The permeability of hyperplastic oral epithelium

Abstract

An epithelial hyperplasia is one of the reactions of skin and oral mucosa to chemical and mechanical insult. It is usually assumed that this reaction produces a more effective epithelial harrier, but there is no information as to whether a less permeable (issue results. To examine this question, hyperplasia was induced in the cheek pouches of hamsters by either chemical treatment with 0.0025% TPA in acetone or by mechanical abrasion with a rotating mop; untreated hamsters served as controls. The animals were killed and the cheek pouches were removed, mounted in diffusion chambers and the permeability to labelled water and horseradish peroxidase (IIRPO) determined. The results showed that higher values were obtained for the permeability constant of hyperplastic epithelia than for that of control tissue, suggesting that an increased epithelial thickness is not necessarily associated with an improved permeability barrier function. The presence of an inferior barrier layer in hyperplastic epithelia may be related to the increased rate of turnover of this tissue.

The effect ofCandida albicanson the permeability of rat palatal epithelium: an ultrastructural and biochemical study

“…The presence of a permeability barrier to the passage of lanthanum could be demonstrated in healthy rats; a finding in agreement with that of Squier and colleagues [21][22][23]. However, the maintenance of an epithelial barrier in the presence of an oral prosthesis has not been demonstrated previously.…”

“…The permeability barrier can be demonstrated ultrastructurally by the use of electron-dense materials such as lanthanum nitrate [23]. Hyperplasia, induced by turpentine or mild trauma has been shown to affect the permeability of oral epithelium [23]. No reports have been traced concerning the effects of infection on barrier function.…”

“…Healthy palatal epithelium has barrier properties which prevent the ingress of water and water-soluble compounds, and toxins or other deleterious substances [14]. The permeability barrier can be demonstrated ultrastructurally by the use of electron-dense materials such as lanthanum nitrate [23]. Hyperplasia, induced by turpentine or mild trauma has been shown to affect the permeability of oral epithelium [23] [ 18] was used for this purpose.…”

“…The permeability barrier can be demonstrated ultrastructurally by the use of electron-dense materials such as lanthanum nitrate [23]. Hyperplasia, induced by turpentine or mild trauma has been shown to affect the permeability of oral epithelium [23] [ 18] was used for this purpose. In addition, it was decided to analyse qualitatively oral epithelial transudates to determine their nature and resemblance to serum.…”

Anatomy and Physiology of the Oral Mucosa

“…Permeation studies with horseradish peroxidase [5] and lanthanum nitrate [6] have shown that the flattened superficial layers constitute the major barrier, while the lower layers are relatively permeable. This is true in both keratinized and nonkeratinized epithelium, suggesting that keratinization does not offer as much resistance to buccal drug permeation as once thought.…”