外周N-甲基-D-天门冬氨酸受体在福尔马林外周注射引起长时程痛敏中的作用

Peripheral N-methyl-D-aspartate Receptors Involved in Long-term Hyperalgesia Induced by Peripheral Injection of Formalin in Rats

目的观察外周N-甲基-D-天门冬氨酸(NMDA)受体对福尔马林外周注射所致长时程痛敏的作用。方法雄性SD大鼠脚掌注射福尔马林,之前注射或不注射MK-801。免疫组化方法检测脊髓背角小胶质细胞OX-42表达,测定热辐射痛行为。结果注射MK-801侧脊髓背角Ⅰ、Ⅱ层小胶质细胞OX-42阳性表达水平较对侧(仅注入福尔马林侧)明显降低。单独注入福尔马林后第3天发生热痛敏,第7天达高峰,第10天仍未完全恢复至正常值;外周应用MK-801后,热痛敏反射潜伏期延长。结论NM-DA受体参与长时程痛敏的产生和维持。

Objective To investigate the role of peripheral N-methyl-D-aspartate （NMDA） receptors in the tong-term hyperalgesia induced by peripheral injection of formalin in rats. Methods Formalin was injected in the paws of the SD rats with or without the MK-801 pre-injection. OX-42 expressions in the dorsal horn were observed, and the paw withdrawal thermal latency was measured. Results The OX-42 expression decreased and the paw withdrawal thermal latency prolonged in rats with MK-801 pre-injection. Conclusion Peripheral NMDA receptors may be involved in the long term hyperalgesia.