Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2007-12-18
pubmed:abstractText
The exact mechanism of the masseter muscle pain recognized as a prominent symptom in temporomandibular disorders remains unclear, although it is clinically known that excessive muscular contraction causes tenderness in masseter muscles. It has been demonstrated that P2X3 receptors (P2X3Rs) in sensory neurons play a role in pain signaling from the periphery. We determined the role of P2X(3)R on pressure pain and mechanical hyperalgesia in a newly developed rat model of masseter muscle pain. The pain in the masseter muscle was assessed by the pressure pain threshold (PPT), which was defined as the amount of pressure required to induce head flinching. In naive animals, systemic treatment with morphine was associated with increase of PPTs. Changes in PPTs were examined after administration of P2XR agonists or antagonists into the masseter muscle. The masseter muscle injection of alpha,beta-meATP (P2X(1,3,2/3)R-specific agonist) induced a significantly greater behavioral response than its vehicle. This enhanced response was completely blocked by the co-application of alpha,beta-meATP with PPADS (P2X(1,2,3,5,1/5,2/3)R-specific antagonist). Excessive contraction in masseter muscle was produced by electrical stimulation. The exerted masseter muscles showed a significant reduction in PPTs indicating the induction of mechanical hyperalgesia of the muscle. Moreover, administration of PPADS to the exerted masseter muscles produced a complete recovery of reducing PPT. Immunohistochemically, the number of P2X3R-positive neurons innervating the masseter muscles increased in the excessively contracted condition in trigeminal ganglia. Our results suggested that P2X3R plays an important role in pressure pain and mechanical hyperalgesia in masseter muscle caused by excessive muscular contraction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1872-6623
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
134
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
148-57
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Involvement of ATP and its receptors on nociception in rat model of masseter muscle pain.
pubmed:affiliation
Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan.
pubmed:publicationType
Journal Article, Comparative Study