Vitamin A and Retinoids as Mitochondrial Toxicants

Figure 1

A schematic diagram summarizing the effects of in vivo vitamin A supplementation on mitochondrial function regarding the mitochondrial electron transfer chain (METC) enzyme activity. Mitochondrial dysfunction may lead to increased production through electron leakage and partial reduction of O₂. Mn-SOD converts to H₂O₂ and, together with MAO, favors an increase in the levels of H₂O₂ in different cell types (please see text for details). H₂O₂ is able to react with iron ions generating (the most powerful ROS) through Fenton chemistry reaction (not shown), for example, leading to widespread redox disturbances.