Calcium uptake in mast cells, energy metabolism and histamine secretion

Abstract

The inhibition of energy metabolism of mast cells causes an inhibition of histamine secretion. As the secretion is generally initiated by the influx of calcium into the cell, we have made correlative studies of the effect of blocking the energy metabolism on calcium uptake and histamine secretion. When the influx of calcium is increased by exposing the cells to low concentrations of saponin or ionophore A23187, histamine release occurs, having the character of a secretory response. Brief incubation of the cells with antimycin A, 10(-9) M-10(-7) M, prior to exposure to saponin or the calcium ionophore gave similar dose-response curves for the inhibitory effect of antimycin A on calcium uptake and histamine release. The inhibition of calcium uptake in untreated mast cells by antimycin A, 10(-9) M-10(-7) M, showed good correlation to the inhibition of anaphylactic histamine release and the release induced by compound 48/80. The antigen-induced histamine release is dependent on extracellular calcium and an inhibition of its uptake by antimycin A could by itself inhibit the release. Compound 48/80 on the other hand induces histamine release both in the presence and absence of calcium, and both are similarly inhibited by 10(-9) M-10(-7) M antimycin A. This indicates that antimycin A has other sites of action apart from the inhibition of the influx of extracellular calcium. The inhibitory effect of antimycin A on compound 48/80-induced histamine secretion in the absence of extracellular calcium may be due to an inhibition of energy requiring steps in the final phase of the secretory process.(ABSTRACT TRUNCATED AT 250 WORDS)