Dynamics of inflammatory cytokines in rats with spontaneous periodontal disease

Abstract

Inflammatory cytokines, interleukin-1 β (IL-1 β), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α), are considered to be involved in the expression and activation cascade of matrix metalloproteinases (MMPs). Increased expression of these inflammatory cytokines in gingival tissue and gingival sulcus exudates in periodontal disease patients has been confirmed. Cytokines are also related to the development and progression of inflammation, and are classified into those promoting and inhibiting alveolar bone resorption. In this study, we measured the plasma levels of IL-1 β, IL-6 and TNF-α in rats with spontaneous periodontal disease (ODUS/Odu), an animal model of periodontal disease developed by our laboratory, which has reached the 104th generation as an inbred strain. We used an enzyme-linked immunosorbent assay (ELISA) kit to measure the plasma cytokine levels at the initiation of the experiment and at 1, 3, 6, 9, and 12 months, in ODUS/Odu and in plaque-resistant rats (Res). The IL-1 β and TNF-α levels were significantly greater in ODUS/Odu than in Res at all experimental periods (p<0.001). The IL-6 level was significantly greater in ODUS/Odu than in Res at 6, 9, and 12 months (p<0.05). These findings were similar to those in patients with periodontal disease, suggesting that ODUS/Odu serve as a useful animal model.