title: Fever induction by localized subcutaneous inflammation in guinea pigs: the role of cytokines and prostaglandins.
abstract: In guinea pigs, dose-dependent febrile responses can be induced by injection of a high (100 micro g/kg) or low (10 micro g/kg) dose of bacterial lipopolysaccharide (LPS) into artificial subcutaneously implanted Teflon chambers. In this fever model, LPS does not enter the systemic circulation from the site of localized tissue inflammation in considerable amounts but causes a local induction of the proinflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6), which can be measured in lavage fluid collected from the chamber area. Only in response to the high LPS dose, small traces of TNF are measurable in blood plasma. A moderate increase of circulating IL-6 occurs in response to administration of both LPS doses. To investigate the putative roles of TNF and prostaglandins in this fever model, a neutralizing TNF binding protein (TNF-bp) or a nonselective inhibitor of cyclooxygenases (diclofenac) was injected along with the high or low dose of LPS into the subcutaneous chamber. In control groups, both doses of LPS were administered into the chamber along with the respective vehicles for the applied drugs. The fever response to the high LPS dose remained unimpaired by treatment with TNF-bp despite an effective neutralization of bioactive TNF in the inflamed tissue area. In response to the low LPS dose, there was an accelerated defervescence under the influence of TNF-bp. Blockade of prostaglandin formation with diclofenac completely abolished fever in response to both LPS doses. In conclusion, prostaglandins seem to be essential components for the manifestation of fever in this model.
authors.affiliation: Institut für Veterinär-Physiologie, Justus-Liebig-Universität, D-35392 Giessen, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: Ross
authors.forename: Thomas
authors.initials: T
authors.lastname: Hübschle
authors.forename: Ulrich
authors.initials: U
authors.lastname: Pehl
authors.forename: Hans-Albert
authors.initials: HA
authors.lastname: Braun
authors.forename: Karlheinz
authors.initials: K
authors.lastname: Voigt
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Gerstberger
authors.forename: Joachim
authors.initials: J
authors.lastname: Roth
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000008:administration & dosage; D016207:Cytokines / Q000378:metabolism*; D004008:Diclofenac / Q000008:administration & dosage; D004338:Drug Combinations; D003875:Drug Eruptions / Q000150:complications* / Q000378:metabolism*; D005334:Fever / Q000209:etiology* / Q000503:physiopathology; D006168:Guinea Pigs; D007279:Injections, Subcutaneous; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000097:blood; D011453:Prostaglandins / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D053319:Tumor Necrosis Factor Decoy Receptors
chemical_list: D002352:Carrier Proteins; D016861:Cyclooxygenase Inhibitors; D016207:Cytokines; D004338:Drug Combinations; D008070:Lipopolysaccharides; D011453:Prostaglandins; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D053319:Tumor Necrosis Factor Decoy Receptors; D004008:Diclofenac; C069521:recombinant human tumor necrosis factor-binding protein-1