Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA.
Neurosci Lett. 2011 Apr 15;493(3):72-5. doi: 10.1016/j.neulet.2011.01.027. Epub 2011 Jan 15.
Osteoarthritis (OA) is a chronic pain condition characterized by pain during joint use as well as pain at rest (i.e., ongoing pain). Although injection of monosodium iodoacetate (MIA) into the intra-articular space of the rodent knee is a well established model of OA pain that is characterized by changes in weight bearing and hypersensitivity to tactile and thermal stimuli, it is not known if this procedure elicits ongoing pain. Further, the time-course and possible underlying mechanisms of these components of pain remain poorly understood. In these studies, we demonstrated the presence of ongoing pain in addition to changes in weight bearing and evoked hypersensitivity. Twenty-eight days following MIA injection, spinal clonidine blocked changes in weight bearing and thermal hypersensitivity and produced place preference indicating that MIA induces ongoing and evoked pain. These findings demonstrate the presence of ongoing pain in this model that is present at a late-time point after MIA allowing for mechanistic investigation.
骨关节炎（OA）是一种慢性疼痛病症，其特征是关节使用时疼痛以及休息时疼痛（即持续疼痛）。虽然向啮齿动物膝关节关节腔内注射单碘乙酸（MIA）是一种成熟的 OA 疼痛模型，其特征是负重改变和对触觉和热刺激的超敏反应，但尚不清楚该程序是否会引起持续疼痛。此外，这些疼痛成分的时程和潜在机制仍知之甚少。在这些研究中，我们除了观察到负重改变和诱发的超敏反应外，还证明了存在持续疼痛。在 MIA 注射后 28 天，脊髓可乐定阻断了负重改变和热超敏反应，并产生了位置偏好，表明 MIA 引起了持续和诱发的疼痛。这些发现表明，在 MIA 后晚期，该模型存在持续疼痛，为机制研究提供了可能。
