Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
2010-7-1
pubmed:abstractText
Temporomandibular disorders (TMDs) predominantly affect reproductive female patients, with pain the most frequent complaint. Although estrogens are believed to play important roles in TMD pain, the mechanism underlying modulation of TMD pain by estrogens remains largely unknown. Accumulating evidence implies that the hippocampus is involved in sexual dimorphism of pain sensitivity. In this study, we investigated the hippocampal TRPV1 (transient receptor potential vanilloid 1) expression in ovariectomized rats that received 17-beta-estradiol substitution and found that 17-beta-estradiol enhanced the mechanical allodynia of inflamed temporomandibular joint (TMJ) induced by complete Freund's adjuvant. Real-time PCR and immunoblotting demonstrated that TMJ inflammation significantly induced hippocampal TRPV1 expression compared with the control group but failed to induce it in the ovariectomized rats that received no estradiol replacement. In addition, estradiol potentiated TMJ inflammation-induced hippocampal TRPV1 expression in a dose-dependent manner in the ovariectomized rats. In contrast, TRPV1 transcription in amygdala, prefrontal cortex, and thalamus was not affected by TMJ inflammation and estradiol. Immunostaining showed TRPV1 localized in the processes and cytoplasm of pyramidal neurons in CA1-CA3 regions of the hippocampus. Moreover, intrahippocampal injection of TRPV1 antagonists capsazepine and 5'-iodo-resiniferatoxin into the CA1 region of the hippocampus significantly attenuated allodynia of inflamed TMJ in both nonovariectomized and ovariectomized rats that received estradiol replacement. Our results suggested that hippocampal TRPV1 can modulate central pain processing and estradiol may contribute to the sexual dimorphism of TMD pain sensitivity through upregulation of TRPV1 expression in the hippocampus.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
30
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8710-9
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
17-Beta-estradiol enhanced allodynia of inflammatory temporomandibular joint through upregulation of hippocampal TRPV1 in ovariectomized rats.
pubmed:affiliation
Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing 100081, People's Republic of China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't