Fig. 4.

NAD⁺-consuming enzymes were upregulated with aging. Representative Western blots (a) of the protein content of NAMPT (b), CD38 (c), PARP-1 (d), cleaved form of PARP-1 (e), and pADPr (f) in two skeletal muscles and cardiac muscle of young (N = 8), mid-aged (N = 8), and old mouse (N = 8), respectively. Data are mean ± SEM. ^*P < 0.05, ^**P < 0.01, Mid-aged or Old vs. Young; ^†P < 0.05, ^††P < 0.01, old vs. mid-aged