ROLE OF GI PHOSPHOLIPIDS IN ULCER PROTECTION

  • Lichtenberger, Lenard M, (PI)

Project: Research projectResearch Project

Description

The mechanism by which the stomach protects itself from autodigestion by
the acid contained within its lumen has not been elucidated to date. In
this proposal we outline a series of experiments to investigate the role of
intrinsic and extrinsic surface-active phospholipids in this protective
mechanism. These studies developed from preliminary findings from our
laboratory which indicated that: 1) amphoteric phospholipids present in
pulmonary surfactant have the capability of increasing the hydrophobic
(non-wettable) property of inert and biological surfaces; 2) these same
surface-active molecules are present in the gastric juice and mucosal
lining; 3) the intact gastric mucosal lining is highly hydrophobic whereas
it is rapidly converted to a wettable surface after the stomach is exposed
to the barrier breakers, aspirin and bile acid; and 4) acid-induced
ulcerogensis and bleeding are markedly reduced if rats are pretreated with
an liposomal suspension of extrinsic surface-active phospholipids. It is
our contention that these surface-active phospholipids are adsorbed onto
the surface of the gastric mucosal surface and in doing so form and
non-wettable hydrophobic layer between the acidic luminal contents and the
gastric epithelium. In the proposed studies we plan to test this
hypothesis by investigating: 1) the relationship between surface
hydrophobicity and the integrity of the "Gastric Mucosal Barrier"; 2) the
localization of the intrinsic surface-active phospholipids within the
gastric mucosa and their cell of origin; 3) the ability of extrinsic
phospholipids to protect against contrasting forms of
experimentally-induced gastric and duodenal ulcer and 4) the possible
mediator role of intrinsic surface-active phospholipids in
prostagladin-induced cytoprotection. The latter possibility seems
particularly appealing since we have obtained preliminary evidence that
prostaglandins acutely stimulate the concentration of surface-active
phospholipids within the rodent gastric mucosa.
StatusFinished
Effective start/end date12/1/8311/30/86

Funding

  • National Institutes of Health

Fingerprint

Ulcer
Phospholipids
Stomach
Gastric Juice
Acids
Cytoprotection
Stomach Ulcer
Duodenal Ulcer
Gastric Mucosa
Bile Acids and Salts
Surface-Active Agents
Aspirin
Rodentia
Suspensions
Mucous Membrane
Epithelium
Hemorrhage

Keywords

  • Medicine(all)