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Centrally acting vasopressin contributes to endotoxin tolerance
1Department of Physiology, Faculty of Medicine, University of British Columbia, Vancouver, Canada.
The American Journal of Physiology
|February 1, 1990
Summary
Arginine vasopressin (AVP) may suppress fever. Blocking AVP V1 receptors in the brain enhanced fever responses to endotoxin in tolerant rats, suggesting AVP
Area of Science:
- Neuroscience
- Immunology
- Pharmacology
Background:
- Repeated endotoxin administration induces pyrogenic tolerance.
- Arginine vasopressin (AVP) is linked to natural fever suppression.
- AVP's role in endotoxin tolerance is not fully understood.
Purpose of the Study:
- To investigate the role of AVP in pyrogenic tolerance to endotoxin.
- To determine if central AVP acts as an endogenous antipyretic during endotoxin tolerance.
Main Methods:
- Rats received daily intravenous injections of Escherichia coli endotoxin to induce tolerance.
- AVP V1-receptor and V2-receptor antagonists were administered into the ventral septal area (VSA).
- Thermoregulatory responses to subsequent endotoxin challenges were measured.
Main Results:
- Bilateral VSA administration of an AVP V1 antagonist dose-dependently enhanced the thermoregulatory response to endotoxin in tolerant rats.
- An AVP V2 antagonist had no effect on endotoxin tolerance.
- Neither saline nor V1 antagonist alone affected core body temperature.
Conclusions:
- AVP acts as an endogenous antipyretic within the VSA during fever.
- Centrally acting vasopressin plays a role in pyrogenic tolerance to endotoxin.