Effect of Divalent Cations and Metabolic Energy on the Anaphylactic Histamine Release from Rat Peritoneal Mast Cells

Abstract

Histamine release induced by the antigen from mast cells obtained from actively sensitized rats was enhanced by the same concentration of calcium in the medium, irrespective of whether the mast cells were isolated from contaminating cells or not. The time course of the release from isolated mast cells in the presence or absence of calcium was similar at 21 and 37 °C, respectively. The enhancing effect of calcium on the release was gradually lost when the cells were exposed to antigen prior to the addition of calcium. At equivalent concentrations, no other divalent cation tested could substitute for calcium. Similar concentrations of antimycin A prevented histamine release induced by antigen or compound 48/80. In the presence of the inhibitor, energy derived from glycolysis completely restored the release when induced by compound 48/80, whereas only partial restoration could be obtained in anaphylaxis. The latter effect was inhibited with iodoacetate in concentrations which were without effect in the absence of antimycin A. The results agree well with the view that antigen causes a passing state of increased permeability of the plasma membrane of the mast cells whereby calcium and eventually sodium might enter. Provided metabolic ATP is available, intracellular reactions are hereby initiated which lead to the release of histamine from its binding sites within the granular matrix.