Table 3 Enzyme activity and hydrogen peroxide levels in aging skeletal muscle

6 ( n = 16)

12 ( n = 18)

18 ( n = 12)

24 ( n = 12)

SOD1 (U/mg protein)

19.4 ± 1.3

9.1 ± 0.3^acd

30.8 ± 2.5^abd

25.9 ± 1.3

SOD2 (U/mg protein)

5.7 ± 0.5

5.7 ± 0.4

4.7 ± 0.3

3.4 ± 0.1^ab

GPx (U/mg protein)

1.0 ± 0.2

1.1 ± 0.1^a

0.7 ± 0.1^abd

0.9 ± 0.2

Catalase (U/mg protein)

9.3 ± 0.9

12.1 ± 1.2^a

8.8 ± 1.2^bd

10.2 ± 0.9

Hydrogen Peroxide (μM)

1.12 ± 0.07

1.16 ± 0.04

2.42 ± 0.05^abd

1.74 ± 0.06

Superoxide (AFU)

8.1 ± 1.3

8.0 ± 0.3

8.9 ± 1.1

10.0 ± 0.6^ab