慢性睡眠剥夺对颞下颌关节微结构的影响

目的:研究慢性睡眠障碍对大鼠颞下颌关节微结构的影响。方法:采用改良多平台法(MMPM)建立睡眠剥夺模型,将90只Wistar大鼠随机分为3组(n=30),分别为小平台组、网格组和对照组。小平台组和网格组大鼠接受每天18 h的睡眠剥夺和6 h间歇期(10:00—16:00),间歇期大鼠正常笼养。实验第7、14和21天时分别行动物行为学观察、旷场试验和动物血浆检测,并通过HE染色和扫描电镜观察颞下颌关节微结构的变化。结果:与对照组和网格组相比,小平台组大鼠血清促肾上腺激素(ACTH)和皮质醇(CORT)水平均增高(P<0.05),髁突软骨HE染色显示软骨细胞层次及厚度改变;扫描电镜结果显示关节盘表面纤维排列松散。结论:慢性睡眠障碍可能导致颞下颌关节微结构发生病理性改变。

Effects of Chronic Sleep Deprivation on the Ultrastructure of Temporomandibular Joint

Objective:To investigate the effects of chronic sleep deprivation (Wistar) on the ultrastructure of temporomandibular joint (TMJ).Methods:The Sleep deprivation (SD) was conducted according to modified multiple platform method (MMPM). The platforms were the support points for the animals when the tank filled with water, and rats which were placed on narrow platforms would fall into the water and wake up when their muscle relaxed (fall into sleep) during sleep deprived period; while rats that stayed on wide platforms were allowed to lie down without falling into water and could sleep anytime. Food and water were available to the animals at all times during the experiment. 90 Wistar rats were divided into three groups (N=30), narrow platform group, grid group and control group. The sleep deprivation protocol was accomplished by sleep depriving with rats for 18 h every day for 3 weeks, and the rats were allowed to sleep for 6h (from 10:00 to 16:00) in cages. The stress level of animals was estimated by the change of behavior, elevated plus-maze (EPM) and hormal assays, while the histomorphology and microstructure of rat condyles were observed by hematoxylineosin (HE) staining and scanning electron microscopy (SEM) at the 1, 2, and 3 week during the experiment, respectively.Results:Both plasma adrenocorticotropic hormone (ACTH), corticosterone (CORT) were higher in the narrow platform group than that of grid group and control group (P<0.05). HE staining and histomorphometric data analysis showed decreased thicknesses of the central and posterior condylar cartilages in stressed rats at the 3 weeks in the narrow platform group. However, the collagen fibers fissures could be observed on the disc of TMJ under the scanning electron microscope.Conclusion:Sleep deprivation could lead to pathologic changes of the condyles of stressed rats, suggesting a potential link between sleep disturbance and the pathogenesis or progression of TMD.