[Ethanol-induced discriminative stimulus properties in inbred rats with reference to aspirin, indomethacin and...

It is known that ethanol (EtOH) possesses discriminative stimulus (DS) effects, but there has been no report on the effects of aspirin, indomethacin and desipramine on the DS properties of EtOH. Lewis (LEW) and Fischer 344 (F344) rats weighing approximately 80% of free-fed animals were used. In the training process, EtOH (600 and 1200 mg/kg) or saline was administered i.p. once a day 5 min prior to beginning of the session according to the following sequence: EtOH-EtOH-saline-saline, under a fixed ratio ten (FR10) schedule. Discriminative test was performed in each animal after the discriminative response had achieved both the two criteria: (1) First Food Pellet (FFP) was below 12 responses and (2) the correct response rate was above 80%. There was no difference in session number to get to the criteria in the discrimination process between LEW and F344. Pentobarbital (PBA) well generalized to EtOH in both strains. The EtOH dose for 50% correct responses (FD50) was lower in F344 than in LEW. However, the ED50 for PBA was lower in LEW than in F344. There may be differences in sensitivity to EtOH and PBA. Dose response curve was not affected by pretreatment with aspirin, indomethacin and desipramine. These results suggest that aspirin, indomethacin and desipramine may not markedly affect in EtOH discriminative stimulus effects in LEW and F344 rats.