In a previous study we demonstrated that @entity1 @entity5932 was as permeable to water as was buccal mucosa. Water, however, is a very small molecule with a molecular weight of 18 d. To further explore similarities between these two types of mucosa with respect to permeability, it was decided to investigate the passage of two large, hydrophilic molecules across these epithelia. Specimens of fresh, clinically healthy @entity1 @entity14705 were taken from excised tissue obtained during vaginal hysterectomies and various oral surgical procedures. Seven biopsy materials from each specimen were mounted in flow-through diffusion cells (exposed area, 0.039 cm2), and their permeability to 4.4- and 12-kd @entity2822 -labeled dextrans was determined through use of a continuous flow-through perfusion system. Dextran was detected by means of a fluorospectrophotometric method at excitation and emission wave lengths of 498 and 520 nm, respectively. Specimens were examined histologically before and after permeability experiments, and similarities between vaginal and buccal tissues were verified. No statistically significant differences between the flux values of the 4.4-kd dextran across @entity14705 were found. However, for the 12-kd dextran the flux rate across buccal mucosa was significantly higher than the rate across @entity5932 . These results demonstrate that @entity1 @entity5932 is for practical purposes as permeable as buccal mucosa to 4.4-kd hydrophilic molecules. This further supports the hypothesis that @entity5932 may be a useful model for studying the passage across buccal mucosa of chemical compounds and therapeutic agents that are less than approximately 4.4 kd in molecular mass. For a 12-kd dextran the flux rate across buccal mucosa is significantly higher than the flux rate across @entity5932 , and the model becomes inaccurate.

Penetration of @entity1 @entity14705 by 4.4-kd and 12-kd XXXX -labeled dextrans.

@entity1 :: ('9606', 'Species') :: ['human'] @entity2822 :: ('CHEBI:37926', 'Chemical') :: ['fluorescein-isothiocyanate'] @entity5932 :: ('MESH:C565008', 'Disease') :: ['vaginal mucosa'] @entity14705 :: ('MESH:D007967', 'Disease') :: ['vaginal and buccal mucosa']
@entity2822 :: (CHEBI:37926,Chemical) :: ['fluorescein-isothiocyanate']
