Ascorbic acid effect on ethanol sensitivity via possible dopaminergic mediation.

Mice were injected with 0, 107, 215, 430, or 1720 mg/kg of ascorbic acid. Thirty min later they were tested for ethanol (3.5 g/kg) induced sleep time. Brain ethanol levels were determined upon awakening. Another group of mice were tested for apomorphine (3 mg/kg) induced locomotor activity also 30 min after ascorbic acid injection. Ascorbic acid in doses above 215 mg/kg augmented ethanol sleep time up to 210% at the highest doses, the increase being significant from 430 mg/kg. Brain ethanol levels upon awakening were reduced by ascorbic acid treatment; this reduction was significant at 1720 mg/kg dose. Ascorbic acid decreased apomorphine-induced locomotor activity in a dose response manner that paralleled the ascorbic acid increase of ethanol sleep time. At the highest dose of ascorbic acid, apomorphine-induced locomotor activity was completely eliminated. It is suggested that ascorbic acid increases brain sensitivity to ethanol by lowering the activity of dopamine receptors.