[Pharmacologic studies of cultivated human ciliated cells of the upper respiratory tract]

The ciliary frequency was measured in cultivated ciliated human cells of the upper respiratory tract. An attempt was made to influence this isolated system pharmacologically. Previously, contradictory results have been published regarding the effects of parasympathomimetic and sympathomimetic drugs. We investigated the muscarinic agonist carbachol and the beta 2-adrenoreceptor stimulating drug clenbuterol. Carbachol (10(-3) M) did not modify the ciliary frequency in 6 experiments neither at 37 degrees C nor at 24 degrees C, where the basal frequency was reduced. Spiropent (10(-5) M), a pharmaceutical preparation of clenbuterol and lactose, increased the ciliary frequency in 3 experiments. Clenbuterol, tested in the same concentration in 1 experiment, also caused an increase. Lactose was without effect. The secretolytic drug ambroxol did not influence the ciliary frequency. The neuropeptide substance P which causes an increase in ciliary frequency in the respiratory tract of rabbits in vivo, had no effect on isolated human ciliated cells indicating an indirect effect of this peptide. Calcitonin gene-related peptide which co-exists with substance P in sensory neurons of the airways, increased the ciliary frequency in 1 out of 6 experiments. In conclusion, our results indicate that ciliary activity can be directly modified via beta 2-adrenoreceptors. Other putative neuronal mediators did not reveal clearcut direct activity.