Fig. 5

Effects of 10 μM compound C (CC) treatment of ischemic-reperfused rat hearts on sensitivity of MPTP to Ca²⁺ in subsequently isolated mitochondria. Mitochondria from hearts subjected to ischemia–reperfusion in the absence (A) or presence (B) of CC added to the perfusion medium during the first 5 min of reperfusion were prepared as described in “Materials and methods”. MPTP opening was initiated by addition of CaCl₂ (100–500 μM) and was followed by monitoring of the classic decrease of absorbance at 540 nm at 25 °C as described in “Materials and methods”. Where indicated, 1 μM CsA was present from the start of the incubation period. Values are mean ± SEM (n = 8). Decrease of absorbance is expressed as a percentage of the respective initial value. ^a p < 0.05 versus 100, 150, 200 μM Ca²⁺ and versus 1 μM CsA + 500 μM Ca²⁺