慢性不可预知性应激对大鼠实验性牙周炎预后的影响

目的:探讨慢性不可预知性复合心理应激对大鼠实验性牙周炎模型牙周组织愈合的影响。方法:雄性SD大鼠128只,随机抽取32只作为正常对照组。其余96只大鼠用丝线结扎右上颌第二磨牙颈部,4周后,采用龈沟出血指数和牙周探诊深度验证牙周炎模型。同时将大鼠结扎丝线去除,随机分为牙周炎对照组、牙周炎+应激组、牙周炎+应激+应激对抗药物组,每组32只。实验第5周起,应激组和药物组大鼠每日给予慢性不可预知性应激,同时药物组每日按5 mg/kg腹腔注射氟西汀。于实验第4、5、6、8周进行大鼠体质量测量、行为学测试、血清学检测;采用组织学观察牙周组织炎症反应、牙槽骨丧失、附着丧失以及破骨细胞计数。结果:心理应激大鼠出现体质量增长减慢、行为异常、血清皮质酮与促肾上腺皮质激素浓度升高(P<0.05),心理应激影响下大鼠牙周炎的愈合进程减慢,炎细胞浸润面积、牙槽骨吸收量与破骨细胞计数在实验第6周和8周、附着丧失在第8周高于对照组(P<0.05)。抗应激药物可逆转心理应激对牙周炎愈合过程的影响,该组炎细胞浸润面积与牙槽骨吸收在第6周和8周、破骨细胞计数在第8周明显低于应激组(P<0.05)。结论:慢性不可预知性心理应激能影响牙周组织的愈合,影响牙周炎的预后。而药物对抗应激能够减轻这种影响。

Effect of chronic unpredictable stress on the healing process of experimental periodontitis in rats

AIM: To investigate the effect of chronic unpredictable stress on the healing process of experimental periodontitis in rats.METHODS: Thirty-two out of one hundred and twenty-eight male Sprague-Dawley rats were randomly selected as control group;the rest of the rats were operated by placing a silk ligature around cervix of the right second maxillary molar to induce experimental periodontitis.After four weeks,sulcus bleeding index(SBI) and periodontal probe depth(PD) were used to testify the animal model.Then the ligature was removed and the rats were randomly divided into periodontitis group;periodontitis and stress group;periodontitis and stress+drug group.Chronic unpredictable stress was given to the rats in stress group and drug group everyday from week 5.Also,fluoxetine was given to drug group 5mg/Kg daily.The rats in every group were sacrificed at week 4,5,6,8.The body weight gained,behavior tests and serum tests were used to testify stressed condition.Histological examinations were used to evaluate the changes of periodontal tissues.RRSULTS: The stressed rats showed less body weight gained,affective-like behavioral changes and increased serum corticosterone(CORT) and adrenocorticotropic hormone(ACTH)(P<0.05).The surface of inflammatory infiltrate,alveolar bone loss and osteoclast numbers at week 6 and 8,and the attachment loss at week 8 of the stress group were significantly higher than those of periodontitis group(P<0.05).The surface of inflammatory infiltrate and alveolar bone loss at week 6 and 8,and the osteoclast numbers at week 8 of the drug group were significantly lower than those of the stress group(P<0.05).CONCLUSION: Chronic unpredictable stress can result in delayed healing of the periodontal tissue in periodontitis while fluoxetine might antagonize the stress and alleviate its negative effect.