Brain glutathione peroxidase in neurodegenerative disorders.

Glutathione peroxidase is an enzyme that couples the oxidation of reduced glutathione to the detoxification of peroxides. Alterations in the activity of this component of the glutathione oxygen scavenging system in brain have been reported in several conditions associated with oxidative challenge and/or cellular damage. We measured the activity of glutathione peroxidase in autopsied brain regions of neurologically normal adults and in brain of patients with primary degenerative disorder Alzheimer's type (AD/SDAT), as well as two other neurodegenerative disorders, namely Huntington's disease and striatonigral degeneration. No significant alterations in enzyme activity were observed in morphologically normal or abnormal brain regions. Our results suggest that in the three brain disorders studied, the neuronal cell loss is unlikely to result from reduced activity of brain glutathione peroxidase, and that a significant compensatory increase in this brain enzyme, consequent to the degenerative processes, does not occur.