Figure 6 –
Maximum rate of sites generating superoxide/hydrogen peroxide in isolated skeletal muscle mitochondria from wildtype and tazkd mice at 3, 8 and 12 months of age. The rate of superoxide/hydrogen peroxide generated by sites associated with the NADH/NAD+ (A-E) and QH2/Q (G-H) isopotential pools. In the NADH/NAD+ isopotential pool, the rate of superoxide/H2O2 production was measured from the flavin (F) binding sites of: (A) complex I (site IF), (B) 2-oxoadipate dehydrogenase (site AF), (C) branched chain 2-oxoacid dehydrogenase (site BF), (D) pyruvate dehydrogenase (site PF), and (E) 2-oxoglutarate dehydrogenase (site OF). Complex I produces superoxide/H2O2 from two sites: (A) site IF and (F) site IQ (ubiquinone (Q) binding site). In sites associated with the QH2/Q isopotential pool, the rate of superoxide/hydrogen peroxide production was measured from (G) site EF, in the electron transfer flavoprotein (ETF) and ETF:ubiquinone oxidoreductase (ETF:QOR) system, (H) site DQ, in dihydroorotate dehydrogenase, (I) site GQ (glycerol 3-phosphate dehydrogenase), (J) site IIF, in complex II, and (K) site IIIQo, in complex III. Values are mean ± SEM, n≧3 independent mitochondrial preparations and were normalized by mitochondrial protein (ptn). *,p<0.001 2-way ANOVA.