Effect of pretreatment with vitamin E or diazepam on brain metabolism of stressed rats.

The effect of vitamin E (VE) or diazepam (DZ) pretreatment on some carbohydrate metabolic aspects in the brains of stressed rats was studied. DZ and VE were given i.p. at doses of 5 mg/kg body wt for 6 days prior to subjecting the animals to single swimming stress (SSS). Pretreatment of the rats with DZ or VE diminished the stress-induced increases in plasma corticosterone and glucose levels and reversed the decrease due to stress on brain ATP, glucose, glycogen and pyruvate contents. The increase in brain ADP and lactate was brought back to levels which approached the pre-stressed values. Moreover, DZ and VE pretreatments helped in attenuating the stress-induced alteration in brain mitochondrial and cytosolic hexokinase as well as sodium, potassium adenosine triphosphatase (Na+,K(+)-ATPase) activities. The change in these metabolic parameters produced by VE pre-treatment was less than that exhibited by DZ. The effects of VE were explained in light of its antioxidant property in preventing the free radical production and lipid peroxide formation which are important factors in the pathogenesis of stress.