KINETICS OF OXYGEN-METABOLISM INDEXES IN THE COURSE OF HISTAMINE-SECRETION FROM RAT MAST-CELLS

In this study data are presented on the kinetics of changes in malondialdehyde content (MDA), lipoxygenase activity (LO), superoxide dismutase activity (SOD), glutathione peroxidase activity (GSH-Px) and glutathione reductase activity (GSSG-Red) during the course of histamine secretion from rat mast cells. Both receptor-mediated (antigen, polymyxin B, compound 48/80) and non-receptor (the calcium ionophore A 23187) stimuli of mast cell activation were investigated. A similar alteration in all the studied indices was observed after challenge with receptor-mediated stimuli. The earliest event was a decrease in SOD-activity, which coincided with the increase in histamine secretion. SOD-activity then gradually increased above the baseline levels. Similar changes in GSSG-Red- and GSH-Px-activities were also observed. The increase in MDA content occurred slightly later. Challenge with the calcium ionophore A 23187 did not cause a reduction in SOD-activity, only the increase in activity was observed. Histamine release induced by all stimuli was accompanied by a marked elevation in enzymatic peroxidation (LO-activity). Diethyldithiocarbamate (DTC), which inhibits SOD, not only blocked the enzyme activity but also caused a dose-dependent inhibition of histamine release and an inhibition of the elevation of enzymatic peroxidation in mast cells challenged with compound 48/80. © 1990 Birkhäuser Verlag.