Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/196446
Type: Artigo
Title: The effects of restraint stress on nociceptive responses induced by formalin injected in rat's TMJ
Author: Gameiro, Gustavo Hauber
Andrade, Annicele da Silva
de Castro, Margaret
Pereira, Lígia Ferrinho
Tambeli, Cláudia Herrera
Veiga, Maria Cecília Ferraz de Arruda
Abstract: It has been reported that stress can alter nociception from superficial tissues, such as skin and subcutaneous region. However, the influence of stress on an experimental deep nociception model is not understood. In this study, the temporomandibular joint (TMJ) formalin test was used to evaluate the effects of acute and chronic restraint stress on nociceptive responses in rats. Animals were initially submitted to one session of acute restraint stress (1 h) or exposed to chronic stress (40 days-1 h/day). Then, animals were killed immediately to collect blood for hormonal determinations by radioimmunoassay, or submitted to the TMJ formalin test to evaluate nociception. Rats submitted to acute restraint presented a performance similar to unstressed controls in the TMJ formalin test, whereas chronically stressed rats showed an increase in nociceptive responses. After 40 days of restraint, morphine was injected i.p. (1, 5 mg/kg or saline). The stressed rats displayed decreased morphine effects on nociception compared to unstressed controls. These findings suggest that repeated stress can produce hyperalgesia, which is, at least in part, due to alterations in the activity of opioid systems. This model may help elucidate the underlying neural mechanisms that mediate the effects of repeated stress on orofacial pain.
It has been reported that stress can alter nociception from superficial tissues, such as skin and subcutaneous region. However, the influence of stress on an experimental deep nociception model is not understood. In this study, the temporomandibular joint (TMJ) formalin test was used to evaluate the effects of acute and chronic restraint stress on nociceptive responses in rats. Animals were initially submitted to one session of acute restraint stress (1 h) or exposed to chronic stress (40 days—1 h/day). Then, animals were killed immediately to collect blood for hormonal determinations by radioimmunoassay, or submitted to the TMJ formalin test to evaluate nociception. Rats submitted to acute restraint presented a performance similar to unstressed controls in the TMJ formalin test, whereas chronically stressed rats showed an increase in nociceptive responses. After 40 days of restraint, morphine was injected i.p. (1, 5 mg/kg or saline). The stressed rats displayed decreased morphine effects on nociception compared to unstressed controls. These findings suggest that repeated stress can produce hyperalgesia, which is, at least in part, due to alterations in the activity of opioid systems. This model may help elucidate the underlying neural mechanisms that mediate the effects of repeated stress on orofacial pain
Subject: Estresse
Hiperagelsia
Articulação temporomandibular
Nociceptividade
Country: Estados Unidos
Editor: Elsevier
Citation: Pharmacology, Biochemistry, And Behavior. v. 82, n. 2, p. 338-44, 2005-Oct.
Rights: fechado
Identifier DOI: 10.1016/j.pbb.2005.09.003
Address: https://www.sciencedirect.com/science/article/pii/S0091305705003047?via%3Dihub
Date Issue: 2005
Appears in Collections:FOP - Artigos e Outros Documentos

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