title: A clinical study of concanavalin A-induced histamine release utilizing a single isotopic enzymatic assay of histamine.
abstract: Concanavalin A (Con A)-induced histamine release from cells of subjects with extrinsic asthma, intrinsic asthma or urticaria and normal individuals was examined utilizing a single isotopic enzymatic assay for histamine. Maximum histamine release by Con A occurred with 0.9 to 4.5 microgram/ml. The mean percentage of maximum histamine release by Con A from cells of donors with extrinsic asthma was 36(+/- 19.3)% while that from cells of normal individuals was 21.4(+/- 23.7)%. However, there was no significant difference between the two groups. The higher reactivity to Con A of cells from individuals with intrinsic asthma or urticaria was not observed compared to that of the normal group. The histamine release by Con A was not correlated with IgE level in the plasma (r = 0.35). It was observed that compound 48/80 inhibited the enzymatic reaction in the isotopic, enzymatic assay.
mesh_terms: D001249:Asthma / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology*; D006637:Histamine N-Methyltransferase; D006636:Histamine Release / Q000187:drug effects*; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis; D014581:Urticaria / Q000276:immunology
chemical_list: D003208:Concanavalin A; D007073:Immunoglobulin E; D006637:Histamine N-Methyltransferase