尼卡地平对谷氨酸诱导大鼠海马星形胶质细胞损伤的影响

目的:观察不同浓度尼卡地平对谷氨酸诱导大鼠海马星形胶质细胞损伤的影响。方法:取新生2～3 dSD大鼠海马星形胶质细胞,原代纯化培养3周。将细胞随机分6组(n=9):正常对照组(C组)加入Hanks液;谷氨酸组(G组)加入谷氨酸至终浓度500μmol/L;尼卡地平组(N组)加入尼卡地平至终浓度10μmol/L;GN1、GN2、GN3组先加入谷氨酸至终浓度500μmol/L,10 m in后分别加入尼卡地平至终浓度1、5、10μmol/L。培养30 m in后检测海马星形胶质细胞内游离钙浓度([Ca2+]i),继续培养24 h检测各组细胞凋亡及丙二醛(MDA)含量、超氧化物歧化酶(SOD)和谷胱甘肽(GSH)活性,免疫荧光细胞化学法检测胶质纤维酸性蛋白(GFAP)表达并观察细胞形态学的改变。结果:与C组比较,G组和GN1组细胞大量凋亡,未凋亡的星形胶质细胞增生肥大;GFAP表达、[Ca2+]i及MDA含量升高,SOD和GSH活性均降低(P<0.01);G、GN1组间比较差异无统计学意义(P>0.05)。与G组比较,GN2组和GN3组凋亡明显减少,细胞形态正常;GFAP表达、[Ca2+]i及MDA含量降低,SOD和GSH活性升高。结论:尼卡地平通过抑制细胞内钙超载和脂质过氧化反应,清除自由基而抑制了谷氨酸诱导海马星形胶质细胞损伤,其抑制程度与剂量有关。     

坐骨神经慢性压迫性损伤大鼠相应脊髓背角神经元KATP通道表达的变化

目的 探讨脊髓背角神经元KATP通道(ATP-sensitive potassium channel)在慢性神经病理性疼痛所致机械痛觉超敏中的作用.方法 雄性SD大鼠(体重250～350 g),随机分为两组:坐骨神经慢性压迫性损伤组(chronic constriction injury,CCI组)6只,假手术组(sham组)6只.在术前1 d、术后1、5、10、14 d分别测量各组大鼠机械缩足阈值(mechanical withdrawal threshold,MWT)的变化,于第14天行灌注固定,取腰段脊髓切片后行KATP通道的免疫组织化学染色,观察各组大鼠腰段脊髓背角神经元KATP通道免疫组织化学染色后积分光密度(IOD)值的变化.结果 坐骨神经慢性压迫性损伤模型大鼠自术后第5天起出现明显的机械性异常性疼痛,持续到术后14 d;而假手术组无明显痛觉过敏表现.术后14 d,坐骨神经慢性压迫性损伤模型组大鼠腰段脊髓背角神经元KATP通道IOD值与假手术组比较明显下降,差异有统计学意义.结论 KATP通道在脊髓背角神经元表达的改变可能与神经病理性疼痛所致机械痛觉超敏的发生机制相关,KATP通道可能成为治疗这类疼痛的靶点.     

开胸术后慢性痛大鼠脊髓背角神经元ATP敏感型钾通道表达的变化

目的 评价开胸术后慢性痛大鼠脊髓背角神经元ATP敏感型钾通道(KATP通道)表达的变化.方法 雄性SD大鼠20只,体重250～350 g,采用随机数字表法,将其随机分为假手术组和开胸术后慢性痛组,每组10只.于术前1 d、术后1、5、10、15、20、25、30 d时分别测定机械痛阈,并行冷丙酮实验,记录1 min内大鼠后爪抓挠皮区次数;于术后30d时处死大鼠,取颈至上胸段脊髓,免疫组化法检测KATP通道的表达水平.结果 与假手术组比较,开胸术后慢性痛组大鼠术后5～如d时机械痛阈降低,术后20～30d时后爪抓挠皮区次数增加,术后30 d时胸段脊髓背角神经元KATP通道表达下调(P＜0.05).结论 开胸术后慢性痛大鼠脊髓背角神经元KATP通道表达下调,该变化可能参与了开胸术后慢性痛的病理生理机制.

Abstract：

Objective To evaluate the change in the expression of ATP-sensitive potassium (KATP) channels in spinal dorsal horn neurons in rats with chronic post-thoracotomy pain (CPTP). Methods Twenty male SD rats, weighing 250-350 g, were randomly divided into 2 groups ( n = 10 each): sham operation group and CPTP group. The animals were anesthetized with 10% chloral hydrate 300 mg/kg, tracheostomized and mechanically ventilated. At 1 d before operation, and at 1, 5, 10, 15, 20, 25 and 30 d after operation, paw withdrawal threshold to yon Frey filament stimulation was measured and the acetone test was performed. The responses of the hindpaw to the acetone test within 1 min were recorded. The rats were sacrificed at 30 d after operation, and the cervical and upper thoracic segments of the spinal cord were removed to detect the expression of KATP channels in spinal dorsal horn neurons by immuno-histochemistry. Results Compared with sham operation group, mechanical pain threshold was significantly decreased at 5-30 d after operation, the response frequency was significantly increased at 20-30 d after operstion, and the expression of KATP channels in spinal dorsal horn neurons in the thoracic segments was down-regulsted at 30 d after operation in CPTP group ( P ＜ 0.05). Conclusion The expression of KATP channels in spinal dorsal horn neurons is down-regulated in rots with CPTP,which may be involved in the pathophsiology mechanism of CPTP.     

依达拉奉对大鼠小肠缺血-再灌注所致肺损伤的保护作用

目的探讨依达拉奉对大鼠小肠缺血-再灌注所致肺损伤的保护作用。方法雄性SD大鼠18只,随机均分为假手术组(Sham组),缺血-再灌注组(IR组)和依达拉奉组(E组)。Sham组只分离肠系膜上动脉,不做其他处理;IR组分离肠系膜上动脉,从大鼠尾静脉注射与E组等量的生理盐水后,用无创动脉夹夹闭120min后移去动脉夹,再灌注120min;E组在缺血-再灌注前静脉注射依达拉奉6mg/kg。再灌注120min后采集标本。肺组织HE染色后病理学检测,采集腹主动脉血液检测大鼠血清中TNF-α和IL-6浓度,取肺组织检测髓过氧化物酶(MPO)活性和丙二醛(MDA)浓度。结果与Sham组比较,IR组肺泡上皮细胞广泛水肿、炎性细胞浸润、肺泡肺萎陷、肺毛细血管扩张出血;E组肺组织病理改变较IR组明显改善,肺泡炎性渗出减少;E组病理评分为(2.1±0.7)分,明显低于IR组的(5.7±1.1)分,IR组病理评分明显高于Sham组的(1.5±0.2)分(P0.01);血清中TNF-α和IL-6的浓度明显少于IR组,肺组织中MPO活性和MDA浓度明显低于IR组(P0.01)。结论依达拉奉能够明显改善小肠缺血-再灌注性肺损伤。