Trigeminal purinergic P2X4 receptor involved in experimental occlusal interference-induced hyperalgesia in rat masseter muscle.
- VernacularTitle:三叉神经节嘌呤能P2X4受体参与(牙合)干扰致大鼠咬肌痛觉过敏的研究
- Author:
Xiaoxiang XU
1
;
Ye CAO
1
;
Tingting DING
1
;
Kaiyuan FU
2
;
Qiufei XIE
1
Author Information
- Publication Type:Journal Article
- MeSH: Adenosine Triphosphate; administration & dosage; analogs & derivatives; pharmacology; Animals; Dental Occlusion; Hyperalgesia; etiology; Male; Masseter Muscle; drug effects; Masticatory Muscles; Purinergic P2X Receptor Antagonists; administration & dosage; pharmacology; RNA, Messenger; metabolism; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, Purinergic P2X4; genetics; metabolism; Time Factors; Trigeminal Ganglion; metabolism
- From: Chinese Journal of Stomatology 2016;51(3):176-181
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore the expression of purinergic p2X4 receptor (P2X4R) in trigeminal ganglion of rats after occlusal interference. Investigation of peripheral receptor mechanism of occlusal interference-induced masticatory muscle pain will aid the development of drug intervention against this condition.
METHODSExperimental occlusal interference was established by application of 0.4 mm metal crown to the upper right first molar of male Sprague-Dawley rats. Real-time PCR assay was used to investigate P2X4R mRNA level in trigeminal ganglion in rats with occlusal interference for 3, 7, 10 and 14 days and in control rats without occlusal interference (n=5 in each). Retrograde labelling combining immunofluorescence was performed to evaluate the percentage of P2X4R-positive cells in masseter afferent neurons (n=5 in each group). Graded concentrations of P2XR antagonist TNP-ATP (0.1, 10, 125, 250, 500 μmol/L) or saline (n=5 in each group) was administrated in right masseter and the mechanical sensitivity of bilateral masseters was measured before occlusal interference application, before the injection, and 30 min as well as 60 min after the injection.
RESULTSCompared with control rats (P2X4R mRNA: right side: 1.00±0.26, left side: 0.94± 0.21; percentage of P2X4R-positive masseter afferents: right side: [64.3±6.3]%, left side: [67.7±5.8]%), the level of P2X4R mRNA in bilateral trigeminal ganglia (right side: 5.98±3.56; left side: 5.06±2.88) of rats with occlusal interference for 7 days up-regulated (P<0.01) and the percentage of P2X4R-positive masseter afferent neurons(right side: [81.7±1.5]%; left side: [82.9±2.3]%) increased (P<0.05). Local administration of 10, 125, 250, 500 μmol/L TNP-ATP increased the mechanical withdrawal threshold in masseter 30 min after injection, compared with those before injection (P<0.05).
CONCLUSIONSIncreased expression of trigeminal P2X4R involves in the development of occlusal interference-induced masseter hyperalgesia.