Figure 3

Effect of ETH129 on mitochondrial swelling and mitochondrial Ca²⁺ in isolated cardiomyocytes. (a) Swelling was assessed in isolated rat cardiac mitochondria by measuring the change in absorbance of the mitochondrial suspension at 540 nm. Mitochondria were energised with pyruvate/malate (5/5 mM) in the presence of 10 µM ruthenium red and 200 µM Ca²⁺. Then 20 µM ETH129 were added (arrow). Line a: Ca²⁺ + ETH129; line b: Ca²⁺  + ETH129 + CsA 2 µM; line c: Ca²⁺ alone; line d: ETH129 alone. (b) Isolated adult cardiomyocytes were loaded with 5 µM rhod-2 for 40 min at 37 °C and then incubated in a Tyrode’s buffer. After 5 min incubation (arrow) ETH129 was added to the medium. Fluorescence values 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 3–5 experiments. *p < 0.05 versus control (Ctrl). The ordinates of the bar graphs are the values of rhod-2 fluorescence observed at 30 min.