title: Comparison of the action of calcium antagonists on basophil histamine release.
abstract: The inhibitory capacity of calcium antagonists on basophil histamine release was examined in allergic patients and in controls. All dihydropyridines tested (nifedipine, nimodipine, nitrendipine, nicardipine, felodipine) dose-dependently inhibited anti-IgE- and A23187-induced release with an order of potency of felodipine greater than nicardipine greater than nifedipine = nimodipine = nitrendipine. Only the inhibition induced by felodipine and nicardipine on anti-IgE-induced release could be counteracted by increasing extracellular calcium. Diltiazem, not belonging to the dihydropyridines, was a weak inhibitor. A combination of felodipine and verapamil in low concentrations exerted a synergistic inhibitory effect on histamine release, whereas this was not the case with other combinations of antagonists. The results suggest differences in the mode of action of the 1.4-dihydropyridines. This might be of significance in the search for calcium antagonists suitable in the treatment of allergic diseases.
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D001491:Basophils / Q000187:drug effects* / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000473:pathology; D007073:Immunoglobulin E / Q000276:immunology; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D002121:Calcium Channel Blockers; D007473:Ion Channels; C026408:anti-IgE antibodies; D007073:Immunoglobulin E