title: Effect of ketotifen on human alveolar macrophages.
abstract: In order to examine the possibility of human alveolar macrophages being an effector site of an antiasthmatic drug, we studied the effect of ketotifen on chemiluminescence and Ca-activated K conductance at single channel level because they are associated with the activation of macrophages. Peak chemiluminescence response, induced by a single concentration of phorbol myristate acetate (0.5 micrograms/ml), was inhibited by 28 +/- 3, 51 +/- 8, and 76 +/- 7% by ketotifen concentrations of 0.02, 0.12, and 0.24 mmol/L, respectively. The inhibition of chemiluminescence by ketotifen concentrations of 0.12 and 0.24 mmol/L was also observed in macrophages stimulated with zymosan activated serum (54 +/- 7 and 80 +/- 6%, respectively). Moreover, ketotifen, 0.24 mmol/L, inhibited Ca-activated K channel currents by 44 +/- 7% (large currents) and 48 +/- 13% (small currents). These results may explain, at least partly, antiasthmatic effects of ketotifen.
mesh_terms: D000166:Acridines / Q000494:pharmacology; D006801:Humans; D007473:Ion Channels / Q000187:drug effects / Q000378:metabolism; D007665:Ketotifen / Q000494:pharmacology*; D008163:Luminescent Measurements; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
chemical_list: D000166:Acridines; D007473:Ion Channels; C033472:10,10'-dimethyl-9,9'-biacridinium; D015054:Zymosan; D013482:Superoxide Dismutase; D013755:Tetradecanoylphorbol Acetate; D007665:Ketotifen