ArticlePartial medial meniscectomy produces osteoarthritis pain-related behaviour in female C57BL/6 miceKnights, Chancie Bayera; Gentry, Clivea; Bevan, Stuarta,* Author Information aWolfson Centre for Age Related Disease, Guys Campus, Kings College London, London SE1 1UL, UK *Corresponding Author. Tel.: +44 (0) 20 7848 6141; fax: +44 (0) 20 7848 6165. E-mail: [email protected] Submitted March 22, 2011; revised September 8, 2011; accepted September 9, 2011. Pain: February 2012 - Volume 153 - Issue 2 - p 281-292 doi: 10.1016/j.pain.2011.09.007 Buy Metrics Abstract Summary Partial medial meniscectomy produces progressive degenerative joint disease and accompanying evoked pain behaviours in C57Bl/6 mice, providing a model for the study of osteoarthritic pain behaviours. Murine models of osteoarthritis (OA) provide a potentially powerful tool to elucidate mechanisms responsible for OA pain. However, few studies have examined pain behaviours in relevant OA models in mice. We have therefore characterized the time course and pharmacological sensitivities of pain-related behaviours in a model of OA in C57Bl/6 mice induced by partial medial meniscectomy. Progressive degenerative joint damage developed in a time-dependent manner and was first detected 4 weeks after surgery. Pain was assessed by monitoring weight bearing, mechanical hyperalgesia, cold allodynia, mechanical allodynia and vocalisation in response to knee compression for 12 weeks postsurgery. No significant weight-bearing deficits were observed during the course of the study. Significant mechanical allodynia was present in the ipsilateral hind limb from 9 weeks after surgery. Hind limb mechanical hyperalgesia and cold allodynia, and increased vocalisation in response to knee compression developed in the ipsilateral limb in 2 phases. An early phase of hypersensitivities lasted for up to 3 weeks and was reversed by treatment with a nonsteroidal anti-inflammatory drug (NSAID), diclofenac. Pain then resolved for several weeks, followed by a second phase of NSAID-insensitive pain after 7 weeks postsurgery. During this phase, all pain behaviours could be reversed by morphine. In contrast, other analgesic drugs (paracetamol, gabapentin, and tramadol) had selective effects on only 1 or 2 modalities. Pain levels fluctuated during the second phase, with transient periods of reduced pain. At these times, underlying hypersensitivities could be unmasked by administration of naloxone, indicating that reduced pain was due to endogenous opioids. © 2012 Lippincott Williams & Wilkins, Inc.
