LEUKOTRIENES C-4 AND D-4 INCREASE THE CILIARY BEAT FREQUENCY IN HUMANUPPER AIRWAY MUCOSA IN-VITRO

It has been suggested that leukotrienes C-4 (LTC4) and D-4 (LTD4) rele ased from upper respiratory mucosa influence mucociliary transport dur ing allergic reactions, We studied the in vitro effects of leukotriene s C-4 and D-4 on the ciliary beat frequency (CBF) of human adenoid exp lants over a 5-hour period, Tissue explants were cultured at 35 degree s C in Minimum Essential Medium Eagle (MEM). The CBF was measured usin g phase contrast microscopy and microphotometry. Measurements of CBF w ere recorded in medium alone and in medium containing LTC4 or LTD4 at concentrations of 10(-8) and 10(-6) M, LTC4 and LTD4 increased CBF at concentrations of 10(-8) and 10(-6) M with increases of 20.51% +/- 2.6 9% and 29.84% +/- 4.06%, respectively, To determine the specificity of the LTC4 and LTD4 effects, the ciliated epithelium was treated with t he specific leukotriene receptor antagonist LY-171,883 before administ ration of LTC4 and LTD4. LY-171,883 (10(-6) M) significantly inhibited the ciliostimulatory effects of both leukotrienes. Our findings indic ate that LTC4 and LTD4 increase CBF in vitro by activation of the LTD4 receptor.