Mouse liver mitochondria were prepared as described and resuspended in MRM buffer (250 mM sucrose, 10 mM HEPES, pH 7.5, 1 mM ATP, 5 mM sodium succinate, 80 mM ADP, 2 mM K2HPO4) at a concentration of 0.5 mg ml 21 (ref. 18). Rat liver mitochondria were isolated from 4–6-month-old Fischer 344 £ brown Norway F1 rats by differential centrifugation as described, except the final wash and resuspension...