鞘内注射U0126对神经痛大鼠脊髓背角磷酸化cAMP反应元件结合蛋白表达的影响  

Effects of intrathecal U0126 on expression of phosphorylated cAMP response element binding protein in spinal cord dorsal horn in a rat model of neuropathic pain

作　　者：宋雪松[1] 杨桐伟[1] 杜波[2] 佟丹梅[3] 杜宝东[2] 曹君利[4] 曾因明[4] 

机构地区：[1]吉林大学白求恩医学部附属第一临床医学院麻醉科,长春市130021 [2]吉林大学白求恩医学部附属第一临床医学院耳鼻咽喉-头颈外科,长春市130021 [3]吉林大学附属第四医院麻醉科,长春市130021 [4]徐州医学院麻醉学重点实验室江苏省麻醉医学研究所

出　　处：《中华麻醉学杂志》2005年第3期183-186,共4页Chinese Journal of Anesthesiology

基　　金：江苏省教育厅省级重点实验室开放课题(KSJ03081)

摘　　要：目的观察鞘内单次注射U0126(有丝分裂素激活蛋白激酶激酶的阻滞剂)对大鼠脊髓背角磷酸化cAMP反应元件结合蛋白(pCREB)表达的影响,探讨细胞外信号调节激酶(ERK)-CREB信号传递通路在神经痛中的作用。方法第一部分40只坐骨神经慢性损伤(CCI)模型大鼠随机分为5组(n=8):U1组、U2组、U3组和U4组分别鞘内注射0.2、0.5、1、和5μgU0126,C组(模型对照组)单次鞘内注射5%二甲基亚矾10μl,另取8只正常大鼠鞘内注射5.0μgU0126作空白对照组。采用vonFrey纤维丝及热痛刺激仪测定大鼠术侧后肢的机械性缩爪阈值和热刺激缩爪阈值。第二部分50只CCI模型大鼠随机分为5组(n=10):T1、T2、T3、T4组分别在鞘内注射5.0μgU0126后0.5、2、6、12h处死,CCI组为模型对照组,另取10只正常大鼠作对照组。采用免疫组织化学方法测定术侧脊髓背角pCREB免疫反应阳性神经元数量,采用免疫印记法测定脊髓背角pCREB表达。结果第一部分空白对照组注射U01265.0μg对机械性缩爪阈值和热刺激缩爪阈值没有影响。与C组比较,U1组注药后各时点及u2组注药后2、6、12、24h时大鼠术侧机械性刺激缩爪阈值及热刺激缩爪阈值差异无统计学意义(P>0.05),U2组注药后0.5h及U3组、U4组注药后0.5、2、6。Objective To investigate the effects of intrathecally (i.t.) administered U0126 (MAPK kinase inhibitor) on the expression of phosphorylated cAMP response element binding protein (pCREB) in the dorsal horn of spinal cord and changes in mechanical and thermal hyperalgesia in a rat model of neuropathic pain and evaluate the role played by the ERK-CREB signal transmission pathway in the mechanism of neuropathic pain.Methods Adult male SD rats weighing 220-300 g were used. Neuropathic pain was produced by chronic constrictive injury (CCI). Four loose ligatures were placed on left sciatic nerve at 1 mm intervals according to the method described by Bennett. The experiment was performed in 2 parts. In part one 48 SD rats were randomly divided into 6 groups (n = 8 each): In group Ⅰ normal rats received a bolus of U0126 5.0 μg i.t. ; in group Ⅱ CCI rats received a bolus of 5% DMSO 10μli.t. ; in group Ⅲ-Ⅳ CCI rats received a bolus of 0.2, 0.5, 1 and 5 μg U0126 (dissolved in 5% DMSO 10 μl) i.t. respectively. Thermal and mechanical paw withdrawal latencies were measured before and at 0.5, 2, 6, 12 and 24 h after intrathecal injection. In part two 60 animals were randomly divided into 6 groups ( n = 10 each): in group Ⅰ normal animals served as blank control; in groupⅡanimals received CCI only; in group Ⅲ-Ⅳ CCI rats were killed at 0.5, 2, 6 and 12 h after intrathecal administration of U0126 5 μg respectively. L4,5 segments of spinal cord were removed. The expression of pCREB was assessed by Western blot analysis ( n = 4) and immunohistochemical analysis ( n = 6). Results Intrathecal U0126 1 μg and 5 μg significantly reversed the mechanical and thermal hyperalgesia induced by CCI of sciatic nerve. Intrathecal U0126 5 μg significantly attenuated the activation of pCREB in the spinal cord dorsal horn induced by CCI and the effects lasted for at least 6 h. Conclusion This study shows that ERK-CREB signal cascade is involved in the mechanism of neuropathic pain.

关 键 词：鞘内注射 脊髓背角 神经痛 磷酸化cAMP反应元件结合蛋白 蛋白表达 有丝分裂素激活蛋白激酶 细胞外信号调节激酶 免疫组织化学方法 PCREB 神经病理性疼痛 机械性刺激 信号传递通路 模型大鼠 正常大鼠 二甲基亚矾 对照组 

分 类 号：R96[医药卫生—药理学]