Ioc. Thompson et al., A comparative light-microscopic, electron-microscopic and chemical study of human vaginal and buccal epithelium, ARCH ORAL B, 46(12), 2001, pp. 1091-1098
The scarcity of sizeable specimens of normal oral mucosa for experimental p
urposes has hampered research on oral epithelium. Because large specimens o
f viable human vaginal mucosa are readily available and because vaginal and
buccal epithelia are microscopically similar, vaginal mucosa has been used
successfully to establish a human cyst model in experimental animals. The
ultrastructure and distribution of keratin filaments in these epithelia are
also similar, as is their permeability to water and a number of chemical s
ubstances. Therefore, if vaginal mucosa could be substituted for buccal muc
osa it would expedite research on the epithelium of buccal mucosa, To stren
gthen further the concept that vaginal epithelium could replace buccal epit
helium in certain experimental studies, the thickness of these epithelia, t
heir patterns of surface keratinization, the presence or absence of interce
llular lipid lamellae and their lipid contents were now compared. Thirty-th
ree specimens of vaginal mucosa from postmenopausal women and 36 of buccal
mucosa were investigated. To compare the thickness of the epithelial layers
the number of cell layers in sections of 20 vaginal and 20 buccal mucosal
specimens were counted in the three thickest and three thinnest regions of
each specimen. Surface keratinization was evaluated on sections stained wit
h the Picro-Mallory method. To demonstrate lipid lamellae two vaginal and t
wo buccal mucosa specimens were examined electron microscopically after nor
mal fixation and postfixation in ruthenium tetroxide, Following solvent ext
raction of 11 vaginal and 14 buccal epithelia, quantitative lipid analyses
were performed using thin-layer chromatography. No statistically significan
t differences were found between the maximum and minimum number of epitheli
al cell layers. The patterns of surface keratinization and the distribution
and appearance of the lipid lamellae in the intercellular spaces were simi
lar. The lipid composition of the two epithelia corresponded, except for th
e cholesterol esters and glycosylceramides, which were higher in buccal epi
thelium. Ceramides for vaginal epithelium and triglycerides for buccal epit
helium were not determined. Based on structural similarities, a similar lip
id composition and earlier findings, it is concluded that vaginal epitheliu
m can be used as a substitute for buccal epithelium in certain in vitro, an
d possibly for in vivo, studies. (C) 2001 Elsevier Science Ltd. All rights
reserved.