Bile salt-induced increases in duodenal brush-border membrane proton permeability, fluidity, and fragility

Journal Article · Tue May 01 00:00:00 EDT 1990 · Digestive Diseases and Sciences; (USA)

DOI:https://doi.org/10.1007/BF01540406· OSTI ID:6772851

Zhao, D L; Hirst, B H ^[1]

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1. Univ. of Newcastle upon Tyne Medical School (England)

Rabbit duodenal brush-border membrane vesicles were treated in vitro with deoxycholate, glycodeoxycholate, or taurodeoxycholate. Intravesicular (14C)glucose space at equilibrium, 0.54 microliters/mg protein, was reduced by exposure to the three bile salts in a concentration (0.1-5.0 mM)-dependent manner, equatable with increased membrane fragility. Net proton permeability (Pnet), determined by acridine orange fluorescence quenching, was increased from 6.3 x 10(-4) cm/sec in untreated vesicles, by approximately 120, 150, and 170%, by treatment with bile salts at 0.1, 0.5 and 1.0 mM, respectively. The three bile salts were equipotent. The increases in membrane fragility and Pnet were not accompanied by significant increases in membrane fluidity, as assessed from steady-state and time-resolved diphenylhexatriene fluorescence anisotropy. The data demonstrate direct effects of bile salts on duodenal apical membrane fragility and proton permeability that are likely to be early events in bile salt-induced mucosal damage.

• OSTI ID: 6772851
• Journal Information: Digestive Diseases and Sciences; (USA), Vol. 35:5; ISSN 0163-2116
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BILE ACIDS
BIOLOGICAL EFFECTS
CELL MEMBRANES
PERMEABILITY
DIGESTIVE SYSTEM DISEASES
PATHOGENESIS
CARBON 14 COMPOUNDS
FLUORESCENCE
PROTONS
RABBITS
TRACER TECHNIQUES
ANIMALS
BARYONS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
DISEASES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LUMINESCENCE
MAMMALS
MEMBRANES
NUCLEONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
STEROIDS
STEROLS
VERTEBRATES
550901* - Pathology- Tracer Techniques