Temperature dependence of ethanol depression: linear models in male and female mice

The relationship between body temperature and ethanol sensitivity was studied in male and female mice. Age-matched drug-naive mice of both sexes were injected with 3.6 g/kg ethanol (20% w/v) and placed into a chamber kept at one of 8 designated temperatures from 13 to 36 degrees C. In both sexes, wake-up rectal temperatures were significantly, positively correlated with chamber temperatures and sleep-times and were significantly, negatively correlated with wake-up brain and blood ethanol concentrations. Linear regression analyses indicated that wake-up temperature accounted for up to 71% of the variability in sleep-times and wake-up ethanol concentrations in these mice. Similar relationships were found when the change in body temperature from baseline (delta T) was substituted for wake-up rectal temperature. Adding body weights and baseline temperatures did not improve the predictive ability of linear models based on wake-up rectal temperature alone. The results support the contention that body temperature represents an important determinant of ethanol sensitivity in both sexes. These findings provide additional evidence that ethanol sensitivity varies with body temperature in accordance with membrane perturbation theories of anesthesia.