Ca2+-dependent hormonal stimulation of ciliary activity.

It has been demonstrated that calcium modulates ciliary activity in protozoa and also in epithelial cilia of the mussel gill. Changes in the frequency of ciliary beat in the oviduct of the salamander have also been associated with movement of Ca2 across the cell membrane. However, the control of ciliary activity in mammals is poorly understood and the function of calcium in mammalian cilia and its role in coupling hormonal effects to changes in ciliary activity have been only preliminarily investigated. The evidence presented here suggests that the stimulus-response coupling of the stimulating effect of prostaglandin E2 (PGE2) on ciliary activity of the rabbit oviduct is carried out by release of intracellular Ca2+.