Figure 3. Gingivomucosal section from non-ligature-treated rats (a) demonstrating no tissue damage. Inflammatory cell infiltration and edema were observed in gingivomucosal sections from ligature-treated rats (c,c1). Significantly less edema and inflammatory cell infiltration was observed in gingivomucosal sections from ligature-treated rats treated with rosiglitazone (10 mg/kg i.p., daily for 8 days) (b). We quantitatively assessed the total number of infiltrating leukocytes (e.g., neutrophils and mononuclear cells) in gingivomucosal tissue by counting the number of polymorphonuclear cells in 20 high-power fields (d). The Fig. is representative of at least 3 experiments performed on different experimental days. The tissue sections, oriented longitudinally from the crown, were stained with trichrome stain. Data represent the mean ± SEM for 20 counts obtained from the gingivomucosal tissue of each treatment group. *P < 0.01 vs. non-ligated. °P < 0.01 vs. ligated.