Figure 5. SS-31 reverses the increased speed of mitochondrial permeability transition pore (mPTP) opening in aged mouse cardiomyocytes.
(A) A typical image shows 1 Hz line-scanning photo-excitation induced mPTP opening in a cardiomyocyte loaded with the mitochondrial membrane potential (Δψm) dye Tetramethylrhodamine methyl ester (TMRM). The sudden decline of TMRM fluorescence with time (rightward) indicates mPTP opening and Δψm loss. (B) 1 hr SS-31 and Bongkrekic Acid (BKA), but not carboxyatractyloside (CAT) treatments protect the photo-excitation induced mPTP opening. Quantification of time to mPTP opening from 418 to 658 mitochondria from 19 to 32 cells isolated from 3 to 4 mice in each group. One-way ANOVA with Dunnett’s test was applied. **p<0.01 vs young, ##p<0.01 vs old.