Figure 1. Age-related alterations in Sirt1 and AMPK expression. Western blot expression analysis of (A) Sirt1, (B) acetylated Ku70, (C) total AMPK and (D) phosphorylated AMPK (Thr172) performed with human cardiac tissue lysates from young and old men (m) or women (w). pAMPK was normalized to AMPK. Proteins were normalized to actin. Data are shown as the mean ± SEM (n= 6-8/group). Representative imaging of western blot analysis; the lanes were run on the same gel. All data were normalized to the corresponding control and expressed in relative units (r.u.).