Effect of Vitamin E on the Blood-brain Barrier Permeability in Aged Rats with Ptz-induced Convulsions

The effect of vitamin E on the blood-brain barrier (BBB) permeability was studied under conditions of pentylenetetrazole (PTZ)-induced convulsions in aged (23to 24-month-old) male albino rats; Evans Blue was used as a tracer. The BBB permeability was found to considerably increase in rats with PTZ-evoked seizures; the Evans Blue contents in the left and right hemispheres and cerebellum + brainstem region were significantly higher than those in the control. Vitamin E used in the dose of 70 mg/kg exerted practically no beneficial effect on the increased BBB permeability in rats with seizures, while a greater dose of vitamin E (700 mg/kg) exerted a significant protective effect, especially with respect to the cerebellum + brainstem regions (P < 0.01). The seizure-related rise in the arterial blood pressure was also smaller in the latter experimental group. Thus, our observations confirm the importance of the dose of vitamin E as a protective factor for the BBB permeability and demonstrate that the dose dependence of this antioxidant in aged animals differs from that in younger organisms.