Effect of NEM, Cu(OP)2, and PhAsO on mitochondria and mitoplasts. 0.5 mg/ml Tspo+/+ liver mitochondria (trace a) or mitoplasts (trace b) (A) and TspoloxP (trace a) or AlbCre;TspoloxP (trace b) liver mitochondria (B) were suspended in assay buffer supplemented with 5 mm succinate plus 1 μm rotenone; where indicated, 150 μm Ca2+, 0.5 mm NEM, and 5 μm alamethicin were added. C–F, 0.5 mg/ml TspoloxP (C and E) or AlbCre;TspoloxP mouse liver mitochondria (D and F) in the same buffer as in A and B were supplemented with 15 μm Ca2+ and 5 μm Cu(OP)2 (C and D) or 15 μm PhAsO (E and F) (traces a). In traces b (C and D) 0.2 mm MBM+ was added prior to Cu(OP)2. E and F, medium was supplemented with 1 μm CsA. Representative traces of three independent experiments are shown.