从大鼠脊髓背角Iba1的表达探讨天麻素对化疗诱导神经病理性疼痛的作用及其机制

Effects and the mechanism of gastrodin on chemotherapy-induced neuropathic pain through the expression of Iba1 of spinal dorsal horn

目的:观察天麻素对化疗痛大鼠脊髓背角小胶质细胞活化的影响。方法:根据痛阈值大小筛选出合格的SD大鼠30只,采用随机配伍的方法分为5组:对照组、模型组、天麻素低剂量组(30mg/kg)、天麻素中剂量组(60mg/kg)、天麻素高剂量组(120mg/kg)。用隔日腹腔注射长春新碱(125μg/kg)的方法建立化疗痛动物模型,采用不同剂量的天麻素治疗化疗痛大鼠,分别用Electronic vonfrey测痛仪和热刺痛仪测定大鼠机械痛阈值及热痛阈值;免疫荧光法检测脊髓背角小胶质细胞特异性活化标志物Iba1的表达。结果:与对照组比较,模型组大鼠机械痛阈值和热痛阈值明显降低(P<0.05或P<0.01),脊髓背角Iba1表达显著升高(P<0.01);与模型组比较,天麻素治疗组大鼠机械痛阈值与热痛阈值有不同程度的增高(P<0.05或P<0.01),脊髓背角Iba1表达有不同程度的降低(P<0.05或P<0.01)。结论:天麻素能减轻化疗痛大鼠的机械痛敏和热痛敏反应,该作用可能与其抑制脊髓小胶质细胞活化有关。

ABSTRACT AIM： To observe the effects of gastrodin on expression of Ibal in spinal cord in rats with vincristine-induced neuropathic pain. METHODS： SD rats were divided into 5 groups with random block design ： control group, mod- el group, gastrodin group （30 mg/kg, 60 mg/kg,120 mg/kg）. Vincristine （125 μg/kg, i. p. ） was administered to rats on alternate days to establish chemotherapy-induced neuropathic pain model in rat, then treated with different dose of gastrodin. Pain threshold and expression of Ibal was determined respectively. RESULTS： Com- pared with control group, the pain threshold de- creased in model group （P〈0.05 or P〈0.01）. Compared with model group, the pain thresholdincreased in gastrodin groups （30 mg/kg, 60 mg/kg,120 mg/kg） （P〈O. 05 or P〈O. 01）. Moreover, compared with control group, the ex- pression of Ibal increased in model group （P〈0.01）. Compared with model group, the expres- sion of Ibal decreased in gastrodin groups （60 mg/kg,120 mg/kg） （P〈0.05 or P〈0.01）. CONCLUSION： Gastrodin can relieve the chemo- therapy-induced neuropathic pain, probably by inhibiting the activation of spinal dorsal horn mi- croglia.