physicochemical Interactions ◽  
Cationic Detergents

Since chlorpromazine hydrochloride [2-chloro-10-(3-dimethylaminopropyl)-phenothiazine hydrochloride] is commonly implicated in causing bile-secretory failure in man and is secreted into bile, we have studied the physicochemical interactions of the drug with the major components of bile in vitro. Chlorpromazine hydrochloride molecules are amphiphilic by virtue of possessing a polar tertiary amine group linked by a short paraffin chain to a tricyclic hydrophobic part. At pH values below the apparent pK (pK'a 7.4) the molecules are water-soluble cationic detergents. We show that bile salts in concentrations above their critical micellar concentrations are precipitated from solution by chlorpromazine hydrochloride as insoluble 1:1 salt complexes. In the case of mixed bile-salt/phosphatidylcholine micellar solutions, however, the degree of precipitation is inhibited by the phospholipid in proportion to its mole fraction. With increases in the concentration of chlorpromazine hydrochloride or bile salt, micellar solubilization of the precipitated complexes results. Sonicated dispersions of the negatively charged phospholipid phosphatidylserine were also precipitated, but dispersions of the zwitterionic phospholipid phosphatidylcholine were not. Chlorpromazine hydrochloride efficiently solubilized these membrane phospholipids as mixed micellar solutions when the drug:phospholipid molar ratio reached 4:1. Polarizing-microscopy and X-ray-diffraction studies revealed that the precipitated complexes were amorphous and potentiometric studies confirmed the presence of a salt bond. Some dissociation of the complex occurred in the case of the most polar bile salt (Ks 0.365). As canalicular bile-salt secretion determines much of bile-water flow, we propose that complexing and precipitation of bile salts by chlorpromazine hydrochloride and its metabolites may be physicochemically related to the reversible bile-secretory failure produced by this drug.

The endothermic nature of the binding of anionic bile salts to a cationic adsorbent

2002 ◽  
Vol 80 (1) ◽  
pp. 89-93 ◽  
Author(s):  
Celia K Williams ◽  
William C Galley ◽  
G Ronald Brown
Keyword(s):  
Bile Salt ◽  
Thermodynamic Parameters ◽  
Driving Force ◽  
Bile Salts ◽  
Cationic Polymer ◽  
Langmuir Equation ◽  
Enthalpy Change ◽  
Polymer Sorbents ◽  
Sodium Chenodeoxycholate ◽  
Increasing Temperature

The binding of a hydrophobic bile salt, sodium chenodeoxycholate, by a polyacrylamide with N,N,N-trimethylammonium dodecyl chloride (QPDA12) pendant groups was studied to evaluate the thermodynamic parameters associated with the binding. The Langmuir equation was used in interpreting the data obtained from HPLC measurements. An increase in binding affinity was observed with increasing temperature indicating that the driving force for binding is derived from an increase in entropy (ΔS° = 253 J mol–1 K–1) despite the positive, or unfavourable, enthalpy change (ΔH° = 53 kJ mol–1). The positive thermodynamic parameters associated with the binding suggest that the disruption of hydrophobic and (or) ionic hydration associated with the bile salts and cationic polymer is the driving force for the binding.Key words: bile salts, endothermic binding, polymer sorbents, solvent randomization.

scholarly journals Absorption of d-α-Tocopherol Solubilized in Micellar Solutions of Various Bile Salts by Rat Small Intestine

1991 ◽  
Vol 40 (5) ◽  
pp. 400-405 ◽  
Author(s):  
Minoru UENO ◽  
Yukiyoshi JYONOSHITA ◽  
Shuichi NAGAKURA ◽  
Seiji SUZUKI ◽  
Hiroki ITOH ◽  
...  
Keyword(s):  
Small Intestine ◽  
Bile Salts ◽  
Rat Small Intestine ◽  
Micellar Solutions

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

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