LUV's lipid composition modulates diffusion of bile acids

Citation
M. Hofmann et al., LUV's lipid composition modulates diffusion of bile acids, CHEM PHYS L, 110(2), 2001, pp. 165-171
Citations number
29
Categorie Soggetti
Biochemistry & Biophysics
Journal title
CHEMISTRY AND PHYSICS OF LIPIDS
ISSN journal
00093084 → ACNP
Volume
110
Issue
2
Year of publication
2001
Pages
165 - 171
Database
ISI
SICI code
0009-3084(200104)110:2<165:LLCMDO>2.0.ZU;2-6
Abstract
Large unilamellar vesicles were prepared from phosphatidylcholine (PC), sph ingomyelin (SM), cholesterol (Chol) and cardiolipin (CL) by an extrusion te chnique (LUVETs). Diffusion of the more hydrophobic lithocholic acid (LCA) and the less hydrophobic chenodeoxycholic acid (CDCA) was investigated by u sing the pyranine fluorescence method. Membrane permeability was studied by measuring the inclusion of carboxyfluoresceine (CF) into the lipid vesicle s, and membrane fluidity was determined with diphenylhexatriene (DPH) and t rimethylammonium-diphenylhexatriene (TMA-DPH). All results indicate that, C DCA compared to LCA, exhibits a significantly better penetration into vesic les containing SM. LCA penetrates better into vesicles containing cholester ol. Small amounts of CL influenced the diffusional properties of CDCA more than those of LCA. Since Lamcharfi et al. (1997a) Euro. Biophys. 25, 285-29 1 have observed differences in the conformational forms of CDCA and LCA in solution, it is suggested that the diffusion rate of bile acids through (mo del-)membranes is not only dependent on hydrophobicity, but also on bile ac id di-(poly-)meric associations and on membrane-lipid composition. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.