Ethanol disrupts and decreases the regulated body temperature differentially in C57BL/6J and DBA/2J mice

Two inbred mouse strains, C57BL/6J (B6) and DBA/2J (D2), were evaluated for effects of ethanol on thermoregulation. Continuous recording of core temperature (T(c)) from undisturbed animals at an ambient temperature (T(a)) of 27°C indicated T(c) was similar for both strains during active (~38.0°C) and inactive (~36.7°C) periods. Ethanol injections of 1.5, 2.5, 3.5, and 4.5 g/kg in an environment where T(a) rose and fell at 6-min intervals, reaching extremes of 14 and 42°C, produced dose-dependent falls in T(c) for both strains. The changes in T(a) produced fluctuations in T(c) under all conditions. The amplitude of these fluctuations in T(c) was used as a measure of physiological disruption. Dose-dependent increases in disruption were found for both strains. At a constant 26°C T(a), ethanol produced dose- related increases in tail temperature. Responses after ethanol administration were different for B6 and D2 mice. The results indicate regulated temperature is similar for B6 and D2 strains. Regulated temperature is decreased more by ethanol for B6 mice, whereas disruption of thermoregulation by ethanol is greater for D2 mice.