(a, b, and c) Mitochondrial respiration measurements of proton leak, State 3 respiration, and electron transfer system of isolated mitochondria from 3 month-old Nrmt1−/− and wild type males. (d) Aconitase activity of liver from 3 month-old Nrmt1−/− and wild type males indicating less reactive oxygen species generation. Each bar represents the mean ± SEM of three mice. Statistical analysis was by Student's t-test, * denotes p<0.05.