The effect of stress on tolerance to ethanol in rats.

In male rats given 6.0-8.0 g/kg of ethanol/day via gastric intubation, footshock stress accelerated the development of functional tolerance to ethanol (ethanol-induced hypothermia and motor impairment on a dowel task). A primarily psychological stressor (observing other rats that were being shocked) may have retarded tolerance development as subjects in this condition showed no development of functional tolerance. Nonstressed subjects developed tolerance more slowly and required a higher daily dose of ethanol to develop tolerance than shock stressed subjects. Conditioned responses to the drug administration procedure did not appear to play a role in the development of tolerance.