title: Baker yeast-induced fever in young rats: characterization and validation of an animal model for antipyretics screening.
abstract: In this study we describe a low-cost and reliable method for inducing fever in young male rats (28-30 days of age, 75-90 g), which seems suitable for the screening of new antipyretics. The effects of temperature measuring procedure-induced stress on the basal rectal temperature and on Baker yeast-induced hyperthermia was assessed. Rectal temperature (T) was recorded every hour for 12 h (07:00-19:00 h) with a lubricated thermistor probe. The animals were injected intraperitoneally with baker yeast (0.25, 0.135, 0.05 g/kg) or the equivalent volume of saline at 7:00 h. The administration of 0.135 g/kg baker yeast induced a sustained increase in rectal temperature for 4 h. Classical (dipyrone and acetaminophen) and novel (MPCA and FPCA) antipyretics, at doses that had no effect per se, reverted baker yeast-induced fever. The method presented induces a clear-cut fever, which is reverted by antipyretics commonly used in human beings and selected novel antipyretics in small animals. The method also allows antipyretic evaluation with low amount of drugs, due to the use of small animals and to the small variability of the pyretic response, which ultimately causes a significant reduction in the number of animals necessary for antipyretic evaluation. Therefore, this study describes an animal model of fever that is not only advantageous from the economical and technical point of view, but that also bears ethical concerns.
authors.affiliation: Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, RS, Brazil.
authors.forename: Jorgete
authors.initials: J
authors.lastname: Tomazetti
authors.forename: Daiana Silva
authors.initials: DS
authors.lastname: Avila
authors.forename: Ana Paula Oliveira
authors.initials: AP
authors.lastname: Ferreira
authors.forename: Juliana Saibt
authors.initials: JS
authors.lastname: Martins
authors.forename: Fabiane Rosa
authors.initials: FR
authors.lastname: Souza
authors.forename: Carine
authors.initials: C
authors.lastname: Royer
authors.forename: Maribel Antonello
authors.initials: MA
authors.lastname: Rubin
authors.forename: Marlí Redin
authors.initials: MR
authors.lastname: Oliveira
authors.forename: Hélio Gauze
authors.initials: HG
authors.lastname: Bonacorso
authors.forename: Marcos Antônio Pinto
authors.initials: MA
authors.lastname: Martins
authors.forename: Nilo
authors.initials: N
authors.lastname: Zanatta
authors.forename: Carlos Fernando
authors.initials: CF
authors.lastname: Mello
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001831:Body Temperature / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005334:Fever / Q000188:drug therapy* / Q000382:microbiology; D006979:Hyperthermia, Induced / Q000379:methods; D008297:Male; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000472:pathogenicity*; D013997:Time Factors
chemical_list: D018712:Analgesics, Non-Narcotic