Calcium uniporter regulates permeability transition pore in brain mitochondria

Objective To determine whether the mitochondrial calcium uniporter plays a role on the mitochondrial permeability transition pore in isolated rat brain mitochondria.Methods Mitochondrial permeability transition pore opening was determined by mitochondrial swelling.Isolated mitochondria were treated with mitochondrial calcium uniporter inhibitor ruthenium red,activator spermine,and mitochondrial permeability transition pore inhibitor cyclosporin A,separately.The continuous change in absorbance was observed.Results Treatment with ruthenium red(5μmol/L),the extent and rate of decline in the absorbance were attenuated.Spermine(100μmol/L) greatly enhanced the extent and rate of decline,while cyclosporin A(2μmol/L) reversed the effect.Conclusion These results indicate that the mitochondrial calcium uniporter plays a role on the mitochondrial permeability transition pore in isolated rat brain cortex mitochondria.