Background: Recently, a hydrophobic layer has been shown by the contact angle method in human gastric biopsy specimens. The aim of this study was to show the existence of a phospholipid-rich layer in the human gastric epithelium and to investigate the influence of Helicobacter pylori on these structures.
Methods: Biopsy specimens from the gastric antrum were obtained during gastroscopy from patients with normal gastric mucosa as well as from patients with H. pylori-positive gastritis for electron microscopical and histological examination. Structures reacting with a phospholipid-selective stain, iodoplatinate were analyzed by electron microscopy and electron-dispersive x-ray microanalysis.
Results: Both methods revealed the morphological existence of a phospholipid-rich zone covering the human gastric epithelial layer. Reaction products could be localized within the cells, at the epithelium closely associated with the surface, and in connection with the mucus. In infected tissue, H. pylori affects iodoplatinate-reactive material within the mucous layer and material covering the epithelium.
Conclusions: The phospholipid-rich zone in the apical region of surface mucous cells is likely to represent an important factor of the gastric protective system in humans. The destruction of this hydrophobic layer may result in a reduction of hydrophobicity giving access to gastric acid.