Mucociliary transport function and damage of ciliated epithelium

The influence of epithelial damage on mucociliary transport was studied in relation to the amount of mucus. The mucosal epithelium of mucus-depleted frog palate was dissected and mounted on a plastic plate. Mechanical damages were created on the frog mucosa by pressing a different thickness of boards (2, 3, 5, and 8 mm). Two different amounts of frog mucus (7.9 μL [small amount of mucus S-mucus]) and 51.0 μL [large amount of mucus L-mucus]) were applied on the frog mucosa with and without mucosal damage. There was no difference in mucociliary transport rate (MTR) on undamaged frog mucosa between S-mucus and L-mucus. However, on the damaged mucosa, MTR of S-mucus was significantly decreased compared with that of L-mucus. Moreover, capability of mucus transportation across the mucosal damage was significantly lower in S-mucus than in L-mucus. Results indicate that the larger the mucus amount becomes, the more the mucus travels the damaged epithelium. Moreover, MTR of L-mucus was decreased with increasing the degree of epithelial damage. This study indicates that the degree of loss of cilia is an important factor of mucociliary deceleration