The possible role of nitric oxide and impaired mitochondrial function in ataxia due to severe vitamin E deficiency

Ataxia due to prolonged vitamin E (RRR-alpha-tocopherol) deficiency still remains the only human neurodegenerative disorder that can be positively attributed to insufficient levels of an essential antioxidant. In affected nerve cells during vitamin E deficiency there is an increase in peroxidation of mitochondrial membranes and a progressive reduction in respiration-dependent axonal transport processes, ultimately resulting in cell death. The possibility of inhibition of electron transport and the increased generation of oxygen radicals that may arise due to prolonged exposure to the toxic nitric oxide radical within mitochondria of vitamin E-deficient neurones is discussed as a pathway to nerve cell death that is characteristically seen in the syndrome.