慢性心理应激致大鼠咬肌及髁突超微结构损伤后自然恢复的研究  

Natural recovery of ultrastructure damage of the masseter muscle and temporomandibular joint condylar cartilage of rats after chronic unpredictable mild stress treatment

作　　者：刘晓波[1] 黄锦梅[1] 马媛媛[1] 张旻 陈永进[1] 

机构地区：[1]第四军医大学附属口腔医学院,陕西西安710032

出　　处：《牙体牙髓牙周病学杂志》2014年第2期83-89,共7页Chinese Journal of Conservative Dentistry

基　　金：国家自然科学基金资助项目(81100772)

摘　　要：目的:探讨心理应激对髁突和咬肌的影响程度及是否可逆。方法:取8周龄SPF级雄性SD大鼠42只,随机等分为空白对照组、应激后即刻组以及应激后恢复2、4、8、12周共6组(n=7),空白对照组大鼠不予刺激,其他5组大鼠采用慢性轻度不可预见性应激(chronic unpredictable mild stress,CUMS)的方法连续处理12周,建立大鼠抑郁模型;通过体质量、旷场实验、摄糖实验评估大鼠的抑郁程度,采用酶联免疫法(ELISA)检测各大鼠的血清皮质醇(CORT)含量,电镜观察各组大鼠髁突表面和咬肌的超微结构变化。结果:12周的慢性应激后大鼠的血清学、行为学和体质量均发生明显变化(P<0.05);大鼠血清CORT浓度、旷场实验及糖水偏爱度分别在去除应激后4、8、12周时恢复正常,但体质量仍然低于对照组(P<0.05);12周应激后大鼠髁突与咬肌均出现损伤,去除应激12周后,咬肌基本恢复,髁突表面逐渐恢复但不完全。结论:CUMS导致的大鼠抑郁样行为以及咬肌和髁突软骨的损伤变化在去除CUMS刺激后是可以自然恢复的。AIM： To observe the natural recovery of uhrastructure damage of the masseter muscle and tem- poromandibular joint（TMJ） condylar cartilage induced by chronic unpredictable mild stress（CUMS） in rats. METH- ODS ： 42 SD rats aged 8-weeks old were randomly divided to 6 groups （ n = 7）. The rats were treated by CUMS except those in control group. Afterl2-week-CUMS treatment the rats were assigned to 5 groups for depressive-like rat model confirmation （ immediately after CUMS） and recovery observation 2, 4, 8 and 12 weeks after CUMS. The sucrose pref- erence test and open-field test were performed and body weight was measured to assess the depression state. The serum corticosterone （CORT） level was measured by ELISA. The uhrastructure of master and condylar surface was observed by SEM and TEM respectively. RESULTS： The depressive-like behavior in stressed rats was confirmed by the evi- dences observed in open field test, sucrose preference test and elevated serum CORT level. The abnormal changes of the stressed rats were gradualy recovered 4-12 weeks after CUMS treatment. However, body weight of the stressed rats remained lighter than that of the controls（ P 〈 0.05 ）. The pathological changes of the uhrastructure of masseter muscle and TMJ condylar was confirmed by SEM and TEM after 12 weeks of CUMS. After removal of CUMS the pathological change of masseter muscle was fully and that of TMJ partly recovered in 12 weeks. CONCLUSION： The depressive- like state and uhrastructure of masseter and TMJ caused by CUMS are reversible after the removal of the stress factors.

关 键 词：慢性不可预见性轻度应激 抑郁 髁突软骨 咬肌 自然恢复 

分 类 号：R782.6[医药卫生—口腔医学]