Figure 4.

Effects of experimental periodontitis on the inflammatory status of the gingival tissues. Immunohistochemical expression of IL-6, IL-1β, and TNF-α in the interdental gingiva and periodontal ligament (a). Immunohistochemical analysis of IL-6, IL-1β, and TNF-α (b). Means and standard deviations of the number of positive cells. Results represent the means ± SEM of four samples. The expression of inflammation-related genes in rat gingival tissues (c). Total RNA was extracted from the gingival tissue around the first molars, and the mRNA levels of TNF-α, IL-6, IL-1β, iNOS, COX2, MMP-1, MMP-3, and MMP-13 were determined by qRT-PCR. Results represent the means ± SEM of three samples. Statistical analysis was performed with one-way ANOVA. ns, no significance. * p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001.