Tariba Knežević Petra, Vukman Robert, Uhač Mia, Illeš Davor, Kovačević Pavičić Daniela, Simonić-Kocijan Sunčana
Department of Prosthodontics, Faculty of Dental Medicine, University of Rijeka, Rijeka, Croatia.
Department of Prosthodontics, Clinic of Dental Medicine, Clinical Hospital Center Rijeka, Rijeka, Croatia.
J Pain Res. 2020 Jun 3;13:1323-1333. doi: 10.2147/JPR.S239831. eCollection 2020.
PY receptors (PYRs) are among the various receptors that play an important role in nociception. The goal of this research was to investigate possible PYR expression changes in the trigeminal ganglion (TRG) in bilateral masseter muscle (MM) hypersensitivity following unilateral MM inflammation. The impact of unilateral intramasseteric administration of PYR antagonist on bilateral MM hypersensitivity was also explored.
Bilateral MM hypersensitivity was provoked by unilateral intramasseteric injection of complete Freund's adjuvant (CFA). The head withdrawal threshold (HWT) was assessed bilaterally 4 days later. Bilateral TRG and MM isolation were followed, and quantitative real-time polymerase chain reaction (qRT-PCR) and histopathological analysis were carried out on these tissues, respectively. The involvement of PYRs in nocifensive behavior was evaluated by administering two doses of PYR antagonist AR-C118925 (0.2 or 1 mg/100 μL) in inflamed MM 4 days post-CFA administration. Bilateral HWT was assessed at different time points following antagonist injection.
qRT-PCR analysis demonstrated PYR up-regulation in TRG ipsilateral to the site of CFA administration. Compared to the controls, both doses of AR-C118925 injected ipsilateral to the TRG increased the bilateral HWT at 30, 60, 90, and 120 minutes after antagonist administration.
The findings suggest that PYRs may affect MM inflammatory hypersensitivity owing to its up-regulation in the TRG in MM inflammatory pain states.
PY受体（PYRs）是在伤害感受中起重要作用的多种受体之一。本研究的目的是调查单侧咬肌（MM）炎症后双侧咬肌超敏反应时三叉神经节（TRG）中PYR表达的可能变化。还探讨了单侧咬肌内注射PYR拮抗剂对双侧咬肌超敏反应的影响。
通过单侧咬肌内注射完全弗氏佐剂（CFA）诱发双侧咬肌超敏反应。4天后双侧评估头部退缩阈值（HWT）。随后分离双侧TRG和MM，并分别对这些组织进行定量实时聚合酶链反应（qRT-PCR）和组织病理学分析。在给予CFA后4天，通过在发炎的咬肌中注射两剂PYR拮抗剂AR-C118925（0.2或1mg/100μL）来评估PYRs在伤害防御行为中的作用。在注射拮抗剂后的不同时间点评估双侧HWT。
qRT-PCR分析显示，在CFA给药部位同侧的TRG中PYR上调。与对照组相比，在TRG同侧注射的两剂AR-C118925均在拮抗剂给药后30、60、90和120分钟时提高了双侧HWT。
研究结果表明，在咬肌炎症疼痛状态下，TRG中PYRs上调可能会影响咬肌的炎症性超敏反应。
