Figure 5

Arginase activity and expression in the brain of young and old WT and ApoE−/− mice. A) The highest level of arginase activity was found in old ApoE−/− mice. Each column represents mean ± SEM (n = 10 per group). * P <0.05 young WT vs old WT, young ApoE−/− vs old ApoE−/−, old ApoE−/− vs young WT, and old ApoE−/−vs old WT. B) Representative Western blots of ArgI (100 and 70 kDa bands) and quantification. Both bands of ArgI protein were significantly increased with aging in WT and ApoE−/− mice. In addition, the ArgI 100 kDa band was significantly up-regulated in ApoE−/− mice as compared to both age-matched WT. Each column represents mean ± SEM (n = 6 per group). * P <0.05 young WT vs old WT, young ApoE−/− vs old ApoE−/−, young WT vs young ApoE−/−, old ApoE−/− vs young WT, and old ApoE−/− vs old WT. C) Representative Western blots of ArgII (70 kDa band) and quantification. No significant changes in ArgII level were observed between WT and ApoE−/− mice (n = 6 per group).