Baker yeast-induced fever in young rats: characterization and validation of an animal model for antipyretics screening.
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.
Tomazetti
Jorgete
J
Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, RS, Brazil.
Avila
Daiana Silva
DS
Ferreira
Ana Paula Oliveira
AP
Martins
Juliana Saibt
JS
Souza
Fabiane Rosa
FR
Royer
Carine
C
Rubin
Maribel Antonello
MA
Oliveira
Marlí Redin
MR
Bonacorso
Hélio Gauze
HG
Martins
Marcos Antônio Pinto
MA
Zanatta
Nilo
N
Mello
Carlos Fernando
CF
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
D018712:Analgesics, Non-Narcotic