Xu X X, Cao Y, Fu K Y, Xie Q F
Department of Prosthodontics & Center for Oral and Jaw Functional Diagnosis, Treatment and Research, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081,China.
Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081,China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2017 Feb 18;49(1):25-30.
To investigate the effect of occlusal interference on the energy metabolism of masticatory muscle by studying the changes of adenosine triphosphate (ATP), adenosine diphosphate (ADP), inosine monophosphate (IMP), phosphocreatine, creatine, lactate and pH level in masseter muscles of rats after occlusal interference.
Fifty male Sprague-Dawley rats were randomly assigned into experimental group (n=40) and control group (n=10). In experimental group, 0.4 mm thick metal crown was cemented to the upper right first molar of the rat, and maintained for 3, 7, 10, 14 d separately (n=10 for each time point). No occlusal interference was applied for control group. Bilateral masseter muscles of all the rats were acquired under general anesthesia. The samples of 5 rats in each group were fully homogenized with 0.4 mol/L perchlorate (10 mL/g). The homogenates were centrifuged, filtered and analyzed for ATP, ADP, IMP, phosphocreatine, creatine and lactate content by high performance liquid chromatography. The other samples in each group were mixed with homogenates containing 5 mmol/L sodium iodoacetate (10 mL/g), then homogenized and measured for pH value by pH meter in thermostatic water bathunder 37 degrees centigrade.
Compared with control group, ATP content in bilateral masseter of the rats increased 3 d after occlusal interference [right side:(5.36±0.13) μmol/g,left side:(5.77±0.25) μmol/g] (P<0.05), and back to normal on 7, 10 and 14 d. There was an increase in IMP [right side:(0.21±0.03) μmol/g,left side:(0.19±0.03) μmol/g]and creatine content [right side:(24.76±2.94) μmol/g,left side:(27.75±2.23) μmol/g]in bilateral masseter of the rats 7 d after occlusal interference (P<0.05) and no difference was detected on 3, 10, and 14. Phosphocreatine content in bilateral masseter started to decline 7 d after occlusal interference and maintained the low level on 10 and 14 d right side:(10.70±0.71) μmol/g, (11.57±0.52) μmol/g, (10.74±1.39) μmol/g, left side:(10.05±0.57) μmol/g, (10.75±1.12)μmol/g, (10.61±1.15) μmol/g. No change of ADP, lactate or pH level in bilateral muscles of the rats after occlusal interference was observed (P>0.05).
Occlusal interference influences the content of energy metabolites in masticatory muscle of rats, which may be related to the pathological process of masticatory muscles induced by occlusal interference, such as muscle pain, dysfunction and altered fiber architecture.
通过研究咬合干扰后大鼠咬肌中三磷酸腺苷（ATP）、二磷酸腺苷（ADP）、一磷酸肌苷（IMP）、磷酸肌酸、肌酸、乳酸及pH值的变化，探讨咬合干扰对咀嚼肌能量代谢的影响。
将50只雄性Sprague-Dawley大鼠随机分为实验组（n = 40）和对照组（n = 10）。实验组在大鼠右上第一磨牙粘结0.4 mm厚的金属冠，并分别维持3、7、10、14天（每个时间点n = 10）。对照组不施加咬合干扰。所有大鼠在全身麻醉下获取双侧咬肌。每组5只大鼠的样本用0.4 mol/L高氯酸盐（10 mL/g）充分匀浆。匀浆液经离心、过滤后，采用高效液相色谱法分析ATP、ADP、IMP、磷酸肌酸、肌酸和乳酸含量。每组的其他样本与含5 mmol/L碘乙酸钠的匀浆液（10 mL/g）混合，然后匀浆，并在37℃恒温水浴中用pH计测量pH值。
与对照组相比，咬合干扰后3天大鼠双侧咬肌ATP含量升高[右侧：(5.36±0.13) μmol/g，左侧：(5.77±0.25) μmol/g]（P<0.05），并在7、10和14天恢复正常。咬合干扰后7天大鼠双侧咬肌IMP[右侧：(0.21±0.03) μmol/g，左侧：(0.19±0.03) μmol/g]和肌酸含量[右侧：(24.76±2.94) μmol/g，左侧：(27.7±2.23) μmol/g]升高（P<0.05），在3、10和14天未检测到差异。咬合干扰后7天双侧咬肌磷酸肌酸含量开始下降，并在10和14天维持在低水平[右侧：(10.70±0.71) μmol/g，(11.57±0.52) μmol/g，(10.74±1.39) μmol/g，左侧：(10.05±0.57) μmol/g，(10.75±1.12)μmol/g，(10.61±1.15) μmol/g]（P<0.05）。咬合干扰后大鼠双侧肌肉中ADP、乳酸或pH值水平未见变化（P>0.05）。
咬合干扰影响大鼠咀嚼肌能量代谢产物的含量，这可能与咬合干扰诱导的咀嚼肌病理过程有关，如肌肉疼痛、功能障碍和纤维结构改变。
