Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/198439
Type: Artigo de periódico
Title: Peripheral Estradiol Induces Temporomandibular Joint Antinociception In Rats By Activating The Nitric Oxide/cyclic Guanosine Monophosphate Signaling Pathway.
Author: Fávaro-Moreira, N C
Torres-Chávez, K E
Fischer, L
Tambeli, C H
Abstract: Recently, we have reported that high physiological estradiol level during the proestrus phase of the estrous cycle or systemic estradiol administration in ovariectomized rats decreases formalin-induced temporomandibular joint nociception. However, the mechanisms underlying the antinociceptive effect of estradiol are presently unknown. In this study, we used the temporomandibular joint formalin model in rats to investigate whether estradiol decreases nociception by a peripheral non-genomic mechanism, and if so, whether this mechanism is mediated by the activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway and of opioid receptors. The administration of estradiol into the ipsilateral, but not into the contralateral temporomandibular joint significantly reduced formalin-induced temporomandibular joint nociception in ovariectomized and diestrus but not in proestrus females. However, the administration of the estrogen receptor antagonist ICI 182780 into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of serum estradiol in proestrus females, suggesting that the physiological effect of estradiol in nociception is mediated, at least in part, by a peripheral mechanism. The administration of estradiol into the ipisilateral temporomandibular joint did not affect formalin-induced nociception in male rats. The antinociceptive effect of temporomandibular joint estradiol administration in ovariectomized and diestrus females was mimicked by estradiol conjugated with bovine serum albumin, which does not diffuse through the plasma membrane, and was blocked by the estrogen receptor antagonist ICI 182780. The administration of the nitric oxide synthase inhibitor (nitro-l-arginine) or of a guanylate cyclase inhibitor (1H-(1,2,4)-oxadiasolo (4,2-a) quinoxalin-1-one) into the ipsilateral, but not into the contralateral temporomandibular joint blocked the antinociceptive effect of estradiol and of estradiol conjugated with bovine serum albumin, while the opioid receptor antagonist naloxone had no effect. These findings suggest that estradiol decreases temporomandibular joint nociception in female rats through a peripheral non-genomic activation of the nitric oxide-cyclic guanosine monophosphate signaling pathway.
Subject: Analgesics
Animals
Cyclic Gmp
Diestrus
Estradiol
Female
Formaldehyde
Guanylate Cyclase
Male
Nitric Oxide
Nitric Oxide Synthase
Ovariectomy
Pain
Proestrus
Rats
Rats, Wistar
Signal Transduction
Temporomandibular Joint
Citation: Neuroscience. v. 164, n. 2, p. 724-32, 2009-Dec.
Rights: fechado
Identifier DOI: 10.1016/j.neuroscience.2009.08.012
Address: http://www.ncbi.nlm.nih.gov/pubmed/19679171
Date Issue: 2009
Appears in Collections:Unicamp - Artigos e Outros Documentos

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