Increased mitochondrial mass in mitochondrial myopathy mice - PubMed (original) (raw)

Biochemical measurements of the respiratory chain function in skeletal muscle. The results from biochemical measurements in skeletal muscle from myopathy (M, black bars) and control (C, white bars) mice at 1 month (1m), 2 months (2m), and 4 months (4m) of age are shown. The bars indicate mean ± SEM, and the asterisks indicate statistical significance (*, P < 0.05; **, P < 0.01). (A) CS activity in mmol/min/kg of muscle. (B) Relative enzyme activities of respiratory chain enzyme complexes I and III (NADH cytochrome c reductase, NCR), complex I (NADH coenzyme Q reductase, NQR), complexes II and III (SCR), and complex IV (COX). The relative enzyme activities presented as 100% in the figure correspond to the following absolute ratios of enzyme activities per unit of CS activity at 1, 2, and 4 months of age, respectively: NCR, 1.10, 0.83, and 1.19; NQR, 0.27, 0.22, and 0.24; SCR, 0.68, 0.69, and 0.55; COX, 1.82, 1.97, and1.94. (C) Results from measurements of the MAPR per unit of CS activity. The relative MAPR/CS presented as 100% in the figure corresponds to the following absolute ratios of MAPR per unit of CS activity at 1, 2, and 4 months of age, respectively: glutamate + succinate (G + S), 0.30, 0.35, and 0.33; TMPD + ascorbate (T + A), 0.26, 0.29, and 0.29; palmitoyl-

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-carnitine + malate (PC + M), 0.07, 0.07, and 0.06; succinate + rotenone (S + R), 0.06, 0.06, and 0.06. (D) Results from measurements of MAPR per kg of muscle. The relative MAPR per kg presented as 100% in the figure corresponds to the following absolute ratios of MAPR per kg of skeletal muscle (mmol ATP/min/kg muscle) at 1, 2, and 4 months of age, respectively: G + S, 15.4, 15.5, and 15.6; T + A, 13.6, 13.0, and 13.6; PC + M, 3.72, 3.12, and 2.95; S + R, 3.22, 2.60, and 2.88.