AJP - Regulatory, Integrative and Comparative Physiology, Vol 254, Issue 3 513-R517, Copyright © 1988 by American Physiological Society
Enhanced fever following castration: possible involvement of brain arginine vasopressin
Q. J. Pittman, T. J. Malkinson, N. W. Kasting and W. L. Veale
Department of Medical Physiology, University of Calgary, Alberta, Canada.
Arginine vasopressin (AVP) is thought to act as an antipyretic in the
ventral-septal area (VSA) of the brain. As AVP content of this area has
been shown to be virtually eliminated following long-term castration, we
have tested the hypothesis that castrated rats would display enhanced
fevers. Four months after castration (or sham castration), male Wistar rats
were given prostaglandin E1 (200 ng), purified interleukin 1 (25 U), or
saline (5 microliters) into a lateral cerebral ventricle. Castrated rats
displayed fevers of longer duration, reflected as significantly enhanced
thermal indexes, than did age-matched sham-operated controls. Castrated
rats also were less able to defend their body temperatures to ambient heat
stress but not to ambient cold. AVP content of VSA and lateral septum, but
not of hippocampus, of castrated rats was significantly reduced; oxytocin
content of the three areas was unchanged following castration. These data
support earlier studies concerning effects of castration on septal AVP
content and are consistent with the possibility that AVP is an antipyretic
in the VSA of the rat.
