Fig. 7.

Full activation of mitochondrial Ca²⁺ uptake during RyR-mediated Ca²⁺ release. (A) Ca²⁺- and caffeine induced [Ca²⁺]_m and Δψ_m responses were measured in permeabilized myotubes using rhod-2 and TMRM, respectively. Uncoupler (1 µM CCCP and 2.5 µg/ml oligomycin) was added as indicated. (B) The rate of mitochondrial Ca²⁺ uptake was measured at varying [Ca²⁺] obtained by the addition of CaCl₂ in adherent rhod-2 loaded permeabilized cells. The added CaCl₂ concentration values are indicated with arrows below the x axis, and the effective [Ca²⁺]_c were calculated. To prevent Ca²⁺-induced Ca²⁺-release via RyR2, the cells were preincubated with thapsigargin to inhibit the SR Ca²⁺ ATPase and hence to deplete the SR prior to Ca²⁺ addition. Reproduced from Szalai et al. [191] with permission