大鼠面部慢性炎症痛导致三叉神经节表达P2X3神经元表型的转变  

FACIAL CHRONIC INFLAMMATORY PAIN INDUCES PHENOTYPIC CHANGES OF NEURONS-EXPRESSING P2X3 IN RAT TRIGEMINAL GANGLION

作　　者：刘羊[1] 殷光甫[1] 胡道松[1] 林传友[1] 戴甲培[1] 

机构地区：[1]华中科技大学同济医学院神经生物学系,武汉430030

出　　处：《中国组织化学与细胞化学杂志》2006年第6期674-678,共5页Chinese Journal of Histochemistry and Cytochemistry

基　　金：国家自然科学基金资助(39970240)

摘　　要：目的研究大鼠面部慢性炎症痛与三叉神经节内表达P2X3受体亚型神经元细胞大小和表型变化之间的关系。方法参照Neumann(1996)报道的研究方法,采用大鼠面部皮下注射松节油建立慢性炎症痛模型,用热测痛的方法测定面部皮肤的痛阈值,每天一次,连续测15d。用免疫组织化学技术观察大鼠面部慢性炎症后第5d三叉神经节内感觉神经元P2X3受体的表达。采用体视学的方法测量表达P2X3神经节细胞大小及表型的变化。结果炎症侧大鼠面部痛阈值与对照组相比明显降低,在第5d达到最低值,以后逐渐恢复,第13d开始痛阈恢复正常水平。炎症侧三叉神经节内表达P2X3神经元的平均细胞表面积(721±12μm2)与对照组(616±8μm2)相比明显增大(P<0·01)。进一步观察发现表达P2X3小细胞群(<950μm2)的表面积由炎症前的537±13μm2增加到炎症后的582±15μm2(P<0·05)而且小细胞占总细胞的数量比例由炎症前的42·2±3·2%增加到炎症后的51·8±3·5%(P<0·05);而表达P2X3受体的大细胞(>950μm2)的数量比例由炎症前的6·5±1·9%增加到炎症后的12·8±2·2%(P<0·05)。结论面部慢性炎症痛时,其三叉神经节内表达P2X3受体神经元的表型可发生改变,这可能与面部痛觉过敏和触诱发痛的形成有密切关系。Objective To explore whether peripheral chronic inflammation could lead to phenotypic changes of neurons expressing P2X3 in the trigeminal ganglion of rats. Methods The model of facial chronic inflammatory pain was established by hypodermic injection of turpentine oil according to the method of Neumann （1996）. The pain threshold of facial skin was measured once a day for 15 days using a thermal measurement apparatus of pain. Immunohistochemical staining for P2X3, one subtype of P2X receptor, was carried out in the trigeminal ganglions ipsilateral and contralateral to the inflammation 5 days after the facial injection of turpentine oil. The size of the profiles of neurons expressing P2X3 was measured by an image analysis system. Results The pain threshold reached the lowest value at 5d and recovered to the normal at 13d after inflammation. The average size of the profiles of trigeminal ganglion cells expressing P2X3 was 721±12μm^2 in the inflammatory group, significantly increased compared with that in the control group （616±8μm^2） （P〈0.01）. Furthermore, it was found that the area size of the small-sized ganglion cells＇ profile expressing P2X3 （〈950μm^2） increased as compared with that in the control （582±15μm^2 vs 537±13μm^2, P〈0. 05）, and the percentage of the small-sized cells expressing P2X3 to the total cells increased also （42.2±3. 2% vs 51.8±3.5%, P〈0.05）, while the percentage of the large-sized of P2X3- positive cells （〉950μm^2） increased from 6.5±1.9% to 12. 8±2.2% （P〈0.05） after inflammation. Conclusion Facial chronic inflammatory pain induces phenotypic changes of neurons expressing P2X3 in the trigeminal ganglion of rats, which may has an intimate correlation with the development of facial inflammatory hyperalgesia and allodynia.

关 键 词：痛觉过敏 触诱发痛 P2X3受体 三叉神经节 

分 类 号：R322.9[医药卫生—人体解剖和组织胚胎学]