谷氨酸和辣椒素诱发的肌肉疼痛对男性下颌运动功能的交互作用。

Interactions of glutamate and capsaicin-evoked muscle pain on jaw motor functions of men.

机构信息

Center for Sensory-Motor Interaction, Orofacial Pain Laboratory, Aalborg University, DK-9220 Aalborg, Denmark.

出版信息

Clin Neurophysiol. 2010 Jun;121(6):950-6. doi: 10.1016/j.clinph.2010.01.015. Epub 2010 Feb 12.

DOI:10.1016/j.clinph.2010.01.015

PMID:20153690

Abstract

OBJECTIVE

The aim of the study was to investigate the interaction between glutamate and capsaicin-evoked muscle pain on human jaw motor functions.

METHODS

Fifteen male volunteers participated. Glutamate or capsaicin or isotonic saline, in a paired-sequence order, was injected randomly into the right or left masseter muscle. Two injections were given in a double-blinded design 25 min apart in one session/week over four weeks: isotonic saline (A1) followed by glutamate (A2), capsaicin (B1) followed by glutamate (B2), isotonic saline (C1) followed by capsaicin (C2), and glutamate (D1) followed by capsaicin (D2). The resting electromyographic (EMG) activity of the right and left masseter muscles, maximum voluntary bite force (MVBF), and maximum voluntary jaw opening (MVJO) were recorded before and after injection and subsequently at 5-min intervals for 50 min. The pain intensity was recorded on a 0-10 numerical rating scale during each MVBF or MVJO jaw function.

RESULTS

Resting EMG activity was significantly increased after 5 min of D2 (ANOVA: P=0.028) injection. The percentage change (compared with baseline) in EMG activity was significantly different between D2 (116.1+/-6.1%) and C2 (102.1+/-3.4%) injections (paired t-test: P=0.039). The MVBF and MVJO were significantly decreased after injection of glutamate or capsaicin, however, there was no significant difference in the relative decrease between A2 and B2, or between C2 and D2 at any time point (P>0.152). There was a significantly higher peak pain rating after D2 compared to C2 during MVBF or MVJO (P<0.022), whereas no significant difference in peak pain ratings was found between A2 and B2 (P>0.084). There were significant negative correlations between pain ratings and MVBF or MVJO (Pearson correlation: P<0.001).

CONCLUSIONS

The results indicate that intramuscular administration of glutamate and capsaicin induces muscle pain which has the potential to perturb some normal jaw motor functions.

SIGNIFICANCE

The present findings suggest that peripheral glutamate and capsaicin receptor mechanisms interact to affect some jaw motor as well as sensory (i.e. pain) functions and provide new insights into the complexity of orofacial pain. Management approaches that target the peripheral nervous system and receptor mechanisms may prevent such changes in jaw motor function.

摘要

目的

本研究旨在探讨谷氨酸与辣椒素诱发的肌肉疼痛在人类下颌运动功能中的相互作用。

方法

15 名男性志愿者参与了此项研究。将谷氨酸或辣椒素或等渗盐水以配对序列的方式随机注入右侧或左侧咬肌。在一个疗程中，每周进行两次双盲设计的注射，间隔 25 分钟：等渗盐水（A1）后注射谷氨酸（A2），辣椒素（B1）后注射谷氨酸（B2），等渗盐水（C1）后注射辣椒素（C2），然后注射谷氨酸（D1），最后注射辣椒素（D2）。在注射前和注射后以及随后的 50 分钟内，记录右侧和左侧咬肌的静息肌电图（EMG）活动、最大自主咬合力（MVBF）和最大自主张口度（MVJO）。在每次进行 MVBF 或 MVJO 下颌功能时，使用 0-10 的数字评分量表记录疼痛强度。

结果

D2（ANOVA：P=0.028）注射后 5 分钟，静息 EMG 活动显著增加。与基线相比，D2（116.1+/-6.1%）和 C2（102.1+/-3.4%）注射之间的 EMG 活动百分比变化（配对 t 检验：P=0.039）存在显著差异。注射谷氨酸或辣椒素后，MVBF 和 MVJO 均显著下降，但在任何时间点，A2 和 B2 之间或 C2 和 D2 之间的相对下降均无显著差异（P>0.152）。在进行 MVBF 或 MVJO 时，D2 后的峰值疼痛评分明显高于 C2（P<0.022），而 A2 和 B2 之间的峰值疼痛评分无显著差异（P>0.084）。疼痛评分与 MVBF 或 MVJO 之间存在显著的负相关关系（Pearson 相关：P<0.001）。