Sho-seiryu-to, a traditional Japanese herbal medicine, has been used extensively in the treatment of allergic rhinitis. The effects of Sho-seiryu-to on electrical responses induced by acetylcholine in dissociated nasal gland acinar cells were investigated using patch-clamp and microfluorimetric imaging techniques. The application of Sho-seiryu-to inhibited both K+ and Cl- currents augmented by acetylcholine. The elevation of intracellular Ca2+ and Na+ concentrations induced by acetylcholine was also inhibited by Sho-seriyu-to. These findings suggest that Sho-seiryu-to attenuated the secretion of water and electrolytes from the nasal glands through an anti-cholinergic effect.