摘要
目的比较脊髓神经元和胶质细胞(星形胶质细胞和小胶质细胞)激活在三种大鼠神经病理性疼痛模型脊髓水平致痛机制中的作用。方法 SD 大鼠24只,体重150g～200g,随机分为4 组,每组6只,分别为对照组、CCI 组、SNL 组和 SNI 组。对照组不实施手术；CCI、SNL、SNI 组分别于左侧制作慢性坐骨神经缩窄损伤模型(CCI)、脊神经结扎模型(SNL)和保留性脊神经损伤模型(SNI)。术前3d 至术后15d 隔日使用机械刺激测定术侧后爪50%缩爪阈值。术后15d 测痛后,用多聚甲醛灌注大鼠,取L_(5,6)脊髓,进行免疫组化实验；用抗原癌基因蛋白 c-Fos、星形胶质细胞标记蛋白(GFAP)和小胶质细胞标记蛋白(OX-42)抗体分别检测神经元、星形胶质细胞和小胶质细胞的激活状况。结果术后7d CCI、SNL、SNI 组术侧50%缩爪阈值均达到最低值,并维持至术后15d；术后15d,对照组、CCI 组、SNL 组和 SNI 组50%缩爪阈值分别为14.1±1.5、2.6±0.5、1.5±0.6、(0.8±0.4)g,大小顺序依次为对照组、CCI 组、SNL 组、SNI 组(P＜0.05)。与对照组比较,CCI、SNL 和 SNI 组Ⅳ～Ⅵ层 c-Fos 阳性神经元数量增加,脊髓背角Ⅰ或Ⅱ层星形胶质细胞及Ⅰ～Ⅳ层小胶质细胞的激活状态升高(P＜0.05), 但 CCI、SNL 和 SNI 组间脊髓背有Ⅳ～Ⅵ层 c-Fos 阳性神经元数量、术侧脊髓背角Ⅰ或Ⅱ层星形胶质细胞的及Ⅰ～Ⅳ层小胶质细胞激活状态差异无统计学意义(P＞0.05)。结论三种神经病理性疼痛大鼠模型中脊髓背角神经元、星形胶质细胞和小胶质细胞的激活状况一致,提示其在脊髓水平致痛机制相似。
Objective To determine if there is any difference in neuronal and glial （astxocytic and micrnglial） activation in the spinal cord in three rat models of neuropathic pain. Methods Twenty-four SD rats weighing 150-200 g were randomly divided into 4 greupa （ n = 6 each） ： Ⅰ control group; Ⅱchronic constrictive injury group （CCI） ; Ⅲ spinal nerve ligation group （SNL） and Ⅳ spared nerve injury （SNI）. No operation was performed in control group. In CCI group left sciatic nerve was exposed and loosely ligated with catgut. In SNL group the L5 spinal nerve was exposed and ligated with silk suture and cut. In SNI group tibial nerve and common fthular nerve were ligated and cut. Pain threshold was measured using plantar tactile stimulator （Ugo, Basile Co. Italy） every other day from 3 days before until 15 days after operation. 50% paw withdrawal threshold was measured using up-and-down sequential mechanical stimulation of different intensity （0.45, 0.70, 1.20, 2.00, 3.63, 5.50, 8.50, 15.10 g） applied to the plantar surface of the injured paw. On the 15^th day after operation after pain threshold was measured the animals were anesthetized with intraperitoneal 10% chloral hydrate 400 mg· kg^-1. The L5.6 segment of the spinal cord was isolated. Neuronal, astrocytic and microglial activation was determined by immuno-histochemistry with antibodies of c-Fos （a proto-oncogene protein）, GFAP （an astrocyte marker） and OX-42 （a microglial marker）. Results The 50 % paw withdrawal threshold reached the lowest level on the 7^th day after operation. The lowest level was maintained until the 15^th day ＇after operation in group CCI, SNL and SNI. The 50% paw withdrawal threshold was （14.1 ± 1.5） g in control group, （2.5 ± 0.5） g in CCI group, （1.5 ± 0.6） g in group SNL and （0.8 ± 0.4） g in group SNI. The number of c-Fos positive neurons in laminae Ⅳ-Ⅵ of dorsal horn was significantly greater in group CCI, SNL and SNI than in control group, but there was no significant difference among the 3 peripheral nerve injury groups. The activation of astrocytes and microglias in laminae Ⅰ-Ⅳ of dorsal horn was significantly increased in group CCI, SNL and SNI than in control group but there was no significant difference among the 3 peripheral nerve injury groups. Conclusion There is no significant difference in activation of neurons and astrocytes and microglias in the ipsilateral dorsal horn among the 3 pain models.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2006年第1期71-74,共4页
Chinese Journal of Anesthesiology
