Oxidation of NAD(P)H and succinate in leaf mitochondria purified from control and antimycin A-sprayed potato plants. Data are presented as percentage of control in each experiment (A) and as absolute values in nmol NAD(P)H or succinate min-1 mg-1 (B). Internal NADH oxidation was measured on osmotically burst mitochondria in the absence (Total) and presence (+ Rot.) of the complex I inhibitor rotenone. External NAD(P)H oxidation was measured in the presence of Ca2+. A3, A10 and A30 denote mitochondria isolated from leaves sprayed with 3, 10 and 30 μM antimycin A, respectively. Control leaves (C) were sprayed with solvent only. Error bars indicate standard error for 3 independent experiments, except for succinate oxidation (standard deviation, n = 2).