Effect of atropine on ciliary beat in human upper respiratory tract epithelial cells

The mucociliary apparatus is a fundamental element among the defensive mech anisms of the airways. In man, average ciliary beat frequency (CBF) has bee n reported to be between 600 and 1,000 beats/min and does not vary signific antly at different sites along the respiratory tract. Ciliary function is a ltered by numerous factors, including temperature, pH, cigarette smoke, dru gs, and alcohol. The aim of the present study was to evaluate whether intra venous (i.v.) infusion of atropine alters CBF. We studied nine patients (si x females and three males, mean age 42.9 years) with otosclerosis, a nonres piratory disease. All patients were scheduled for surgical stapedectomy. In all patients, nasal brushing was performed before and 20 min following i.v . injection of 0.5 mg atropine sulphate. The cellular samples, maintained v iable in tissue medium, were observed under a microscope and filmed. A quan titative evaluation of ciliary activity was obtained by playing the film ba ck in slow motion. The mean CBF value prior to atropine infusion in the nin e patients studied was 588.12 (+/-53.29 SD) beats/min. After infusion of at ropine, mean CBF was 442.33 (+/-52.82 SD) beats/min. The mean percentage dr op in CBF following atropine infusion was 24.79% (t=5.82, p<0.001). Our dat a show a drop in in vitro CBF following atropine infusion which, presumably reflects a fall in the in vivo efficacy of mucociliary transport. Atropine treatment determined a loss in CBF that was inversely correlated with incr easing age.