Dynamic laser light scattering studies of the micelle to vesicle transition in model and native bile.

Abstract

Using quasielastic light scattering, we investigated the formation of vesicles produced spontaneously by diluting a mixed micellar solution of bile salt and lecithin beyond the micellar phase boundary. The vesicles were nearly monodisperse, and their size varied between 120 to 500 A depending upon the dilution conditions. A systematic study of the dependence of the vesicle size upon the bile salt and lecithin concentration was made and interpreted in terms of a simple equilibrium model. Likewise, the particle size distribution in native bile obtained from the dog was studied. A comparison of the dilution effect on native bile and on model bile of identical biliary lipid composition provides unambiguous evidence for micellar aggregates and the occurrence of a micelle to vesicle transition in native bile.