EFFECT OF LEUKOTRIENE D-4 ON TRACHEAL MUCOCILIARY TRANSPORT VELOCITY IN QUAILS

We investigated the effect of leukotriene D-4 (LTD(4)) on tracheal muc ociliary transport in quails. Topical application of LTD(4) (0.2-2 ng) to tracheal mucosa dose-dependently increased mucociliary transport v elocity (MCTV) in 5 or 10 min after application. Forty minutes after a pplication of 2 ng of LTD(4), MCTV was decreased to about 84% of that in the control group. Both the transient increase and the subsequent d ecrease induced by 2 ng of LTD(4) were blocked by ONO-1078 (Pranlukast : -phenylbutoxy)-benzoylamino]-2-(tetrazol-5-yl)-4H- 1-benzopyran) (0. 03-3 mg/kg, i.m.), a specific leukotriene antagonist. These results su ggest that LTD(4) possesses a biphasic effect on tracheal mucociliary transport through leukotriene receptors.