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. 2020 Nov 19;595(3):415–432. doi: 10.1002/1873-3468.13973

Fig. 5.

Fig. 5

Maximum rate of superoxide/hydrogen peroxide production in isolated heart mitochondria from wild‐type 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) 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 IFand (F) site IQ(Q binding site). In sites associated with the QH2/Q isopotential pool, the rate of superoxide/hydrogen peroxide production was measured from (G) site GQ(glycerol 3‐phosphate dehydrogenase), (H) site DQ, in dihydroorotate dehydrogenase, (I) site EF, in the electron transfer flavoprotein (ETF) and ETF:ubiquinone oxidoreductase (ETF:QOR) system, (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). Two‐way ANOVA was used to determine significance. H2O2production rate from sites IQ and IIIQo is greater in 7‐month‐old compared to 3‐ and 12‐month‐old in wild‐type (2‐way ANOVA, age: P < 0.003, interaction P = 0.1727) but not in tazkd mice (2‐way ANOVA, age: P = 0.6422, interaction: P = 0.9998).*P< 0.05; **P< 0.01; ***P< 0.0001.