Table 4.

Mitochondrial respiratory chain enzyme activities in muscle

Age and genotype	I+III	II+III	COX	CS	I+III/CS	II+III/CS	COX/CS
1 mo
WT	4.25 ± 2.47	1.20 ± 0.89	2.00 ± 1.88	474.00 ± 318.48	8.50 ± 8.54	9.67 ± 0.58	20.40 ± 18.02
MUT	3.68 ± 2.76	0.76 ± 0.29	1.08 ± 1.20	576.00 ± 219.61	7.75 ± 8.54	11.25 ± 5.85	11.20 ± 8.52
4 mo
WT	12.86 ± 8.99	1.00 ± 0.14	2.55 ± 1.79	214.61 ± 80.16	22.50 ± 12.58	18.00 ± 8.00	40.00 ± 38.47
MUT	5.74 ± 2.50	0.82 ± 0.21	3.50 ± 1.45	271.60 ± 46.33	18.33 ± 7.53	20.00 ± 5.77	54.29 ± 19.88
6 mo
WT	8.80 ± 1.90	0.95 ± 0.48	5.10 ± 1.45	260.11 ± 77.47	36.67 ± 10.33	23.33 ± 5.16	85.00 ± 27.39
MUT	3.88 ± 1.79*	0.73 ± 0.17	6.58 ± 5.12	292.26 ± 64.59	13.75 ± 7.50*	15.00 ± 5.77*	82.50 ± 46.46

Values are expressed as mean ± sd nanomoles per minute per gram of tissue, normalized to milligrams of protein or to CS activity. I+III, complex I+III; II+III, complex II+III; COX, cytochrome c oxidase; CS, citrate synthase; WT, wild-type; MUT, mutant.

^*P ≤ 0.05.