Table 1.
Measurement of antioxidants: SOD-1, SOD-2, catalase, and GPx from hippocampal tissues of EC-SOD transgenic mice and wild-type littermates
| 3 months old | >20 months old | |||
|---|---|---|---|---|
| Non-Tg (n) | EC-SOD Tg (n) | Non-Tg (n) | EC-SOD Tg (n) | |
| SOD-1 | 1.00 ± 0.11 (4) | 1.08 ± 0.08 (4) | 1.27 ± 0.14* (6) | 1.24 ± 0.08* (5) |
| SOD-2 | 1.00 ± 0.06 (4) | 1.04 ± 0.05 (6) | 1.19 ± 0.16 (4) | 1.18 ± 0.07 (5) |
| Catalase | 1.00 ± 0.07 (5) | 1.02 ± 0.06 (5) | 1.25 ± 0.04** (5) | 1.27 ± 0.07** (5) |
| GPx | 11.3 ± 0.73 (4) | 11.6 ± 0.67 (4) | 16.6 ± 0.64** (7) | 15.8 ± 0.72** (7) |
Hippocampal homogenates prepared from wild-type and EC-SOD transgenic (Tg) mice were examined by Western blot analysis with antibodies for SOD-1, SOD-2, and catalase. In addition, enzymatic activity of GPx was measured. Results of SOD-1, SOD-2, and catalase are presented as arbitrary units determined by densitometry and normalized to 3-month-old wild-type controls. GPx activity was measured as the rate of NADPH consumption (in nanomoles) per minute per milligram of protein. The number of determinations for each measurement is indicated in parentheses. Data are presented as mean ± SEM. Two-way ANOVA followed by Bonferroni's post hoc tests showed that there is no interaction between age and genotype, and no effect of genotype was observed. However, there was an effect of age for SOD-1 and catalase levels and GPx activity (*p < 0.05 and **p < 0.005, respectively). There also was a nonstatistically significant trend for an age effect for SOD-2 (p = 0.077). Thus, antioxidant activity was not altered in EC-SOD transgenic mice, but overall antioxidant levels increase with age in both wild-type and EC-SOD transgenic mice.