Mucociliary frequency of frog palate epithelium.

The depleted frog palate epithelium is extensively used as a model for studying the transport velocity of mucus. It is speculated that the epithelium can be depleted of endogenous gel mucus without affecting the ciliary frequency, provided the sol phase where the cilia beat remains present. To control the stability of the ciliary frequency during the measurement of mucous transport velocity, we have used a photoelectric method for measuring mucociliary frequency and have carried out experiments in excised frog palates in different areas and at successive stages of depletion. From the distribution function of the mucociliary frequency obtained by the fast Fourier transform analysis, we have calculated the mean frequency (Fm) and the dispersion of the spectrum defined as spectrum width (Sw). Fm and Sw are similar in different areas throughout the zone selected for mucous transport velocity measurements. A significant decrease in Fm (21%) and parallel increase in Sw (22.8%) are observed at the stage of depletion, but the values return to normal when a drop of frog's mucus is added. These results suggest that the depleted frog palate is a good model for studying the in vitro transport rate of mucus and investigating the effects of mucus on ciliary frequency.