1. Inhibition of calcium ionophore (A23187)-stimulated histamine release from rat peritoneal mast cells by azelastine: implications for its mode of action.
- Author
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Chand N, Pillar J, Diamantis W, Perhach JL Jr, and Sofia RD
- Subjects
- Animals, Ascitic Fluid immunology, Calcium pharmacology, Diphenhydramine pharmacology, Ketotifen pharmacology, Male, Mast Cells immunology, Rats, Rats, Inbred Strains, Calcimycin pharmacology, Histamine H1 Antagonists pharmacology, Histamine Release drug effects, Mast Cells drug effects, Phthalazines pharmacology, Pyridazines pharmacology
- Abstract
Azelastine is a novel, orally effective, long-acting, antiallergic agent. The ability of azelastine to influence calcium ionophore A23187-induced histamine release from rat peritoneal mast cells was investigated and compared with selected antiallergic drugs. The concentrations of drugs required to inhibit A23187 (0.2 microM)-stimulated histamine release by 50% (IC50S, microM) were as follows: azelastine 5; diphenhydramine 52; and ketotifen 200. Theophylline and sodium cromoglycate in a concentration range of 0.1-1000 microM failed to exert any significant inhibition of histamine release. The inhibitory effects of azelastine on A23187-stimulated histamine release were antagonized by high concentrations of exogenous Ca2+ ions. These data suggest that azelastine inhibits A23187-stimulated histamine release by interfering with the influx of Ca2+ into the mast cells.
- Published
- 1983
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