模拟高原缺氧对慢性牙周炎大鼠牙龈组织中基质金属蛋白酶-2活性的影响

Effect of simulated altitude hypoxia on the activity of matrix metalloproteinase-2 in gingival tissue of chronic periodontitis rat model

目的观察常氧与缺氧条件下慢性牙周炎大鼠牙龈组织中基质金属蛋白酶-2(MMP-2)的活性变化,探讨MMP-2在高原牙周病发生发展中的作用。方法健康成年SD大鼠32只,随机分为正常对照组(N组)、常氧牙周炎组(P1组)、缺氧对照组(H组)、缺氧牙周炎组(P2组),每组8只。P1、P2组分别在常氧与模拟海拔5000m缺氧条件下建立常氧与缺氧牙周炎模型,N、H组作为对照。采用明胶酶活性分析方法检测各组大鼠牙龈组织中活化形式MMP-2的表达水平。结果N、P1、H、P2组牙龈组织中活化形式MMP-2灰度值分别为13.72±6.22、37.23±4.40、14.45±6.51、45.44±4.79,其中N组与N组(P<0.05)、P2组与P1组(P<0.05)、P1组与N组(P<0.01)、P2组与H组(P<0.01)比较差异均有统计学意义,以P2组牙龈组织中活化形式MMP-2灰度值最高。结论模拟高原缺氧环境可提高慢性牙周炎大鼠牙龈组织中活化形式MMP-2含量,进而促进牙周病的发生、发展。

Objective To observe the changes in activity of matrix metalloproteinase-2 （MMP-2） in gingival tissue of a chronic periodontitis rat model in normoxia and hypoxia condition, and explore the role of MMP-2 in the development of high altitude periodontal diseases. Methods Thirty-two adult SD rats were randomly divided into 4 groups （8 each）： normal control group （N group）, normoxia periodontitis group （P1 group）, hypoxia control group （H group） and hypoxia periodontitis group （P2 group）. The chronic periodontitis rat model was reproduced in P1 and P2 group, and the rats were kept either in normoxia condition or hypoxia condition in a hypobaric chamber in which a condition simulating 5000 meter high altitude was established. Rats without periodontitis in N and H group were treated with the same conditions as control. The activation of MMP-2 in gingival tissue of rats in each group was measured by gelatin zymographic analysis. Results The grey values of activated MMP-2 in N, P1, H and P2 group were 13.72±6.22, 37.23±4.40, 14.45±6.51 and 45.44±4.79, respectively. The value was higher in H group than in N group, in P2 group than in P1 group （P0.05）, in P1 group than in N group, and in P2 group than in H group （P0.01）. The grey value of activated MMP-2 in gingival tissue in P2 group was the highest among the 4 groups. Conclusion Simulated high altitude hypoxia can increase the activated MMP-2 level in gingival tissue of rat with chronic periodontitis, and thus promoting the development of periodontal diseases.