[Effects of interleukin-18 and hypoxia-inducible factor-1α in serum and gingival tissues of rat model with periodontitis exposed to chronic intermittent hypoxia]

Abstract

Objectve: This study evaluates the expression of interleukin-18 (IL-18) and hypoxia-inducible factor (HIF)-lα in rat periodontitis model exposed to normoxia and chronic intermittent hypoxia (CIH) environments. The possible correlation between periodontitis and obstructive sleep apnea-hypopnea syndrome (OSAHS) was also investigated. Methods: Thirty-two Sprague-Dawley (SD) rats were randomly assigned into four groups: normoxia control, normoxia periodontitis, hypoxia control, and hypoxia periodontitis groups. The periodontitis models were established by ligating the bilateral maxillary second molars and employing high-carbohydrate diets. Rats in hypoxia control and hypoxia periodontitis groups were exposed to CIH treatment mimicking a moderately severe OSAHS condition. All animals were sacrificed after eight weeks, and the clinical periodontal indexes were detected. The levels of IL-18 and HIF-1α in serum and gingival tissues were determined using enzyme-linked immunosorbent assay (ELISA). The correlation between attachment loss (AL) and the levels of IL-18 and HIF-lα in hypoxia periodontitis group was evaluated.

Results: The levels of IL-18 and HIF-lα in hypoxia periodontitis group were significantly higher than that in normoxia periodontitis and hypoxia control groups (P<0.05). Furthermore, the levels of IL-18 and HIF-lα in serum (r-0.792, r=0.753, P<0.05) and gingival tissues (r-0.817, r=0.779, P<0.05) were positively correlated with AL.

Conclusion: CIH could aggravate the destruction of periodontal tissues, which is correlated with IL-18 and HIF-lα levels.

图 1. 4组大鼠牙槽骨的X线片

Fig 1 X-ray images of alveolar bone in four groups of rats A：常氧对照组；B：常氧牙周炎组；C：低氧对照组；D：低氧牙周炎组。

图 2. 4组大鼠上颌第二磨牙根分叉区组织学观察 HE × 40

Fig 2 Histological observation of the furcation of maxillary second molars in four groups of rats HE × 40 A：常氧对照组；B：常氧牙周炎组；C：低氧对照组；D：低氧牙周炎组。