脊髓细胞外调节激酶1/2在大鼠后足切割痛中的表达和作用

目的：探讨大鼠后足切割后脊髓ERK的表达情况。方法：以大鼠右后足切割作为急性疼痛模型;用免疫组织化学法测试脊髓磷酸化ERK（pERK）表达情况。ERK抑制剂U0126（1μg）在切割前20min或切割后20min鞘内注射。用von Frey纤维测试大鼠机械性痛敏。结果：大鼠后足切割后1min,在切割侧L4-L5脊髓浅层背侧角（板层Ⅰ和板层Ⅱ）ERK被迅速地激活,并在5min达到峰值,随后恢复到基础值。切割前鞘内给予U0126能显著减轻机械性痛敏,然而,切割后鞘内给予U0126对机械性痛敏的作用并不明显。结论：脊髓ERK在大鼠后足切割痛中产生机械性痛敏发挥了重要的作用。

The Expression and Role of ERK1/2 in Spinal Cord in Incisional Pain

Objective： The current study aims to explore the role of ERK in spinal cord in incisional pain. Methods： Rats were re- ceived one hind paw incision; pERK1/2 （p44/42） in spinal cord was measured by immunohistochemistry. ERK inhibitor, U0126 （1μg） was intrathecally injected 20 min before or after incision. Pain hypersensitivity was assessed by von Frey test. Results： The expression of ERK in the ipsilateral L4-L5 spinal superficial dorsal horn （lamina I and II） was activated at lmin immediately after hind paw incision in rats, followed by reaching a peak at 5 min, and then returned to basal level thereafter. Pretreatment with U0126 dramatically attenuated the mechanical pain hypersensitivity induced by hind paw incision. However, U0126 post-treatment had only marginal effect on incision- evoked mechanical pain hypersensitivity. Conclusions： ERK activation in spinal dorsal horn plays an important role in the development of pain hypersensitivity induced by surgical incision.