Handling-induced enhancement of alcohol's acute physiological effects.

A mild stressor (handling) exacerbated the acute effects of ethanol on heart rate and body temperature in rats. Although the tachycardia produced by the combination of ethanol and handling appeared to be due to a simple summation of the separate tachycardic effects of each condition, the thermal change represented a nonadditive combination of the separate effects. Specifically, although handling alone produced hyperthermia, it enhanced the hypothermia induced by ethanol. Blood and brain levels of ethanol were not altered by handling. Stress-induced enhancement of critical responses to ethanol may have important implications for the development of tolerance to and dependence on alcohol.