Oxidative Stress-Related Mechanisms and Antioxidant Therapy in Diabetic Retinopathy

Figure 1

The electron transport in the mitochondrial respiratory chain and the production of ROS. Complexes I–IV are located in the mitochondrial inner membrane. First, complexes I and II can accept electrons from NADPH and succinic acid and then transport them to coenzyme Q (CoQ), while at the same time, they can pump out protons. Then, complex III can transfer electrons from CoQ to cytochrome C (Cyt c). Finally, complex IV sends electrons to O₂, producing H₂O. During this process, a proton gradient is formed, which promotes the synthesis of ATP. If complex III cannot receive electrons from CoQ, the electrons would be accepted by O₂, which could produce ROS and result in oxidative stress.