ABSTRACT
Objective To investigate the possible mechanisms of the attribution of psychological stress to the temporomandibular joint disorder(TMD) ,through the evaluation of the animal model and detection of the proinflammatory cytokines in the TMJ.Methods The animal models of communication box were built to mimic the psychological stress.The concentration of the serum Cor and ACTH was detected in the control group, Psychological Stress group ( PS group), and diazepam ( anti-anxiety drug) group ( PS + DI group).The expression of the proinflammatory cytokines IL-1 and IL-6 in the rat TMJ in the different phases of psychologicalstress was detected by RT-PCR.Results The results of the serum concen- tration of Cor and ACTH showed that there was significant difference between the control group and the PS group(P＜0.01 ) ,while no significant difference between the control group and the PS + DI group(P＞0.05).The expressions of IL-1 and IL-6 were comapared in all group.The expressions of IL-1 in CON group were (0.453± 0.021 ) mg/L, (0.439 ± 0.028 ) mg/L and (0.454 ± 0.023 )mg/L.These values were markedly increased compared with those of the PS group(0.981 ±0.024)mg/L, (0.746±0.017)mg/L and (0.510 ±0.016)mg/L respectively, P＜0.01 ) ,but no significant differences compared with PS + DI group(0.549 ± 0.014 ) mg/L, ( 0.498 ± 0.014 ) mg/L and ( 0.444 ± 0.022 ) mg/L respectively, P ＞ 0.05).Similar changes were observed in expressions of IL-6.The expressions of IL-6 in the CON rats were (0.525 ±0.028)mg/L,(0.515 ±0.028)mg/L and (0.518 ±0.022)mg/L,respectively,while those of PS group were(0.820 ± 0.023 ) mg/L, (0.694 ± 0.019 ) mg/L and (0.579 ± 0.015 ) mg/L, respectively, which were significan- tly higher in the PS groups(P＜ 0.05 ).But there were no significant differences between CON group and PS + DI group( (0.599 ±0.015)mg/L, (0.541 ±0.015)mg/L, (0.487 ±0.008)mg/L respectively, P＞0.05).Conclusion The psychological stress can play important role in the formation of TMD.