Effects of anionic surfactants on hamster small intestinal membrane structure and function: relationship to surface...

Area of Science:

• Gastroenterology
• Membrane Biology
• Biochemistry

Background:

• Anionic surfactants exhibit varying effects on intestinal water transport.
• Surface properties are key determinants of biological activity.
• Erythrocyte lysis serves as a model for membrane interactions.

Purpose of the Study:

• To investigate the relationship between anionic surfactant surface properties and intestinal water transport.
• To elucidate the mechanism by which surfactants alter intestinal function.
• To compare the effects of different classes of bile salts and detergents.

Main Methods:

• In vitro studies using everted hamster jejunal segments.
• In vivo studies on hamster small intestine.
• Erythrocyte lysis assays.
• Surface property measurements (critical micelle concentration, surface tension reduction).
• Histological and electron microscopy analysis.
• Permeability studies using tracers (inulin, dextran, albumin).

Main Results:

• Dose-response inhibition of water transport observed with detergents and dihydroxy bile salts.
• Trihydroxy and tri-keto bile salts did not affect water transport.
• Surfactant effects on water transport paralleled erythrocyte lysis.
• Deoxycholate induced net water secretion and increased mucosal permeability in vivo.
• Biochemical and histological changes included DNA/sucrase release and villus shortening.
• Electron microscopy showed brush border membrane alterations and increased permeability to tracers.
• Taurocholate had no effect on water transport, permeability, or membrane integrity.

Conclusions:

• Surface properties of anionic surfactants are critical for their effects on intestinal water transport.
• Surfactants alter absorptive cell membranes, leading to intestinal secretion and increased permeability.
• The degree of bile salt hydroxylation influences their impact on intestinal function.