Melatonin Plays a Role as a Mediator of Nocturnal Pain in Patients with Shoulder Disorders

作者:Ha Eunyoung*; Lho Yun Mee; Seo Hyuk Jun; Cho Chul Hyun
来源:Journal of Bone and Joint Surgery-American Volume, 2014, 96A(13): e108.
DOI:10.2106/JBJS.M.01011

摘要

Background: Nocturnal pain is commonly observed in patients with shoulder disorders such as a rotator cuff tear or frozen shoulder. This study was conducted to explore the possibility that melatonin plays a role as a mediator of nocturnal pain in patients with a rotator cuff tear or frozen shoulder. Methods: Subacromial bursa and joint capsule samples were collected from sixty-three patients: twenty-one patients with a rotator cuff tear, twenty-two with frozen shoulder, and twenty with shoulder instability (control group). The expression of melatonin receptor 1A (MTNR1A) and 1B (MTNR1B) and of acid-sensing ion channel 3 (ASIC3) in the subacromial bursa and the joint capsule were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. The protein level of ASIC3 was measured by immunoblot analysis. To determine the effect of melatonin as a pain mediator, an in vitro study with use of primary cultured fibroblast-like synoviocytes was performed by semiquantitative RT-PCR analysis, immunoblot analysis, and enzyme-linked immunosorbent assay (ELISA). Results: MTNR1A, MTNR1B, and ASIC3 expression was significantly increased in both the rotator cuff tear and frozen shoulder groups compared with the control group of patients with shoulder instability. Interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) significantly stimulated the expression of MTNR1A and MTNR1B in primary cultured fibroblast-like synoviocytes treated with proinflammatory cytokines. Melatonin treatment at a physiological concentration (10 nM) induced ASIC3 expression and IL-6 production. Treatment with luzindole, amelatonin-receptor antagonist, reversed melatonin-stimulated ASIC3 expression and IL-6 production. Conclusions: Our study suggests that melatonin may play a role as a mediator of nocturnal pain with a rotator cuff tear or frozen shoulder, and this effect may be mediated via melatonin receptors.

  • 出版日期2014-7-2