Kinetics of tert-butyl hydroperoxide decomposition in erythrocyte suspension

The kinetics of tert-butyl hydroperoxide (t-BHP) decomposition was examined in erythrocyte suspension from C57B1/6 mice by the chemiluminescence method. The reaction with horseradish peroxidase, t-BHP (20 nmol/ml), and luminol was accompanied by a rapid chemiluminescence increase. The integral value of the chemiluminescence signal correlated with the t-BHP concentration at every moment of time. In the erythrocyte suspension, the half-life of t-BHP decomposition was 23.8 s. The decomposition rate significantly decreased after pretreatment of the erythrocytes with o-phenanthroline (0.1 mM), EDTA (1 mM), benzohydroxamic acid (0.1 mM) or adriamycin (30 microM). These effects were not associated with the changes in the glutathione peroxidase activity and, more likely, could be related to the modification of the membrane iron-binding sites. The influence of iron chelators on the kinetics of t-BHP decomposition suggests the existence of various Fe-binding sites, that can decompose organic hydroperoxides upon their interaction with cell plasma membranes.