title: In vitro inhibition of allergic histamine release by calcium antagonists.
abstract: The ability of calcium entry blockers to inhibit allergic histamine release from rabbit leukocytes was studied. Bepridil, verapamil, nifedipine, diltiazem and TMB-8 produced concentration-dependent inhibition of allergic histamine release from rabbit leukocytes. The calculated IC50s (microM) were as follows: verapamil = 1.3; bepridil = 2.3; TMB-8 = 3.0; nifedipine = 3.3; and diltiazem = 5.3. Verapamil also exerted concentration-dependent inhibition of allergic histamine release from human basophils with an IC50 of 3.7 microM. These agents may act by interfering with the influx of Ca2+ into the leukocytes as well as calcium-dependent steps (e.g., activation of calmodulin, phospholipase A2 and/or 5-lipoxygenase etc.) in the process of histamine secretion.
authors.forename: N
authors.initials: N
authors.lastname: Chand
authors.forename: J
authors.initials: J
authors.lastname: Pillar
authors.forename: W
authors.initials: W
authors.lastname: Diamantis
authors.forename: R D
authors.initials: RD
authors.lastname: Sofia
mesh_terms: D000818:Animals; D001491:Basophils / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D006636:Histamine Release / Q000187:drug effects*; D006967:Hypersensitivity / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D011817:Rabbits; D014700:Verapamil / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D014700:Verapamil