Objective To evaluate the effects of carbon monoxide releasing molecule-2 (CORM-2) on experimental perio-dontitis inrats.Methods Forty-two Wistarratswere divided into three groups.Ratsin the normal group (NL group)did not undergo any procedure, whereas the other rats were ligatured and treated with saline solution (NaCl 0.9%) (LO group) or treated with CORM-2 (10 mg• kg-1 per day) (CO group). A 3-0 silk suture was placed around the mandibular first molars. Rats were sacrificed after 3, 7, and 10 d. Blood samples were collected from all animals for tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) analysis. Changes in alveolar bone levels were measured clinically, and periodontal tissues were histopathologically examinedto assess the infiltration of inflammatory cells.Results Ligature placement increased alveolar bone loss and inflammatory cell infiltration in periodontal tissue. Alveolar bone loss in CO group was significantly higher than that in NL group, but was lower than that in LO group (PConclusion Systemic administration of CORM-2 reduced periodontal inflam-mation andalveolar bone loss in experimental periodontitis in rats.
