BEATING DYNAMICS OF MAMMALIAN RESPIRATORY CILIA
Abstract
Respiratory cilia of man, rabbit, rat and hamster were studied by high speed cinemicrography and found to have a nonplanar beat, a high amplitude and antilaeoplectic metachronism. This pattern of beating does not differ significantly from beating patterns of non-mammalian cilia. Mammalian respiratory cilia were found to beat from 1/s to 20/s, depending on the temperature. The effective phase occupies 2/5 of the entire beat cycle. The effective stroke is straight, perpendicular to the cell surface and moves through an arc from about 20(DEGREES) to 170(DEGREES). During the mid-effective stroke, the tips of the cilia penetrate the mucus, thereby imparting their force directly to the mucus and propelling it in the direction of the effective stroke. The recovery phase occupies 3/5 of the entire beat cycle. During this phase, the cilium moves back as a flexible rod with a bend being propagated from base to tip. The recovery stroke is slower, curved and inclined to the right of the line of beating. This causes the tip to move backward well below the mucus and therefore does not impede its forward flow. Beating parameters such as ciliary beat frequency, tip velocity, effective wave velocity, recovery wave velocity and wave-length were measured. Cultured ciliated cells were obtained by plating single cells from enzymatic digestion of respiratory mucosa or by explant culture of respiratory mucosa or trachael rings. Ciliary activity was studied using high speed cinemicrography. Normal and abnormal beating was seen on cultured cells. Both epithelial- and fibroblast-like cells had actively beating cilia. Aberrant beating forms were observed in cultures which had a low percentage of ciliated cells or were sparsely ciliated. Aberrancies included planar recovery stroke, cilia beating in different directions on the same cell, cilia stuck together and moving as a unit, and asynchronous beating. Beating parameters were measured on outgrowths from mucosal explants. Isoproterenol, caffeine, theophylline and db-cAMP increased CBF without affecting direction, amplitude, shape or inclination of beat. There was no apparent effect on wavelength, and metachronism remained unchanged. EDTA and EGTA decreased CBF and produced asynchronous beating, planar beating, ciliary arrest and cell separation.
Subject Area
Biology
Recommended Citation
MARINO, MARIA RITA, "BEATING DYNAMICS OF MAMMALIAN RESPIRATORY CILIA" (1982). ETD Collection for Fordham University. AAI8213248.
https://research.library.fordham.edu/dissertations/AAI8213248
