Effects on neural function of repleting vitamin E-deficient rats with alpha-tocopherol.

A severe and chronic deficiency of vitamin E (alpha-tocopherol) is associated with a characteristic neurological syndrome with typical "clinical," neuropathological, and electrophysiological abnormalities in both humans and experimental animals. Repletion of vitamin E-deficient human subjects with alpha-tocopherol typically halts the progression of the neural signs and symptoms, and in some cases, can result in objective improvement. Electrophysiological parameters provide an objective measure of neural and visual function and improvement of some of these measures has been reported after repletion with vitamin E in humans. In this longitudinal study, the effects of repleting rats with a diet containing 36 mg/kg all-rac-alpha-tocopheryl acetate for 20 wk after they had been receiving a vitamin E-deficient diet for 38 wk was studied. We report significant improvements in growth and a number of electrophysiological parameters of both neural and visual function after repletion. These results confirm the validity of the vitamin E-deficient rat as a model of vitamin E deficiency in humans.