Capsaicin receptor expression in the rat temporomandibular joint.
Experimentally, temporomandibular joint (TMJ) nerve units respond to capsaicin, which is used clinically to treat TMJ pain. However, the existence of capsaicin receptors in the TMJ has not previously been clearly demonstrated. Immunohistochemical analysis has revealed the presence of transient receptor potential vanilloid subtype 1 (TRPV1) expression in the nerves and synovial lining cells of the TMJ. TRPV1-immunoreactive nerves are distributed in the synovial membrane of the joint capsule and provide branches to the joint compartment. The disc periphery is supplied by TRPV1 nerves that are mostly associated with small arterioles, and occasional nerves penetrate to the synovial lining layer. Double immunofluorescence has shown that many TRPV1-immunoreactive nerves are labeled with neuropeptide calcitonin gene-related peptide, whereas few are labeled with IB4-lectin. The results provide evidence for the presence of TRPV1 in both nerves and synovial lining cells, which might thus be involved in the mechanism of nociception and inflammation in the TMJ.
Ioi
Hideki
H
Department of Orthodontics, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan.
Kido
Mizuho A
MA
Zhang
Jing-Qi
JQ
Yamaza
Takayoshi
T
Nakata
Shunsuke
S
Nakasima
Akihiko
A
Tanaka
Teruo
T
D000818:Animals; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D007150:Immunohistochemistry; D007211:Indoles; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050916:TRPV Cation Channels / Q000378:metabolism*; D013704:Temporomandibular Joint / Q000294:innervation*
D005456:Fluorescent Dyes; D007211:Indoles; D012333:RNA, Messenger; D050916:TRPV Cation Channels; C007293:DAPI