Journal of pharmacological and toxicological methods
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J Pharmacol Toxicol Methods · Jan 2012
Establishment of a novel objective and quantitative method to assess pain-related behavior in monosodium iodoacetate-induced osteoarthritis in rat knee.
Pain in osteoarthritis (OA) patients can be present at rest but typically worsens with movement of the affected joint. However, useful assessment methods of movement-induced pain in animal models are limited. Here, we describe the reduction of spontaneous activity in a rat model of OA as an objective and quantifiable behavioral pain that can predict the analgesic activity of a variety of agents following single-dose administration. ⋯ This study indicates that unlike standard measures of analgesia such as alteration in thermal or mechanical sensitivity, measurement of spontaneous activity is a validated method for measuring the effects of analgesics in rats with OA knee joints. Moreover, the animals require no habituation, and thus behavioral observation subjectivity is eliminated.