Effect of hyperbaric oxygen on HIF-1α expression in rat experimental periodontitis with psychological stress

Objective: This study is to investigate the effect of hyperbaric oxygen (HBO) on HIF-1α expression in rat experimental periodontitis with psychological stress. Methods: One hundred and twenty male special pathogenfree Wistar rats were randomly divided into four groups: normal control group, experimental periodontitis group, psychological stress stimulation group, and periodontitis model with stress stimulation group. Six rats from each experiment group were randomly chosen for HBO treatment for 2 weeks. Gingival index (GI) and periodontal attachment loss (AL) were measured before sacrifice. The expression of HIF-1α was detected by immunohistochemistry. Results: The sites of gingival attachment were normal in control group and psychological stress stimulation group. The tissue damage was more severe, and the levels of GI, AL, and HIF-1α expression scores in periodontal tissues were higher in periodontitis with stress stimulation group than that in experimental periodontitis group, while they were comparable in control group and psychological stress stimulation group. After HBO treatment, the levels of GI, AL, and HIF-1α expression scores were significantly lower than that of the untreated groups (P<0.05). Conclusion: The results demonstrated that the severity of periodontitis was related to psychological stress and HBO could be effective on periodontitis and periodontitis with psychological stress in rat models.