dynorphin-(1-32) and Osteoarthritis

Animal models are useful to evaluate pharmacological therapies to alleviate joint pain. The present study characterized central neuropeptides modulation in the monoiodoacetate (MIA) rat model. Animals receiving a single 3mg MIA injection were euthanized at 3, 7, 14, 21 and 28 days post injection. Spinal cords were analyzed by liquid chromatography ion trap mass spectrometry. Up-regulations of the calcitonin gene-related peptide and substance P were observed starting on days 7 and 28 respectively, whereas big dynorphin(₁₋₃₂) content decreased significantly on day 14 in comparison to control animals (P<0.05). Preclinical drug evaluations using this model should be conducted between 7 and 21 days post injection when the lesions resemble most to human osteoarthritis.

Topics: Animals; Calcitonin Gene-Related Peptide; Chromatography, Liquid; Disease Models, Animal; Dynorphins; Enzyme Inhibitors; Humans; Iodoacetic Acid; Knee Joint; Male; Neuropeptides; Osteoarthritis; Pain; Rats; Rats, Sprague-Dawley; Spinal Cord; Substance P; Tandem Mass Spectrometry; Time Factors