title: Influence of pentoxifylline on fevers induced by bacterial lipopolysaccharide and tumor necrosis factor-alpha in guinea pigs.
abstract: In guinea pigs intraperitoneal (i.p.) injections of 50 mg/kg pentoxifylline had no influence on abdominal temperature while higher doses of pentoxifylline caused a hypothermic response lasting for 2-3 h. Administration of 50 mg/kg pentoxifylline 1 h before intramuscular (i.m.) injections of 20 micrograms/kg bacterial lipopolysaccharide reduced the lipopolysaccharide-induced production of endogenous tumor necrosis factor-alpha (TNF-alpha) by 68%. The second phase of lipopolysaccharide-induced fever was significantly attenuated by pretreatment with 50 mg/kg pentoxifylline, a dose which had, per se, no influence on core temperature of guinea pigs. The thermal response of guinea pigs to administration of exogenous TNF-alpha was not modulated by pretreatment with pentoxifylline. Intra-arterial infusions with 5 micrograms/kg TNF-alpha, a dose which yielded the same circulating TNF bioactivity as i.m. injections of 20 micrograms/kg lipopolysaccharide, induced a biphasic febrile response. The magnitude and duration of TNF-induced fever were the same whether guinea pigs were pretreated with pentoxifylline or with 0.9% saline. The results indicate that endogenous formation of TNF-alpha may contribute to the development of fever induced by lipopolysaccharide, but is not its only mediator, since the first phase of lipopolysaccharide-induced fever was not altered by the blockade of TNF production.
authors.affiliation: Physiologisches Institut am Klinikum, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: J M
authors.initials: JM
authors.lastname: Goldbach
authors.forename: J
authors.initials: J
authors.lastname: Roth
authors.forename: B
authors.initials: B
authors.lastname: Störr
authors.forename: E
authors.initials: E
authors.lastname: Zeisberger
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins; D005334:Fever / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology*; D006168:Guinea Pigs; D007261:Infusions, Intra-Arterial; D007273:Injections, Intramuscular; D007274:Injections, Intraperitoneal; D008297:Male; D010431:Pentoxifylline / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D018712:Analgesics, Non-Narcotic; D004731:Endotoxins; D014409:Tumor Necrosis Factor-alpha; C044101:endotoxin, Escherichia coli; D010431:Pentoxifylline