Abstract:

Objective To observe the activity of superoxide dismutase（SOD） in rabbit periodontitis model in normoxia and hypoxia environment, and to research the pathogenesis of periodontal diseases at high altitude. Methods Fourty male rabbits were randomly divided into four groups: Normoxia control group, normoxia periodontitis group（periodontitis models）, hypoxia control group, hypoxia periodontitis group（periodontitis models）. The periodontitis models were established by ligating the two central incisors of mandible and raised by periodontitis diets. The weights of four groups were dynamically observed. After eight weeks, the clinical periodontal indexes and the activity of total-SOD（TSOD） in blood serum and gingival tissues in all groups were detected. Results The activity of T-SOD of hypoxia periodontitis group was significantly lower than normoxia periodontitis group and hypoxia control group（P＜0.05）, the  weights and clinical periodontal indexes were also dramatically different（P＜0.01）. The activity of SOD in serum was positively correlated with the gingival tissues（r=0.846, P<0.01）, and they both negatively correlated with AL（r=-0.980, -0.804, P<0.01）. Conclusion The growth state of the body and the balance of bioconversion were affected in hypoxia environment when exposed at high altitude. The activity of SOD in total body and local tissues were decreased, thus the superoxide free radicals were accumulated in the body, especially in local periodontal tissues. Therefore it can accelerate and aggravate the destruction of periodontal tissues.

Key words: high altitude, hypoxia, periodontitis, superoxide dismutase