1. Academic Validation
  2. Periodontal CGRP contributes to orofacial pain following experimental tooth movement in rats

Periodontal CGRP contributes to orofacial pain following experimental tooth movement in rats

  • Neuropeptides. 2015 Aug;52:31-7. doi: 10.1016/j.npep.2015.06.006.
Hu Long 1 Lina Liao 1 Meiya Gao 1 Wenqiang Ma 2 Yang Zhou 1 Fan Jian 1 Yan Wang 1 Wenli Lai 3
Affiliations

Affiliations

  • 1 State Key Laboratory of Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
  • 2 West China School of Stomatology, Sichuan University, Chengdu 610041, China.
  • 3 State Key Laboratory of Oral Diseases, Department of Orthodontics, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China. Electronic address: wenlilai@scu.edu.cn.
Abstract

Calcitonin-related gene peptide (CGRP) plays an important role in orofacial inflammatory pain. The aim of this study was to determine whether periodontal CGRP contributes to orofacial pain induced by experimental tooth movement in rats. Male Sprague-Dawley rats were used in this study. Closed coil springs were used to deliver forces. Rats were euthanized on 0d, 1d, 3d, 5d, 7d, and 14d following experimental tooth movement. Then, alveolar bones were obtained for immunostaining of periodontal tissues against CGRP. Two hours prior to euthanasia on each day, orofacial pain levels were assessed through rat grimace scale. CGRP and olcegepant (CGRP Receptor Antagonist) were injected into periodontal tissues to verify the roles of periodontal CGRP in orofacial pain induced by experimental tooth movement. Periodontal CGRP expression levels and orofacial pain levels were elevated on 1d, 3d, 5d, and 7d following experimental tooth movement. The two indices were significantly correlated with each other and fitted into a dose-response model. Periodontal administration of CGRP could elevate periodontal CGRP expressions and exacerbate orofacial pain. Moreover, olcegepant administration could decrease periodontal CGRP expressions and alleviate orofacial pain. Therefore, periodontal CGRP plays an important role in pain transmission and modulation following experimental tooth movement. We suggest that it may participate in a positive feedback aiming to amplify orofacial pain signals.

Keywords

CGRP; Pain; Periodontal tissue; Tooth movement; Trigeminal ganglion.

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