Figure 7.

Decreased brain protein oxidation in aged EC-SOD transgenic mice. A, Spectrophotometric assays for protein carbonyls in brain homogenates. Levels of protein oxidation (protein carbonyls) were determined as described in Materials and Methods. Results were expressed as percentage of young wild-type (young WT) values. Error bars indicate SEM for five determinations. In this assay, young EC-SOD transgenic mice (young TG) exhibited similar protein carbonyl levels compared with young WT mice, whereas old EC-SOD transgenic mice (aged TG) exhibited significantly lower protein carbonyl levels than old wild-type mice (aged WT); **p < 0.05 by Student's t test. B, Western blot analysis for protein carbonyls in hippocampal CA1 homogenates. The hippocampal CA1 region of young (3 months) or old (>20 months) wild-type or EC-SOD transgenic mice was dissected and homogenized, and the lysates were centrifuged to remove insoluble material. Total protein (50 μg) was loaded in each lane. The experiment was performed four times; a representative blot is shown.