ABSTRACT
BACKGROUND: Gastric surfactant is believed to protect gastric mucosa by the hydrophobic properties of its phospholipidic component, which are reflected in the fluorescence polarization of a lipophylic fluorescent probe. The present study aimed to observe the consequences of intragastric administration of 40% ethanol on the physical properties of rat gastric surfactant. METHODS: Fluorescence polarization studies and lipid composition of gastric mucosal surface scrapings were performed. RESULTS: Time course experiments indicated that the ulcerogenic action of ethanol occurred along with a fluidization of the surface scrapings followed by secondary rigidification. The fluidizing effect of ethanol was related to modifications of the molecular dynamics of lipid structures. The rigidifying effect of ethanol was a result of an increase in the cholesterol-triglyceride and cholesterol-phospholipid ratios and an increase in the percent composition of phosphatidyl-ethanolamine of surface scrapings. CONCLUSIONS: The results suggest that alcohol could alter the gastric mucosal barrier by its disorganizing effect on the molecular dynamics of the gastric surfactant. The second rigidifying effect of ethanol could be a part of the damage repair phenomenon.
Subject(s)
Ethanol/pharmacology , Phospholipids/chemistry , Surface-Active Agents/chemistry , Animals , Fluorescence Polarization , Gastric Mucosa/metabolism , Gastric Mucosa/pathology , Intubation, Gastrointestinal , Lipids/analysis , Male , Rats , Rats, WistarABSTRACT
Rat gastric surfactant has been studied by fluorescence polarization, both in a basal state and after an aspirin challenge. Gastric surfactant appeared as a very viscous molecular organisation of phospholipids and was disorganised by low, non ulcerogenic, concentrations of aspirin. The method presented herein allows one to study the human gastric surfactant under physiological and pathological condition and should help in the design of synthetic surfactants for a therapeutical purpose.
