Studies on the neurobiology of vitamin E (alpha-tocopherol) and some other antioxidant systems in the rat.

To understand why nervous tissue should be particularly affected by severe deficiency of vitamin E, the distribution of vitamin E (alpha-tocopherol) and some other antioxidant systems was investigated. The concentration of vitamin E and the activities of glutathione peroxidase and superoxide dismutase were determined in different regions of the nervous system in male Wistar rats. The cerebral cortex had the highest, and the cerebellum the lowest concentration of alpha-tocopherol (P less than 0.02). Activity of glutathione peroxidase tended to show an inverse relationship to the alpha-tocopherol concentration, whereas superoxide dismutase activity was evenly distributed through the nervous tissue. Vitamin E concentrations were also determined in spinal cord, sciatic and tibial nerves and in epineurial, myelin and non-myelin fractions of the sciatic nerve. Uptake of intravenously injected tritiated alpha-tocopherol was studied after 6 h and found to be greater in brain and peripheral nerve than cervical and thoracic regions of the spinal cord. Uptake of tocopherol varied along the sciatic and tibial nerve, being greatest where the sciatic nerve divided into tibial, sural and common peroneal nerves. This corresponded to an area of increased vasculature which was visualized by an angiographic technique using barium sulphate.