THE EFFECT OF LEUKOTRIENE C4 ON MUCIN RELEASE INTO THE CAT TRACHEA in vivo AND in vitro

We have tested the effect of leukotriene C4 (LTC4, 6 X 10(-8) to 6 X 10(-5) M) on the output of radiolabelled mucins from the trachea of the anaesthetized cat. Doses between 6 X 10(-7) M and 6 X 10(-5) M stimulated mucin release. FPL 55712 (9.5 X 10(-6) M) partially antagonized the effect of the highest dose of LTC4. Tests of LTC4 (6 X 10(-8) to 6 X 10(-6) M) on cat trachea in vitro failed to show any effect on mucin secretion. We conclude that leukotrienes may be one of the mediators of mucus secretion into the inflamed airway.