Figure 1.

mPTP opening induced by Ca²⁺ in isolated mitochondria is blocked by CSA and Ruthenium Red. (a) Mitochondrial swelling induced by Ca²⁺ (detected as an increase in light transmittance) corresponds to mPTP opening (black) as this swelling is blocked by mPTP inhibitor, CSA (red) or by inhibition of the mitochondrial Ca²⁺ uptake with Ruthenium Red. Alamethicin was added at the end of the experiments to achieve maximal swelling. (b) Electron micrographs of condensed mitochondria before (control) and swollen mitoplasts after mPTP activation (mPTP). Scale bar is 100 nm.