Settareh Khashaee - Neurophysiology Research Center, Physiology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Homa Manaheji - Neurophysiology Research Center, Physiology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Nazanin Nikzad - International Branch of Shahid Beheshti University of Medical Sciences, Tehran, Iran
Jalal Zaringhalam - Neurophysiology Research Center, Physiology Department, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background: 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 weattempted to investigate the role of prescription of calcium to reduceinflammatory edema and serum TNF-α level during different stages of arthriticinflammation induced by Complete Freund Adjuvant (CFA) injection in maleWistar rats.Materials and 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 hind paw of animals on day zero in experimental groups. Various doses of calcium were prepared and injected within 21 days of the study. Hyperalgesia and paw volume changes were assessed by radiant heat and plethysmometer over several days, respectively. Serum levels of TNF-α were checked by ELISA standard kit for each 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 in comparison to AA and AA+ Vehicle groups on days 7, 14, and 21 of study.Conclusion: Findings of this study showed that 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.

Calcium, TNF-α, Edema, Complete Freund s adjuvant, Hyperalgesia, Inflammation