Importance of the vagus nerve for fever and neutrophil migration induced by intraperitoneal LPS injection.
OBJECTIVE
We investigated the importance of the vagus nerve in fever, neutrophil migration and neutrophilia simultaneously induced by intraperitoneal injection of endotoxin (lipopolysaccharide, LPS) and in terms of the production of pre-formed pyrogenic factor (PFPF) and of the fever induced by this factor.


METHODS
Naïve, sham-operated or subdiaphragmatically vagotomized male Wistar rats received either LPS (i.p. or i.pl.) or PFPF (i.v., i.c.v., i.p.). The number of neutrophils was evaluated in peritoneal or pleural fluid and in blood. Fever was monitored using a rectal probe.


RESULTS
In naïve animals, LPS (0.02-200 microg kg(-1), i.p.) induced dose-related neutrophilia and fever while on neutrophil migration it resulted in a bell-shaped curve. Vagotomy reduced the peritoneal resident cell population (56%), fever (71%) and neutrophil migration (43%) but not the neutrophilia or neutrophil migration to the pleural cavity. Vagotomy did not affect the PFPF production or PFPF-induced fever.


CONCLUSIONS
Vagus nerve integrity is important not only for fever but also for the neutrophil influx to the peritoneal cavity by controlling the number of resident cells in this cavity.
Werner
M F P
MF
Department of Pharmacology, Biological Sciences Section, Federal University of Paraná, PO Box 19031, 81540-970, Curitiba, PR, Brazil.
Fraga
D
D
Melo
M C C
MC
Souza
G E P
GE
Zampronio
A R
AR
D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D001831:Body Temperature / Q000187:drug effects; D005334:Fever / Q000139:chemically induced* / Q000503:physiopathology*; D007202:Indicators and Reagents; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000008:administration & dosage; D008297:Male; D020556:Neutrophil Infiltration / Q000502:physiology*; D010994:Pleura / Q000166:cytology; D051381:Rats; D017208:Rats, Wistar; D014628:Vagotomy; D014630:Vagus Nerve / Q000503:physiopathology*
D007202:Indicators and Reagents; D008070:Lipopolysaccharides