Lipid compositions of human gastric fluid and epithelium: the role of sulfated lipids in gastric cytoprotection.

ABSTRACT

BACKGROUND: Gastric sulfatide, whose carbohydrate moiety resembles that of the anti-ulcer drug sucralfate, has been shown to play a role in mucosal protection in an experimental ulcer model. To elucidate the functional significance of gastric lipids, precise determination of the lipids in human gastric fluid and epithelium was performed, and the anti-ulcer effects of all lipids in the fluid were measured in mouse ulcer models. METHODS: The lipids in human gastric fluid and epithelium were analyzed by thin layer chromatography and immunostaining, and the anti-ulcer effects of gastric lipids were determined using mouse ulcer models. RESULTS: Human gastric epithelium contained both sulfatide and cholesterol sulfate (CS) as sulfolipids, which were also detected in gastric fluid, showing their stable natures in the gastric fluid. Hemorrhaging in HCl-induced gastric lesions was suppressed in a dose-dependent manner by the administration of sulfolipid-containing liposomes, but suppression of stress ulcers was only accomplished with CS-containing liposomes, ie, not with sulfatide-containing ones, due to the longer retainment of CS than sulfatide in the stomach. CONCLUSIONS: Among the lipids in human gastric fluid, CS was revealed to exhibit a gastroprotective activity, which was more effective than that of sulfatide.