Reverse electron flow from CII to CI stimulates production of ROS when mitochondria are incubated with succinate without rotenone in the LEAK state at a high mt-membrane potential. Depolarisation of the mt-membrane potential (e.g. after ADP addition to stimulate OXPHOS) leads to inhibition of RET and therefore, decrease of RET-initiated ROS production. RET can be also measured when mitochondria are respiring using Gp without rotenone in the LEAK state. Addition of IQ-side inhibitors (ubiquinone-binding side of CI) of CI usually block RET. The following SUIT protocols allow you to measure RET-initiated H2O2 flux in mitochondrial preparations: SUIT-009 and SUIT-026.
MitoPedia topics: Enzyme