Abstract

The in vivo and in vitro effects of d-amphetamine were assessed in rats after subacute (24 hr) administration of ethanol vapor (28 mg/l). Forty-eight hours after the termination of ethanol vapor inhalation, when the animals were tolerant to the hypothermic effect of ethanol, a decreased hypothermic response to d-amphetamine was detected, suggesting that functional changes in dopaminergic activity might be associated with ethanol tolerance. The hyperthermic effect of d-amphetamine was similar in the ethanol-tolerant and control animals. The d-amphetamine-stimulated release of [3H]dopamine from crude synaptosomal (P2) fractions of striatum was nearly abolished immediately after subacute ethanol administration. Samples prepared from ethanol-tolerant animals released less [3H]dopamine in response to d-amphetamine perfusion compared to samples prepared from control animals when tested 48 hr after ethanol vapor exposure. Subacute ethanol administration appears to produce long-acting changes in d-amphetamine-sensitive dopaminergic mechanisms.