AJP - Regulatory, Integrative and Comparative Physiology, Vol 267, Issue 4 929-R934, Copyright © 1994 by American Physiological Society
Temperature regulation in mice during withdrawal from ethanol dependence
L. I. Crawshaw, C. S. O'Connor, J. C. Crabbe and D. L. Hayteas
Department of Biology and Environmental Science Program, Portland State University 97207.
Temperature regulation during withdrawal from ethanol dependence was
studied in mice. Dependence was induced utilizing ethanol vapor inhalation
combined with injections of pyrazole, an alcohol dehydrogenase inhibitor.
One control group received vehicle (0.9% NaCl); another received pyrazole
(68.1 mg/kg) in vehicle. During withdrawal, mice were placed in a thermal
gradient, with core temperature (Tc) and preferred temperature (Tpref)
continuously recorded for 26 h. During the period of maximal withdrawal
severity (4-10 h after removal from ethanol vapor), the withdrawal group
was more active than controls. Withdrawal group Tc [36.4 +/- 0.1 (SE)
degrees C] was similar to that of NaCl (36.2 +/- 0.1 degrees C) and
pyrazole (36.3 +/- 0.2 degrees C) controls. Withdrawal group Tpref (30.5
+/- 0.5 degrees C) was significantly lower than either NaCl (33.5 +/- 0.3
degrees C) or pyrazole (32.9 +/- 0.5 degrees C) controls. Analysis of
covariance with activity as covariate indicated that the difference between
Tc and Tpref was greater for the withdrawal group and was due to more than
increased activity. Mice withdrawing at constant temperature (29.5 degrees
C) did not show Tc different from that of controls. These results support
the conclusion that regulated body temperature is not altered during
withdrawal. We propose that the lower Tpref of withdrawing mice represents
a means of dissipating excess heat that is partly generated by the
hypermetabolic state accompanying withdrawal from ethanol dependence.
