Figure 2.

Effect of A23187 and ionomycin on mitochondrial calcein and TMRM fluorescence in isolated cardiomyocytes. Isolated adult cardiomyocytes were co-loaded with calcein, CoCl₂ and TMRM at 37 °C and then incubated in a Tyrode’s buffer. After 5 min incubation A23187 (a and b) or ionomycin (e and f) were added to the medium. (c) Cardiomyocytes isolated from wild type (WT) or CypD knock out (KO) mice were stained with 1 µM calcein in the presence of 1 mM CoCl₂, pre-treated with 2 µM CsA and 0.5 µM A23187 was added 5 min after recording. (d) Cardiomyocytes were incubated in a Tyrode’s buffer without Ca²⁺ (▪), supplemented with 100 µM EGTA (⚪, ▴) or containing 1.3 mM Ca²⁺ (◽). At 5 min, 0.5 µM A23187 was added (except⚪). Fluorescence values of calcein and TMRM were obtained by averaging pixel intensities after background substraction and were normalised as a percentage of the initial value. Each trace represents the mean ± SEM of 3 experiments.