Role of protein oxidation in aging and in age-associated neurodegenerative diseases.

Aging and age-associated neurodegenerative diseases have been proposed to be the result of changes in a in anti-oxidant status and in the production of reactive oxygen species. Studies in humans have demonstrated a significant increase in oxidized protein from brains of neurological normals and from individuals with different neurological diseases (Alzheimer's, Parkinson's and Huntington's Disease). Preclinical models of these conditions and of cerebral ischemia demonstrate the primary role of protein oxidation in the initial steps of these neurodegenerative diseases. Aging is a risk factor in the development of these diseases and is also associated with a decrease in the anti-oxidant defense systems of the brain. It is proposed that free radicals play a primary role in the initiation of those biochemical events that ultimately lead to the death of the neuron.