Studies on the Permeability of Human Oral Mucosa III. The Permeability of Dry Buccal Mucosa to Water, Sodium and Potassium

Abstract

The loss of water, sodium and potassium from human buccal mucosa during temporary suspension of salivary secretion has been studied by analysing the content of filter paper discs applied to the mucosa in 12 young persons, 11 with normal mucosa and 1 with bilateral leu-koedema. With continuous sampling with a cytological filter interposed between the mucous membrane and the filter paper, the material showed a uniform increase in weight, whilst corresponding samples with direct contact with the mucosa showed a variable weight level with initially increased, but gradually falling values. The increase in weight originated partly from a continuous outward diffusion of water, and partly from local fluid accumulations in the epithelium. The diffusional loss was negatively correlated with the surrounding air humidity and showed significantly higher values than the corresponding loss through palatal epithelium.

The analyses indicated that the local accumulations of fluid in the epithelium were the main reason for the electrolyte content of the samples. The investigation showed no signs of an outward transport of sodium and potassium through the buccal epithelium. The observations are briefly discussed against the background of an equilibrium between the superficial layer of the buccal epithelium and saliva.