Figure 5.

BAC promoted opening of the mPTP, as inferred from recording of the (a) membrane potential and (b) swelling of rat liver mitochondria isolated in EGTA-free medium. The basal incubation medium was supplemented with 20 mM Tris-succinate+rotenone (2 μg/mg protein), mitochondria (0.5 mg protein/ml), and either (a) 20 mM safranin or (b) 40 mM KCl. (a, b) Curves 1, spontaneous depolarization (a, curve 1) and swelling (b, curve 1) of rat liver mitochondria; (a, b) curves 2, the media initially contained 0.5 mM EGTA; in (a), curve 1, depolarizing effect of 8 μM BAC and repolarization after the subsequent addition of 0.5 mM EGTA; in (b), curve 3, promotion of mitochondrial swelling by 8 μM BAC and subsequent compression of mitochondria after the addition of 0.5 mM EGTA at the end of incubation.