title: Oxidative damage and HSP70 expression in masseter muscle induced by psychological stress in rats.
abstract: Psychological stressors are generally associated with masseter muscle dysfunction and disorders in emotional response. In addition, oxidative states and HSP70 expression, which are involved in the physical and pathological changes of the masseter muscle, could be altered in the stressed tissues and organs. However, the link between psychological stress and the redox homeostasis or the expression of HSP70 in masseter muscles in rats has not been examined. Therefore, we used a communication box paradigm to induce psychological stress in rats. The successful establishment of the animal model was evidenced by an increase in plasma corticosterone and adrenocorticotropic hormone (ACTH). Meanwhile, the stressed rats showed a decrease in the number of entries on open arms, percentage of time spent in open arms, and distance moved in the elevated plus-maze test. The stressed rats also displayed a decrease in the time spent in the center zone, active velocity, and the distance moved in the open-field test. These results demonstrate affective-like behavioral changes in the stressed rats. Moreover, compared with the control rats, a decrease in SOD, GSH-Px and catalase activities and an increase in MDA content were observed in the masseter muscles in stressed rats after 3 weeks and 5 weeks, and the HSP70 expression was elevated in muscles in the rats exposed to stress for 5 weeks. These results indicate that psychological stress induces oxidative damage and up-regulates the expression of HSP70 in masseter muscles in rats, which are associated with behavior resembling anxiety.
authors.affiliation: Department of General Dentistry & Emergency, School of Stomatology, Fourth Military Medical University, Xi'an 710032, Shaanxi, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Chen
authors.forename: Ying-Jie
authors.initials: YJ
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Huang
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
mesh_terms: D000311:Adrenal Glands / Q000473:pathology; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000209:etiology; D001835:Body Weight; D002374:Catalase / Q000378:metabolism; D003345:Corticosterone / Q000097:blood; D004195:Disease Models, Animal; D004597:Electroshock / Q000009:adverse effects; D005106:Exploratory Behavior / Q000502:physiology; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008406:Masseter Muscle / Q000378:metabolism*; D018782:Maze Learning / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013315:Stress, Psychological / Q000097:blood / Q000150:complications / Q000209:etiology / Q000473:pathology*; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D008315:Malondialdehyde; D000324:Adrenocorticotropic Hormone; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D003345:Corticosterone