抄録
The ciliary beating plays a crucial role for the maintenance of healthy airways. The activities of beating cilia are assessed by two parameters, ciliary beat frequency (CBF) and ciliary beat angle (CBA, an index of amplitude). Increases in CBF and CBA enhance the ciliary transport of airways. We measured CBF and CBA using a high–speed video-microscope (500 fps). In cAMP–regulated CBF, a CBF–increase stimulated by cAMP accumulation was controlled to an adequate level by PDE1A (Ca2+–dependent phosphodiesterase 1A) located in the metabolon regulating CBF (outer dynein arm). Increases in CBF and CBA are closely related to the structure of cilium. Carbocistein (CCis, a mucoactive agent) induced a small CBF increase and a large CBA increase mediated via a small elevation of intracellular pH (pHi) and a decrease in intracellular Cl– concentration ([Cl–]i), respectively; an elevation of pHi stimulated by HCO3– entry increased CBF and CBA, and a decrease in [Cl–]i stimulated by Cl– secretion increased CBA, but not CBF. Thus, in airway ciliary cells, CBF and CBA are regulated by interactions between Ca2+ and cAMP signals and also by the cellular events stimulated by both signals.
