POLYMORPHONUCLEAR LEUKOCYTE-GENERATED OXYGEN METABOLITES DECREASE BEAT FREQUENCY OF HUMAN RESPIRATORY CILIA

We investigated the effect of polymorphonuclear leukocyte (PMN)-genera ted oxygen metabolites on the ciliary beat frequency. PMNs were incuba ted with human respiratory cilia obtained by nasal brushing. The oxida tive metabolism was stimulated by opsonized zymosan, and ciliary beat frequency was evaluated before and after activation of PMNs. Ciliary b eat frequency was studied using video microscopy. Our results demonstr ate a significant decrease in ciliary beat frequency after activation of PMNs. This effect was reduced by catalase. These data suggest that the PMN-generated oxygen metabolites, particularly H2O2, decrease beat frequency of human respiratory cilia.