Temperature dependence of ethanol depression in rats

Abstract

The relationship between ambient temperature, body temperature, and brain sensitivity to ethanol was investigated in rats. Drug naive male Long Evans rats were injected IP with a hypnotic dose of ethanol (2.75 g/kg, 20% w/v). Immediately after injection, separate groups were exposed to one of five ambient temperatures from 12 to 34 degrees C. Ambient temperature significantly affected wake-up rectal temperature, sleep-time, and wake-up brain ethanol concentration. Sleep-times in individual rats increased 387% (from 24.0 min at 12 degrees C to 116.8 min at 34 degrees C) and wake-up brain ethanol concentrations decreased 79% (from 3.6 mg/g at 12 degrees C to 2.3 mg/g at 34 degrees C) as body temperatures increased from 35 to 41 degrees C. In addition, wake-up rectal temperatures were significantly, positively correlated with sleep-times (r = 0.32, P less than 0.05) and significantly, negatively correlated with wake-up brain ethanol concentrations (r = -0.49, P less than 0.01), further suggesting that brain sensitivity to ethanol increases as body temperature increases. These results are consistent with previous findings in mice, fit membrane perturbation theories of anesthesia, and indicate that temperature dependence of ethanol sensitivity is a general phenomenon extending across species. In conjunction with previous findings, the results also suggest that body temperature during intoxication may participate in mediating species differences in ethanol sensitivity.

Role of hypothermia in ethanol-induced conditioned taste aversion

“…Alkana and his colleagues have noted a positive correlation between post-ethanol ambient temperature and the time required to regain the righting reflex (e.g., Alkana et al 1985;Finn et al 1986). Based on the inverse relationship between sleep-time and wake-up brain ethanol concentration, these investigators argue that changes in body temperature produced by manipulation of ambient temperature alter brain sensitivity to ethanol's depressant effects (Finn et al 1986). The implications of this suggestion for our analysis of ambient temperature effect on ethanol-induced taste aversion are not immediately clear.…”

Impaired neuromuscular function by conjoint actions of organophosphorus insecticide metabolites omethoate and cyclohexanol with implications for treatment of respiratory failure

“…Experiments in rodents suggest that the lethality of alcohols, such as ethanol, is temperature dependent [50,51]. We therefore asked whether reducing core temperature would alleviate neuromuscular block following infusion with cyclohexanol (500 mg kg À1 ).…”

An ontogenetic comparison of ethanol-mediated taste aversion learning and ethanol-induced hypothermia in preweanling rats.

“…Animals exhibit hypothermia if maintained at ambient temperatures below normal body temperature after ethanol administration, whereas those maintained in elevated ambient temperatures experience hyperthermia. Others (Ferko & Bobyock, 1978;Finn, Boone, & Alkana, 1986;Freund, 1973;Gordon & Stead, 1988;Pohorecky & Rizek, 1981) have also reported ethanol's dose-dependent poikilothermic effect on temperature regulation in rodents. Cunningham, Hawks, and Niehus (1988) hypothesized that hypothermia might potentiate the strength of ethanol-mediated conditioned taste aversions.…”