Cairns Brian E, Wang Kelun, Hu James W, Sessle Barry J, Arendt-Nielsen Lars, Svensson Peter
Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
J Orofac Pain. 2003 Fall;17(4):317-25.
To compare jaw-stretch reflex responses in male and female subjects and to determine whether injection of glutamate into the masseter muscle facilitates these responses in both sexes.
Jaw-stretch reflex responses were evoked with a muscle stretcher, and pain intensity was scored by 11 men and 13 women before and after the injection of glutamate (1.0 mol/L, 0.2 ml) into the masseter muscle. The subjects rated glutamate-evoked pain intensity on a visual analog scale.
Baseline jaw-stretch reflex responses were larger and glutamate injections into the masseter muscle were significantly more painful in women than in men, however, glutamate significantly facilitated jaw-stretch reflex responses in men but not in women.
These results suggest that there is a significant sex-related difference in human jaw-stretch reflex responses and their modulation by painful stimuli. Since one possible function of facilitated jaw-stretch reflex responses during jaw muscle pain may be to reduce jaw mobility and thus protect against further exacerbation of an existing injury, the finding of a sex-related difference in modulation of jaw-stretch reflex responses may prove to be important in clarifying why the prevalence of temporomandibular disorders is greater in women than in men.
比较男性和女性受试者的下颌伸展反射反应，并确定向咬肌注射谷氨酸是否会促进两性的这些反应。
使用肌肉拉伸器诱发下颌伸展反射反应，在向11名男性和13名女性的咬肌注射谷氨酸（1.0摩尔/升，0.2毫升）之前和之后，通过视觉模拟量表对疼痛强度进行评分。受试者对谷氨酸诱发的疼痛强度进行评分。
女性的基线下颌伸展反射反应更大，向咬肌注射谷氨酸时女性的疼痛明显比男性更强烈，然而，谷氨酸显著促进了男性的下颌伸展反射反应，而对女性则没有。
这些结果表明，人类下颌伸展反射反应及其受疼痛刺激的调节存在显著的性别差异。由于在咬肌疼痛期间促进下颌伸展反射反应的一个可能功能可能是降低下颌活动度，从而防止现有损伤进一步加重，因此，下颌伸展反射反应调节中性别差异的发现可能对阐明为什么颞下颌关节紊乱症在女性中的患病率高于男性具有重要意义。
