Leukotrienes C 4 and D 4 Increase the Ciliary Beat Frequency in Human Upper Airway Mucosa in Vitro

Abstract

It has been suggested that leukotrienes C₄ (LTC₄) and D₄ (LTD₄) released from upper respiratory mucosa influence mucociliary transport during allergic reactions. We studied the in vitro effects of leukotrienes C₄ and D₄ on the ciliary beat frequency (CBF) of human adenoid explants over a 5-hour period. Tissue explants were cultured at 35° C in Minimum Essential Medium Eagle (MEM). The CBF was measured using phase contrast microscopy and microphotometry. Measurements of CBF were 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% ± 2.69% and 29.84% ± 4.06%, respectively. To determine the specificity of the LTC₄ and LTD₄ effects, the ciliated epithelium was treated with the specific leukotriene receptor antagonist LY-171,883 before administration of LTC₄ and LTD₄. LY-171,883 (10⁻⁶ M) significantly inhibited the ciliostimulatory effects of both leukotrienes. Our findings indicate that LTC₄ and LTD₄ increase CBF in vitro by activation of the LTD₄ receptor.