Effects of dibutyryl cyclic adenosine monophosphate and colforsin on mucociliary transport using frog palate

For the determination of mucociliary transport, a method was developed to assess the mucociliary transport force (MCTF). Using this method, effects of isoprenaline (isoproterenol), theophylline, dibutyryl cyclic adenosine monophosphate (AMP) and colforsin on mucociliary transport were investigated for 15 min after the drug application. These agents induced a significant, dose-related increase in MCTF. Propranolol, a beta-adrenergic antagonist, inhibited the effect of isoprenaline, and 9-(tetrahydro-2-furyl)adenine, an inhibitor of adenylate cyclase, inhibited the effect of colforsin. These results indicated that mucociliary transport was stimulated by the agents which increased intracellular cyclic AMP level, and that intracellular cyclic AMP played an important role in the maintenance and/or regulation of mucociliary transport.