Vagotomy does not inhibit high dose lipopolysaccharide-induced interleukin-1 beta immunoreactivity in rat brain and pituitary gland

In the present study, we examined whether the vagus nerve is involved in me diating lipopolysaccharide (LPS)-induced appearance of IL-1 beta immunoreac tive cells in the brain and pituitary gland. Rats were either sham-operated or subjected to subdiaphragmatic vagotomy. Four weeks later, pyrogen free saline or 400 mu g/kg LPS was administered to the rats intraperitoneally. F our and 8 h later, the animals were intracardially perfused with 4% parafor maldehyde and tissues were prepared for IL-1 beta immunocytochemistry. IL-1 beta positive cells were observed at both time-intervals after LPS adminis tration in the choroid plexus, meninges, circumventricular organs and pitui tary gland of both sham-operated and vagotomized rats. We conclude that und er the conditions studied, the vagus nerve does not mediate LPS-induced app earance of IL-1 beta in the rat brain and pituitary gland. (C) 2000 Elsevie r Science Ireland Ltd. All rights reserved.