Effect of fudosteine, a new cysteine derivative, on mucociliary transport

We examined the effect of fudosteine ((—)‐(R)‐2‐amino‐3‐(3‐hydroxypropylthio)propionic acid) on the mucociliary transport (MCT) rate in quails. The MCT rate was estimated by ash transport velocity on the tracheal mucosa of quails. Fudosteine (500 mg kg−1, p.o.) did not affect the normal MCT rate. However, topical application of fudosteine to the tracheal mucosa dose‐dependently protected the impairment of the MCT rate caused by exposure to cigarette smoke. The results suggest that fudosteine may participate in the defence mechanism in the respiratory tract against irritant gases.