Methylmercury and Oxidative Stress
ROS (reactive oxygen species) are generally very small molecules and are highly reactive due to the presence of unpaired valence shell electrons. ROS form as a natural by-product of the normal oxygen metabolism and have important roles in cell signaling. These molecules are generated continuously during oxidative metabolism and consist of inorganic molecules, such as superoxide radical anion (O2 −), hydrogen peroxide (H2O2), hydroxyl radicals (OH−), as well as organic molecules such as alkoxyl and peroxyl radicals (Schulz et al. 2000). Some evidences suggest that the disturbance in the balance between oxidative and reductive cell processes is involved in the pathogenesis of many neurodegenerative conditions such as Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and Parkinson’s disease. Other conditions such as autoimmune and inflammatory diseases, cancer, and diabetes mellitus also seemed to be related to this disturbance (Schulz et al. 2000).