Figure 1. SIRT3 prevents mitochondrial permeability transition in cardiac tissue during aging. Mitochondrial swelling induced by Ca2+. Mitochondria from 3 (A), 6 (B) and 16 months old (C) wt and SIRT3−/− mouse hearts subjected to Ca2+-induced mitochondrial swelling, measured as % decrease in the initial optical density (OD540) in the presence or absence of 1 μM CsA (n=4 per group and age). All error bars show s.e.m.