FIG. 5.

Reversible calcium-induced mPT and inhibition of swelling by mPT inhibitors in human brain mitochondria. (A) Representative traces (n = 3) of reversible swelling in human brain mitochondria induced by 200 μM Ca²⁺, followed by 400 μM of the Ca²⁺ chelator EGTA. Swelling was induced a second time by Ca²⁺ (1 mM), and mitochondria were then permeabilized by the non-specific ionophore alamethicin. (B) Representative traces (n = 2) of Ca²⁺-induced swelling with or without the presence of the endogenous mPT inhibitor ADP (100 μM), and the cyclophilin D (CypD) inhibitor cyclosporin A (CsA; 1 μM). Mitochondria were challenged with two additions of 100 μM Ca²⁺, followed by exposure to alamethicin. (C) Electron micrographs of brain mitochondria following isolation, calcium infusion, and alamethicin exposure [scale bars = 1 μm; ADP, adenosine diphosphate; mPT, mitochondrial permeability transition; EGTA, ethyleneglycol-bis-(β-aminoethylether)-N,N,N′,N′-tetraacetic acid; a.u., arbitrary units]. Color image is available online at www.liebertpub.com/neu.