Heart mitochondria isolated from cypD deficient mice are resistant to Ca2+-mediated swelling but not to Bnip3. A. Mitochondrial swelling of cypD deficient mitochondria treated with 0, 0.1, 0.5, or 1 μg Bnip3. B. Cytochrome c release in cypD deficient mitochondria by Bnip3._C. Mitochondria lacking cypD were incubated with 250 μM Ca2+ or 1 μg Bnip3 and swelling was assessed by measuring a decrease in absorbance. D. Western blot analysis of cypD deficient mitochondria for release of cytochrome c. E. Swelling of cypD deficient mitochondria was determined by measuring a decrease in absorbance. F. CypD deficient mitochondria were incubated with Bnip3 (1 μg), Bnip3ΔTM (1 μg), or tBid (100 ng) and analyzed for release of cytochrome c by Western blotting. Data shown are representative of three independent experiments.