Calcium regulation of ciliary activity in rabbit tracheal epithelial explants and outgrowth.
Ciliated epithelial cells from rabbit trachea were employed to examine the role of Ca2+ in the regulation of ciliary motility. Tracheal explants and outgrowths were maintained in culture, and ciliary frequency was determined using a photomultiplier interfaced with a spectrum analyzer capable of Fast Fourier transform analysis. Relative cellular Ca2+ levels were determined by measuring 45Ca2+ uptake and efflux. Elevated cellular Ca2+, from exposure to 10(-5) M calcium ionophore A23187, led to an increase in ciliary frequency followed by inhibition of motility after prolonged treatment. A decrease in ciliary frequency was observed upon lowering intracellular Ca2+ by exposing the epithelium to 1 mM EGTA. Exposure of ciliated cells to 10(-4) M trifluoperazine resulted in inhibition of ciliary motility, a result suggesting a possible role for calmodulin- or phospholipid-sensitive Ca2+-dependent protein kinases in ciliary function. These results support the hypothesis that intracellular Ca2+ is actively involved in modulating the frequency of ciliary beat.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002923:Cilia / Q000502:physiology*; D004533:Egtazic Acid / Q000494:pharmacology; D004848:Epithelium / Q000648:ultrastructure; D005260:Female; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009068:Movement; D011817:Rabbits; D014132:Trachea / Q000648:ultrastructure; D014268:Trifluoperazine / Q000494:pharmacology
D014268:Trifluoperazine; D000001:Calcimycin; D004533:Egtazic Acid; D002118:Calcium