CETIRIZINE EXERTS ANTIINFLAMMATORY EFFECTS ON HUMAN NEUTROPHILS

Leukotrienes are potent lipid mediators involved in acute and chronic inflammatory processes and allergic inflammation. Cetirizine is an H-1 -receptor antagonist used in the treatment of allergic symptoms. We an alyzed the effect of cetirizine on the formation of leukotriene B-4 (L TB(4)) after stimulation of human peripheral blood neutrophils. The in flammatory mediators were analyzed after cellular activation with diff erent stimuli: the Ca ionophore A23187, which bypasses membranous sign al transduction elements; the bacterial peptide formyl-methionine-leuc yl-phenylalonine (fMLP), which activates cells by binding to a GTP-pro tein (G-protein)-coupled receptor, and with sodium fluoride (NaF), whi ch directly activates G-proteins. After cellular preincubation with ce tirizine, the amounts of LTB(4) generated from neutrophil granulocytes decreased significantly when the cells were subsequently stimulated w ith either fMLP or NaF, in contrast to stimulations with the Ca ionoph ore. The data provide evidence that cetirizine exerts anti-inflammator y effects apart from H-1 antagonism.