Circadian Variation in Host Defense.
Abstract
We have been monitoring the body temperature and relative activity of up to 24 rats at a time using a recently developed biotelemetry system (The Dataquest III; Mini-Mitter Company). Each cage is maintained in a constant temperature chamber at 27 C and is on a 12:12 hour light-dark cycle. In the process of testing the versatility of this system and obtaining pilot data we have generated data for two manuscripts (1) Hyperthermia induced by open-field stress is blocked by salicylate, Physiology and Behavior, (2) Selection of cage size by Sprague-Dawley rats. Data directly relevant to the ultimate goal of the research include the following: a. We have established a dose of sodium salicylate which will block the circadian rise in body temperature, and b. We have established the normal circadian variation in activity for rats maintained on a 12:12 light-dark cycle. The administration of an antipyretic dose of sodium salicylate to rats in the late afternoon resulted in significant attenuation of the rise in body temperature normally observed at night; the drug had no effect on activity. Administration of this same dose of sodium salicylate to rats during the morning hours had no effect on body temperature or on activity. Since antipyretic drugs are thought to act by returning an elevated thermoregulatory set-point to normal, these data suggest to us that the rise in temperature observed at night in rats is a true fever, perhaps induced by interleukin-1 (IL-1).
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 18, 1985
- Accession Number
- ADA161702
Entities
People
- Matthew J. Kluger
Organizations
- University of Michigan