摘要：The effect of KB-R7943, an inhibitor of the plasmalemmal Na –Ca 2 exchanger, on mitochondrial Ca 2 transporters was examined with membrane-permeabilized cardiomyocyte-derived H9c2 cells expressing the fluorescent Ca 2 indicator, yellow cameleon 3.1, in the mitochondria. KB-R7943, as well as ruthenium red, inhibited the rise in mitochondrial Ca 2 on increasing the extramitochondrial Ca 2 concentration from 0 nM to 300 nM. CGP-37157, but not KB-R7943, inhibited the decline in mitochondrial Ca 2 on return to Ca 2 free extramitochondrial solution. These results indicated that KB-R7943 has inhibitory effects on the mitochondrial Ca 2 uniporter, but not on the mitochondrial Na –Ca 2 exchanger.
