Subdiaphragmatic vagotomy does not block intraperitoneal lipopolysaccharide-induced fever

Auton Neurosci. 2000 Dec 20;85(1-3):83-7. doi: 10.1016/S1566-0702(00)00224-1.


Several recent findings, including the inability of subdiaphragmatic vagotomy to block lipopolysaccharide (LPS)-induced interleukin-1beta (IL-1beta) protein in brain, have made it necessary to reexamine the role of the subdiaphragmatic vagal afferents in immune-to-brain communication. In this study, we examined the effects of intraperitoneal (i.p.) injections of LPS on core body temperature in control and subdiaphragmatically vagotomized rats. Vagotomized and sham-operated male Sprague-Dawley rats were injected i.p. with vehicle (pyrogen-free saline) on the control day and LPS (1, 10 or 50 microg/kg) on the experimental day, and core body temperature was monitored by telemetry for 6 h after the injection. At this time, rats were sacrificed, and serum, liver, and pituitary samples were collected. The i.p. injection of LPS increased core body temperature in both sham-operated and vagotomized rats compared to the saline injection. In addition, LPS significantly increased IL-1beta levels in serum, liver, and pituitary compared to saline-injected controls. There were no significant differences in the magnitude of the fever or in the levels of IL-1beta in serum, liver, or pituitary between sham-operated and vagotomized rats. Thus, the current data indicate that, at the doses tested, subdiaphragmatic vagal afferents are not crucial for i.p. LPS-induced fever. Because several effects of vagotomy have been shown to be dependent on dose, we are currently investigating whether vagal afferents are involved in lower-dose i.p. LPS-induced fever.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain / cytology
  • Brain / immunology
  • Cholecystokinin / pharmacology
  • Diaphragm
  • Dose-Response Relationship, Drug
  • Eating / drug effects
  • Fever / chemically induced
  • Fever / immunology
  • Fever / physiopathology*
  • Injections, Intraperitoneal
  • Interleukin-1 / analysis
  • Interleukin-1 / blood
  • Lipopolysaccharides / pharmacology
  • Liver / chemistry
  • Liver / immunology
  • Male
  • Neuroimmunomodulation / physiology*
  • Pituitary Gland / chemistry
  • Pituitary Gland / immunology
  • Rats
  • Rats, Sprague-Dawley
  • Vagotomy / methods*
  • Vagus Nerve / cytology
  • Vagus Nerve / immunology*
  • Vagus Nerve / surgery


  • Interleukin-1
  • Lipopolysaccharides
  • Cholecystokinin