Fig. 2.

Bz-423 decreases the mitochondrial Ca²⁺ retention capacity. Isolated WT (A and B) or Ppif^−/− mouse liver mitochondria (C) were incubated in the presence of 1 (open symbols) or 5 mM (closed symbols) Pi⋅Tris and Bz-423 as indicated. In B only, 1.6 μM CsA was added. Extramitochondrial Ca²⁺ was monitored, and CRC was determined by stepwise addition of 10 µM Ca²⁺ pulses. The measured CRC (i.e., the amount of Ca²⁺ accumulated before onset of Ca²⁺-induced Ca²⁺ release) was normalized to that obtained in absence of Bz-423 (CRC₀), and data are average of triplicate experiments ± SE. Absolute CRC values (nmol Ca²⁺/mg protein) at 1 mM Pi were 120 ± 0, 160 ± 20, and 166.7 ± 30.6 for A, B, and C, respectively; absolute CRC values (nmol Ca²⁺/mg protein) at 5 mM Pi were 86.7 ± 11.5, 126.7 ± 30.6, and 160 ± 20 for A, B, and C, respectively (n = 3 ± SD).