Weight bearing as a measure of disease progression and efficacy of anti-inflammatory compounds in a model of monosodium iodoacetate-induced osteoarthritis

AbstractObjective: To describe an in vivo model in the rat in which change in weight distribution is used as a measure of disease progression and efficacy of acetaminophen and two nonsteroidal anti-inflammatory drugs (NSAIDs) in a model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA).Methods: Intra-articular injections of MIA and saline were administered to male Wistar rats (175–200g) into the right and left knee joints, respectively. Changes in hind paw weight distribution between the right (osteoarthritic) and left (contralateral control) limbs were utilized as an index of joint discomfort. Acetaminophen and two archetypal, orally administered NSAIDs, naproxen and rofecoxib, were examined for their ability to decrease MIA-induced change in weight distribution.Results: A concentration-dependent increase in change in hind paw weight distribution was noted after intra-articular injection of MIA. Both naproxen and rofecoxib demonstrated the capacity to significantly (P