Mechanisms of mitochondrial superoxide formation remain poorly understood despite
considerable medical interest in oxidative stress. Superoxide is produced from both
Complexes I and III of the electron transport chain, and once in its anionic form it is too
strongly charged to readily cross the inner mitochondrial membrane. Thus, superoxide
production exhibits a distinct membrane sidedness or" topology." In the present work, using
measurements of hydrogen peroxide (Amplex red) as well as superoxide (modified …