AJP - Regulatory, Integrative and Comparative Physiology, Vol 258, Issue 3 783-R787, Copyright © 1990 by American Physiological Society
Cerebrospinal fluid pressure in conscious rats during prostaglandin E1 fever
T. J. Malkinson, K. E. Cooper and W. L. Veale
Department of Medical Physiology, Faculty of Medicine, University of Calgary, Alberta, Canada.
Intraperitoneal body temperature was monitored from groups of 10 conscious
adult male Wistar rats. The daily body temperature rhythm was determined,
and an intraperitoneal body temperature dose response relationship was
established for prostaglandin E1 (PGE1) delivered into a lateral cerebral
ventricle (LCV). Cerebrospinal fluid pressure was measured by direct
cannulation of a LCV. Heart rate, arterial and central venous blood
pressure, and blood gases were also measured in groups of 10 animals. It
was found that there was a daily rhythm in intraperitoneal body temperature
that was higher at night than during the day but stable between 0800 and
1600 h. A significant temperature dose (20-2,000 ng)-response relationship
was established for administration of PGE1 into the LCV. Cerebrospinal
fluid pressure when measured from the LCV increased significantly during
the "chill" phase of the PGE1-induced fever. Carotid arterial blood
pressure also significantly increased at this time as did central venous
pressure, particularly so with vigorous shivering. There was a significant
fall in arterial CO2 partial pressure, a slight rise in pH, and no change
in arterial O2 partial pressure. These data support the hypothesis that a
significant increase in cerebrospinal fluid pressure occurs during the
chill phase of a PGE1-induced fever in the conscious rat.
