Table 3.
Age-associated changes in mitochondrial Grx1 and Grx2 activities.
|
SSM |
||||
|---|---|---|---|---|
|
Predicted activity |
Observed activity |
|||
| 6-mo | 24-mo | 6-mo | 24-mo | |
| Grx1 | 0.1 | 0.05 | 0.10±0.003 | 0.062±0.004 |
| Grx2 | 0.23 | 0.34 | 0.13±0.002 | 0.16±0.004 |
|
IFM |
||||
|---|---|---|---|---|
| Predicted activity | Observed activity | |||
| 6-mo | 24-mo | 6-mo | 24-mo | |
| Grx1 | 0.115 | 0.042 | 0.10±0.004 | 0.065±0.014 |
| Grx2 | 0.21 | 0.55 | 0.15±0.005 | 0.17±0.025 |
The deglutathionylation activities (predicted according to specific protein content, and observed) of Grx1 and Grx2 in the (A) SSM and (B) IFM from young adult and elderly F344 rat hearts represent the mean±SEM for at least duplicate assays of at least three separate biological samples (n>3), expressed as nmol/min/mg of mitochondrial protein. The predicted activities of Grx1 and Grx2 were calculated based on the protein content of these enzymes in each mitochondrial population, see Fig. 1, and using the specific activity of each enzyme [31,32].