Effect of Ca2+ on the ciliary beat frequency of skinned dog tracheal epithelium.
Beat frequency of dog tracheal ciliated epithelium was measured using a profile projector and a photomultiplier. The preparation, treated with 50 micrograms/ml of saponin for 15 min, lost osmotic behavior and the ciliary beat came to depend on externally applied MgATP2- indicating that ciliated epithelium is skinned with saponin. Beat frequency of skinned cilia did not increase with Ca2+ in 0.1 mM MgATP2- with no ATP-regenerating system. Under 4 mM Mg ATP2- the beat frequency increased with an increase in Ca2+ from 0.3 to 10 microM, although a marked beat continued in the virtual absence of Ca2+ sensitivity and maximum beat frequency increased with the addition of 2.4 microM calmodulin. The effect of calmodulin inhibitor (W-7) on skinned preparations was somewhat weaker than that on intact ones. We concluded that Ca2+, within the physiological range of concentrations, directly activated the ciliary proteins and increased the ciliary beat frequency. The addition of calmodulin augments the effect of Ca2+ but the basal beat frequency is not Ca2+ dependent.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002923:Cilia / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D004848:Epithelium / Q000187:drug effects; D012503:Saponins / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects
D002147:Calmodulin; D012503:Saponins; D013449:Sulfonamides; C017967:W 7; D000255:Adenosine Triphosphate; D002118:Calcium