Abstract
A comparative study was carried out on the histamine release from rat neutrophils and mast cells by calcium ionophore A 23 187 (Ionophore). A maximum release of histamine from neutrophils was induced by 10-6 g/ml Ionophore and that from mast cells was 5×10-6 g/ml. A fairly good correlation was found between the 45Ca incorporation into and the histamine release from both cells . The Ionophore-induced histamine release from both cells was decreased in Ca2+-free Tyrode's solution and by pretreatment with 0.05 M EDTA. Effects of different drugs on Ionophore-induced histamine release from neutrophils were similar to those seen in mast cells. Dibutyl cyclic adenosine monophosphate, theophylline, isoproterenol and prostaglandin E1 had no or only a slight inhibition on the release. The dose dependent inhibition of release was observed with disodium cromoglycate, N-(3', 4'-dimethoxycinnamoyl) anthranilic acid and disodium baicalein phosphate, in experiments using both cells. Colchicine did not inhibit the reaction in these cells, however phosphatidylserine enhanced the reaction. On the other hand, the effect of concanavalin A was different in each type of cells, the release from mast cells was inhibited while the release from neutrophils was potentiated. These findings suggest the similarity of biochemical events in Ionophore-induced histamine release from neutrophils and mast cells.
