anti-hyperalgesic and anti-inflammatory effects of long termcalcium administrationduring adjuvant-induced arthritisin rats

introduction: inflammation and edema symptoms are physiological response to triggers that can be induced by different mediators such as cytokines. rheumatoid arthritis is the most common form of arthritis which is characterized by chronic inflammation of the synovial membrane, severe and debilitating pain and progressive cartilage injury. it is clear that cytokines are involved in different stages of inflammation by inducing pro-inflammatory effects; tnf-α as a cytokine involved in the pathogenesis of rheumatoid arthritis . in this study we attempted to investigate the role of prescription of calcium to reduce inflammatory edema and serum tnf-α level during different stages of arthritic inflammation induced by complete freund adjuvant (cfa) injection in male wistar rats. methods: in this applicable-fundamental study, we used male wistar rats and adjuvant arthritis was created by once subcutaneous injection of cfa in the right hindpaw of animals on day zero in experimental groups. various doses of calcium were prepared and injected within 21 days of study. hyperalgesia and paw volume changes wereassessed byradiant heat andplethysmometer over several days, respectively. the serum levels of tnf-α were studied by elisa standard kit of rat during various phases and were measured according to the kit. results : the results indicated dose related effects of long term calcium administration on edema, hyperalgesia and serum tnf-α level reduction. daily treatment with effective dose of calcium (5 mg/kg) in aa+ ca group significantly decreased paw edema, hyperalgesia and serum tnf-α level incomparison to aa and aa+ vehicle groups on days 7, 14 and 21 of study. conclusions : findings of this study showed;long term administration of calcium in the proper dosage can act as an anti-inflammatory agent and pain modulator during adjuvant-induced arthritis and a part of those effects may conducted by decreasing of serum tnf-α level.