Local anesthetics and tracheal ring ciliary activity

The effects of local anesthetics on ciliary activity were studied using ferret tracheal rings maintained in vitro. Ciliary activity was quantitated visually after exposure to varying concentrations of mepivacaine, lidocaine, procaine, chloroprocaine, and bupivacaine. The recovery of ciliary activity was determined after tracheal rings were washed free of the local anesthetic agent. Mepivacaine was the least toxic, with no effect on ciliary activity at a 1.0% concentration. Bupivacaine was the most toxic, with irreversible damage to respiratory epithelium at a concentration of 0.13%. Lower concentrations caused ciliostasis, with some recovery after removal of the anesthetic. Licocaine, procaine, and chloroprocaine also depressed ciliary activity which, in general, was reversible after removal of the anesthetic.