Physical dependence on ethanol: Rate of ethanol clearance from the blood and effect of ethanol on body temperature in rats

Abstract

An inhalation procedure for the administration of ethanol without the use of pyrazole was employed to produce physical dependence on ethanol in rats. A reduction in body temperature was noted at the latter part of the induction phase and in the early hours of withdrawal. In the withdrawal phase the animals experienced convulsions on handling and sponataneous signs of withdrawal. To investigate the rates of ethanol clearance from the blood po and ip routes of ethanol administration were used. A significant enhancement of the rate of ethanol disappearance from the blood was measured in the animals at 48 hr following 10 days of ethanol exposure. Also at this 48-hr time period the usual hypothermic response to ethanol administration was lost in these animals as compared to a control group and to animals receiving ethanol ip, at 7 days after exposure to ethanol vapor. The data indicated that the loss of hypothermic effect from ethanol might be a factor in the increased rate of ethanol clearance. However, in studying the rate of ethanol disappearance from the blood in nondependent animals at 34°C which prevented hypothermia, there was no difference in the rates of ethanol clearance as compared to controls at 23.5°C where the hypothermic effect from ethanol was present. It appears that body temperature does not play a role in the observed acceleration of ethanol clearance from the blood in animals which have undergone withdrawal.