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 (Tc) from undisturbed animals at an ambient temperature (Ta) of 27 degrees C indicated Tc was similar for both strains during active (approximately 38.0 degrees C) and inactive (approximately 36.7 degrees C) periods. Ethanol-injections of 1.5, 2.5, 3.5, and 4.5 g/kg in an environment where Ta rose and fell at 6-min intervals, reaching extremes of 14 and 42 degrees C, produced dose-dependent falls in Tc for both strains. The changes in Ta produced fluctuations in Tc under all conditions. The amplitude of these fluctuations in Tc was used as a measure of physiological disruption. Dose-dependent increases in disruption were found for both strains. At a constant 26 degrees C Ta, 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.