Some aspects of the regulation of ciliary activity in mammalian somatic cells.

Ciliated cortices isolated from rabbit trachea or oviduct can be reactivated with MgATP (2.4 mM, approx). We analyzed the effects of varying concentrations (0.1-100 mM) of Ca2+ and Mn2+ on the number of cortices which reactivated, as a percentage of the controls. Although reactivation can be inhibited at approximately 10(-2) M cation, we believe that this inhibition might be the result of decreasing MgATP due to competition by Ca2+ and Mn2+ for ATP cation binding sites, rather than cation interactions with the axoneme proper. In addition, whole isolated ciliated cells were obtained from trachea or oviduct by a simple, one step pronase digestion. These cells were incubated with the calcium ionophore A23187 in the presence of 2 mM Ca2+. Inhibition of ciliary activity in 50% of the cells did not occur until about 60 min of incubation. It is believed that what we have observed is cell toxicity rather than a direct effect on the cilia.