【作者】 于翠萍；

【导师】 倪家骧；

【作者基本信息】 首都医科大学 ， 疼痛医学， 2007， 硕士

【摘要】 目的观察不同剂量双氯芬酸钠灌胃对坐骨神经结扎(CCI)大鼠机械痛阈,背根神经节(DRG)及脊髓背角P物质(SP)、降钙素基因相关肽(CGRP)表达及胃肠粘膜的影响。探讨口服双氯芬酸钠对治疗神经病理性疼痛的疗效和可能机制,及其对胃肠道的副作用,为临床应用该药时提供参考。方法雄性SD大鼠40只(体重240-260g),随机分为坐骨神经结扎(CCI)组(32只)和假手术组(n = 8)。CCI组又分为: a :双氯芬酸钠组(2mg/kg组, n = 8;4mg /kg组,n = 8;10mg/kg组,n = 8);b对照组(生理盐水1ml,n =8)。自术后第8天分别给予不同剂量双氯芬酸钠及生理盐水灌胃,每日两次共7天。采用自制的Von-Frey纤毛机械刺激器测定灌胃前及灌胃第1、3、5、7天时大鼠右后肢机械刺激缩足反射阈值(PWMT)及用药7天后免疫组化法测定L4-5背根神经节细胞及腰膨大处(L4-5节段)脊髓背角SP和CGRP表达,并在光镜下观察胃肠粘膜结构变化。结果(1)对CCI大鼠机械痛阈的影响:对照组、2mg/kg组、4mg/kg组、10mg/kg组在用药前及用药后各时间点的右后肢PWMT与假手术组相比显著降低(P<0.01)。4mg/kg组在用药第5、7天时右后肢PWMT与用药前及对照组相比显著增加(P<0.01或P<0.05);10mg/kg组用药后各时间点右后肢PWMT与用药前及对照组相比显著增加(P<0.01)。且呈现出剂量依赖效应(P<0.05)。(2)对大鼠胃肠粘膜结构的影响:肉眼观各组大鼠胃窦部、腺体部及肠粘膜均未见溃疡和出血。假手术组、对照组病理切片观胃、空肠粘膜结构完整,未见明显的炎性细胞浸润。2mg/k组病理切片观胃粘膜腺体略有增厚;空肠腺体未见明确变化。4mg/kg组观胃粘膜腺体变少,腺壁变薄;肠绒毛变少、变短,杯状细胞减少。10mg/kg组观胃粘膜腺体增生、变厚、染色变深;肠绒毛变少、变短,肠嗜酸性细胞多,有炎症改变。(3)对大鼠背根神经节(DRG) SP、CGRP表达的影响:对照组、2mg/kg组、4mg/kg组、10mg/kg组SP及CGRP表达的平均光密度值(OD)均明显高于假手术组(P <0.01)。4mg/kg组、10mg/kg组SP及CGRP表达的平均光密度值(OD)明显低于对照组(P<0.01或P<0.05)。(4)对大鼠脊髓背角I、II层SP、CGRP表达的影响:对照组、2mg/kg组、4mg/kg组、10mg/kg组SP及CGRP表达的平均光密度值(OD)均明显高于假手术组(P <0.01)。4mg/kg组、10mg/kg组SP及CGRP表达的平均光密度值(OD)明显低于对照组(P <0.01或P<0.05)。结论1、一定剂量(4 mg/kg、10 mg/kg)双氯芬酸钠灌胃能够减轻CCI大鼠机械性痛敏反应,且具有剂量依赖效应。2、双氯芬酸钠减轻机械痛敏的作用机制可能是使背根神经节和脊髓背角SP、CGRP的表达减少。3、镇痛效果虽有剂量依赖效应,但随之副作用也增加,提示临床应用应严格限制用药剂量。说明双氯芬酸钠治疗神经病理性疼痛的有效剂量同时也会引起胃肠粘膜损害,因而还不是治疗神经病理性疼痛的理想药物。更多还原

【Abstract】 ObjectiveTo obseve the effects of diclofenac sodium on mechanical hyperalgia, substance P （SP） and calcitonin gene-related peptide （CGRP） expression in dorsal root ganglion （DRG） neurons and dorsal horn, as well as the structure of gastrointestinal mucosa in chronic constriction injury （CCI） rats.Materials and MethodsForty male SD rats weighing 240-260g were randomly divided into 5 groups : 1) Sham operation group; 2) Control group （ treated with CCI） ; 3) diclofenac sodium 2mg/kg group; 4) diclofenac sodium 4mg/kg group; 5) diclofenac sodium 10mg/kg group . From 8th day post-ligation. Nature saline, different dose of diclofenac sodium were administered by injecting into gastric cavity twice per day for 7 days according to different groups, respectively. Before and after drug injection(at 1^st、3^rd、5^th、7^th day), the posterior Paw Withdrawal Mechanical Threshold （PWMT） was measured by Von Frey hair, and the expressions of SP and CGRP in L4-5 dorsal root ganglion （DRG） neurons and dorsal horn were detected by immunohistochemistry method. Meanwhile, the structure of gastrointestinal mucosa was observed in light microscope.Results（1） The effects of diclofenac sodium on PWMTAt pre-drug , different time post-drug, the right posterior PWMTs of Control group, diclofenac sodium 2mg/kg group, 4mg/kg group, 10mg/kg group were significantly decreased compared with that of Sham operation group （p<0.01）. At 5^th and 7^th day post-drug, the PWMTs of 4mg/kg group were significantly increased compared with that of pre-durg and control group（P<0.01或P<0.05）. At different time post-drug, the PWMTs of10mg/kg group were significantly increased compared with that of pre-durg and control group（P<0.01）. and the effect of diclofenac sodium was dose-dependent （p<0.05）.（2） The effects of diclofenac sodium on the structure of gastrointestinal mucosa.At 7^th day post-drug, there were no any ulcer and bleeding in gastrointestinal mucosa of all five groups macroscopically. Under microscope, in Sham operation and Control group, the structure of gastrointestinal mucosa was intact without obvious inflammatory cells soakage. In 2mg/kg group, the structure of gastric mucosa was slightly incrassate, but the intestinal mucosa was intact. In 4mg/kg group, gastric mucosa gland became minor, the wall of the gland became tenuis, intestinal villi became minor and short, beaker cell decreased. In 10mg/kg group, gastric mucosa gland was hyperplastic and incrassate, intestinal villi became minor and short, acidophilic cell increased with inflammatory cells soakage.（3） The effects of diclofenac sodium on SP and CGRP expressions in DRG neuronsAt 7^th day post-drug, in Control group, diclofenac sodium 2mg/kg group, 4mg/kg group, 10mg/kg group, the average optical density （OD） of SP and CGRP in the right L4-5 DRG neurons were significantly increased compared with that of sham operation group（P <0.01）.In 4mg/kg group, 10mg/kg group, the average optical density （OD） of SP and CGRP in the right L4-5 DRG neurons were significantly decreased compared with that of control group（P<0.01或P<0.05）.（4） The effects of diclofenac sodium on SP and CGRP expressions in the I, II layerof dorsal horn.At 7^th day post-drug, in Control group, diclofenac sodium 2mg/kg group, 4mg/kg group, 10mg/kg group, the average optical density （OD） of SP and CGRP in the dorsal horn were significantly increased compared with that of sham operation group（P <0.01）.In 4mg/kg group, 10mg/kg group, the average optical density （OD） of SP and CGRP in the dorsal horn were significantly decreased compared with that of control group（P<0.01或P<0.05）.ConclusionsDiclofenac sodium can dose-dependently （4mg/kg,10mg/kg） decrease the mechanical hyperalgia. The possible mechanism might be reducing SP and CGRP expressions in DRG neurons and dorsal horn in CCI rats; When administerd in large dose, it can damage gastrointestinal mucosa obviously, thus this dose shoud be cautious in rats and we should constrain dose in clinic.更多还原