Table 3.
Maximal activities of cytochrome c oxidase and citrate synthase measured in whole muscle homogenate (tissue) and in the isolated mitochondria
| Subjects | Tissue,
μmol·min−1·g−1
protein
|
Mitochondria,
μmol·min−1·mg−1 protein
|
||
|---|---|---|---|---|
| Cytochrome c oxidase | Citrate synthase | Cytochrome c oxidase | Citrate synthase | |
| Young | ||||
| Male (n = 6) | 146 ± 18 | 217 ± 21 | 1.21 ± 0.10 | 0.46 ± 0.05 |
| Female (n = 6) | 107 ± 8 | 211 ± 16 | 1.06 ± 0.14 | 0.44 ± 0.06 |
| Middle-aged | ||||
| Male (n = 7) | 106 ± 10 | 181 ± 20 | 1.08 ± 0.16 | 0.40 ± 0.08 |
| Female (n = 7) | 104 ± 8 | 158 ± 11 | 0.79 ± 0.09 | 0.35 ± 0.05 |
| Old | ||||
| Male (n = 7) | 101 ± 12 | 178 ± 22 | 1.09 ± 0.17 | 0.36 ± 0.02 |
| Female (n = 9) | 80 ± 3 | 153 ± 6 | 0.58 ± 0.04 | 0.27 ± 0.02 |
| Age effect P | 0.0044 | 0.0109 | 0.0657 | 0.0346 |
| Gender effect P | 0.0176 | 0.1911 | 0.0032 | 0.1994 |
Values are expressed per protein content measured in the same samples. Individual numbers are the mean of two muscle biopsies taken from different legs.