Fig. 7.
In vitro DLDH oxidative inactivation by mitochondria-generated ROS. Mitochondrial respiration buffer contained 110 mM mannitol, 10 mM KH2PO4, 60 mM Tris, 60 mM KCl, 0.5 mM EGTA, pH 7.4. Mitochondria (0.25 mg/ml) were incubated in the presence of Antimycin A (50μM) and the indicated respiratory substrates (pyruvate/malate: 5 mM/5 mM; succinate: 10 mM). Control contained neither Antimycin A nor substrates. DLDH dehydrogenase activity was measured spectrophotometrically as described in Figure legend 4. Values, expressed as percentage of control in each group, are mean ± SEM of three independent experiments. * p < 0.05 for comparison between the experimental groups and the control within each age group.