右美托咪定对大鼠脑缺血再灌注损伤后星形胶质细胞的影响

目的: 通过观察右美托咪定(DEX)对大鼠脑缺血再灌注损伤后星形胶质细胞的影响,探讨DEX对抗脑缺血再灌注损伤的作用及其机制。方法: 采用大脑中动脉栓塞法建立大鼠局灶性脑缺血再灌注模型,将SD大鼠随机分为假手术组、单纯脑缺血再灌注组、DEX预处理1组(缺血前30 min腹腔给予DEX 20 μg/kg)及DEX预处理2组(缺血前30 min腹腔给予DEX 40 μg/kg)。缺血再灌注24 h后,观察大鼠神经功能缺失评分,通过HE染色了解脑梗塞后脑组织的病理学变化,采用免疫组化和蛋白免疫印迹方法观察缺血后脑组织星形胶质细胞的变化。结果: DEX预处理能显著改善大鼠神经功能缺失评分,减小大鼠梗死面积,减少缺血区胶质纤维酸性蛋白(GFAP)阳性星形胶质细胞和肿瘤坏死因子α(TNF-α)阳性星形胶质细胞,降低GFAP表达水平。结论: DEX对缺血再灌注损伤的脑组织具有保护作用,其作用机制可能与抑制星形胶质细胞激活有关。     

急性吗啡暴露对大鼠前额叶皮质τ蛋白磷酸化及学习记忆的影响

目的探讨急性吗啡暴露对大鼠前额叶皮质τ蛋白磷酸化及学习记忆的影响。方法40只雄性SD大鼠随机均分成急性吗啡暴露组(M组)和对照组(C组)。M组单次腹腔注射吗啡(30 mg/kg),C组同法注射等量生理盐水。注射后2 h和24 h分别断头处死10只大鼠,免疫印迹技术检测前额叶皮质τ蛋白的磷酸化水平。后处死的大鼠于注射后2、4及24 h分别行水迷宫实验。结果M组注射后2 h时平台寻找时间显著长于C组(P<0.01)。M组大鼠前额叶皮质τ蛋白Ser396和Thr231位点的磷酸化水平于注射后2 h时显著高于C组(P<0.05)。结论急性吗啡暴露可致大鼠学习记忆功能可逆性减退,前额叶皮质τ蛋白过度磷酸化可能与其有关。     

急、慢性吗啡处理对大鼠大脑皮层tau蛋白和神经微丝磷酸化水平的影响

目的:观察急、慢性吗啡处理对大鼠大脑皮质细胞骨架蛋白磷酸化水平的影响,探讨吗啡导致细胞周期依赖性蛋白激酶-5(cyclin dependent kinase-5,CDK5)过度表达与细胞骨架蛋白过度磷酸化的关系。方法:雄性SD大鼠40只,随机均分为急性对照组、急性吗啡处理组、慢性对照组、慢性吗啡处理组。急性吗啡处理组腹腔注射吗啡30mg/kg1次,慢性吗啡处理组腹腔注射吗啡10mg/kg,每天2次(时间8:00、20:00)共10d。采用免疫印迹法测定大鼠大脑皮质tau蛋白和神经微丝的磷酸化水平及CDK5、p35表达水平。结果:(1)与急性对照组比较,急性吗啡处理组tau蛋白和神经微丝磷酸化水平升高,CDK5的表达增加;(2)与慢性对照组比较,慢性吗啡处理组tau蛋白和神经微丝磷酸化水平升高,CDK5的表达无明显变化;(3)与急性吗啡处理组比较,慢性吗啡处理组tau蛋白和神经微丝蛋白磷酸化水平降低;(4)各组间p35表达水平无明显改变。结论:急、慢性吗啡处理可导致大鼠大脑皮质tau蛋白和神经微丝的异常过度磷酸化,但这种变化可能与CDK5的过度表达无关。     

右美托咪定缓解神经病理性疼痛大鼠的痛觉过敏并抑制背根神经节内p-ERK信号通路的激活

目的 观察重复腹腔注射右美托咪定(DEX)对神经病理性疼痛大鼠的痛觉过敏和背根神经节(DRG)中ERK信号通路激活的影响.方法 给坐骨神经部分结扎(PSNL)神经病理性疼痛大鼠重复腹腔注射不同剂量的DEX.观察各组大鼠的机械、热痛觉过敏阈值.行为学测试完成后用免疫荧光和Western blot方法检测大鼠手术侧L5 DRG中p-ERK的表达.结果 (1)腹腔注射DEX 40 μg/kg 7、14 d均明显减轻PSNL诱导的机械、热痛觉过敏(P＜0.05).而腹腔注射DEX20μg/kg对PSNL大鼠疼痛行为学无明显影响.(2)重复腹腔注射40μg/kg DEX 7、14 d p-ERK的平均荧光强度比同一时间点的PSNL组明显减弱(P＜0.05),但仍明显高于对照组(P＜0.05).重复腹腔注射20μg/kg对PSNL大鼠p-ERK的平均荧光强度无明显影响(P＞0.05).(3)Westem blot 结果显示重复腹腔注射40μg/kg DEX 7、14 d明显抑制PSNL诱导的p-ERK的蛋白表达增多(P＜0.05).重复腹腔注射20μg/kg对PSNL大鼠p-ERK的蛋白表达无明显影响(P＞0.05).结论 重复腹腔注射DEX能够减轻神经损伤引起的痛觉过敏,抑制外周初级感觉神经系统中ERK信号通路的激活可能是其缓解的疼痛症状的机制之一.

Abstract：

Objective To investigate the effect of systemic administration of dexmedetomidine, a selective alpha 2 adrenergic receptor agonist, on mechanical and thermal hyperalgesia and dorsal root ganglia ERK activation induced by neuropathic pain. Methods Intraperitoneal injection of dexmedetomidine was repeatedly given once daily for 7 days or 14 days with the first injection one day before partial sciatic nerve ligation ( PSNL) surgery. Mechanical and thermal nociceptive thresholds were assessed in all animals. Then, animals were killed at corresponding time points, and the L5 DRG was removed for L5 DRG ERK activation status analysis by using immunoflurecence and Western blotting. Results (1) Partial sciatic never ligation produced a robust mechanical and thermal hyperalgisia and ERK activation of the L5 DRG in P7 and P14 groups. At the dose of 40 μg/kg, dexmedetomidine significantly attenuated PSNL-induced ipsilateral hyperalgesia on the day 7 and 14 after surgery. But the dose of 20 μg/kg of dexmedetomidine had no effect on pain behaviorl; (2) PSNL-induced up-regulation of mean fluorescence intensity of pERK on ipsilateral side of the L5 DRG was significantly suppressed by day 7, 14 post-PSNL following 40 μg/kg dexmedetomidine application, whereas 20 μg/kg dexmedetomidine had no effect; (3) Western blotting revealed that up-regulation of the protein expression of p-ERK on ipsilateral side of the L5 DRG was significantly inhibited on the day 7, 14 post-PSNL following 40 μg/kg dexmedetomidine application,whereas 20 μg/kg dexmedetomidine had no effect. Conclusion Systemic dexmedetomidine inhibits the activation of ERK signals in L5 DRG, which is possibly associated with its antihyperalgesia in rats with neuropathtic pain.     

右美托咪定缓解神经病理性疼痛大鼠的痛觉过敏并抑制背根神经节内p-ERK信号通路的激活

Objective To investigate the effect of systemic administration of dexmedetomidine, a selective alpha 2 adrenergic receptor agonist, on mechanical and thermal hyperalgesia and dorsal root ganglia ERK activation induced by neuropathic pain. Methods Intraperitoneal injection of dexmedetomidine was repeatedly given once daily for 7 days or 14 days with the first injection one day before partial sciatic nerve ligation ( PSNL) surgery. Mechanical and thermal nociceptive thresholds were assessed in all animals. Then, animals were killed at corresponding time points, and the L5 DRG was removed for L5 DRG ERK activation status analysis by using immunoflurecence and Western blotting. Results (1) Partial sciatic never ligation produced a robust mechanical and thermal hyperalgisia and ERK activation of the L5 DRG in P7 and P14 groups. At the dose of 40 μg/kg, dexmedetomidine significantly attenuated PSNL-induced ipsilateral hyperalgesia on the day 7 and 14 after surgery. But the dose of 20 μg/kg of dexmedetomidine had no effect on pain behaviorl; (2) PSNL-induced up-regulation of mean fluorescence intensity of pERK on ipsilateral side of the L5 DRG was significantly suppressed by day 7, 14 post-PSNL following 40 μg/kg dexmedetomidine application, whereas 20 μg/kg dexmedetomidine had no effect; (3) Western blotting revealed that up-regulation of the protein expression of p-ERK on ipsilateral side of the L5 DRG was significantly inhibited on the day 7, 14 post-PSNL following 40 μg/kg dexmedetomidine application,whereas 20 μg/kg dexmedetomidine had no effect. Conclusion Systemic dexmedetomidine inhibits the activation of ERK signals in L5 DRG, which is possibly associated with its antihyperalgesia in rats with neuropathtic pain.     

AMPK在七氟烷致H4细胞凋亡中的作用研究

目的:探讨AMPK是否会影响七氟烷引起的细胞凋亡,为研究吸入麻醉药致神经毒性的机制提供新的靶点和思路。方法:用4.1%七氟烷处理H4人脑神经胶质瘤细胞6 h,建立七氟烷细胞毒性模型。建模前予以AMPK激动剂(二甲双胍)或AMPK抑制剂(Compound C)进行预处理。运用Westernblot检测AMPK、p AMPK、full-length caspase-3以及caspase-3 fragment的表达情况。结果:在七氟烷致H4细胞凋亡的模型中,通过AMPK激动剂进一步增加七氟烷所致的p AMPK上调,能够减少细胞凋亡。结论:在七氟烷致H4细胞凋亡的模型中,激活AMPK具有细胞保护作用。     

吗啡诱导的CPP复燃大鼠前额叶皮层和海马区EAAT3蛋白表达的变化

目的: 观察吗啡诱导的条件性位置偏爱(CPP)复燃大鼠前额叶皮层和海马区兴奋性氨基酸转运蛋白3(EAAT3)的表达变化,探讨前脑皮层及海马区EAAT3在阿片类药物复吸过程中的作用。方法: 成年雄性SD大鼠40只,随机分为对照组(control)、CPP建立(Es)、消退(Ex)、复燃2 h(Re2)、复燃4 h(Re4)组,每组8只。腹腔注射吗啡(10 mg/kg)连续10 d,建立CPP模型;停止给药使CPP逐渐消退;单次腹腔注射吗啡 2.5 mg/kg诱导已消退的CPP复燃。Western blotting检测各组大鼠前额叶皮层和海马区EAAT3蛋白表达变化。 结果: (1)腹腔注射恒定剂量的吗啡10 mg/kg, Es组大鼠在伴药箱的停留时间比control组明显延长(P<0.05),成功建立CPP模型;待CPP消退后,吗啡2.5 mg/kg腹腔注射诱发Re2和Re4组大鼠在伴药箱的停留时间再次比control组明显延长(P<0.05),CPP复燃。(2)Es组前额叶皮层EAAT3比control组表达减少(P<0.05),CPP消退的Ex组表达回升,在Re4组表达再次减少(P<0.05)。(3)海马区EAAT3在各组表达水平未见明显变化(P>0.05);而Es、Ex组海马CA1区EAAT3比control组表达明显升高(P<0.05)。 结论: 吗啡诱导CPP复燃时,前额叶皮层EAAT3的蛋白表达水平降低,重现CPP建立时的变化,提示阿片类药物复吸行为的形成可能与前脑皮层EAAT3的表达减少有关。     

右美托咪定对老年患者腰-硬联合麻醉的镇静效应

目的 观察右美托咪定对老年腰-硬联合麻醉(CSEA)的镇静效应.方法 选择100例65～79岁、ASA Ⅱ或Ⅲ级拟行(CSEA的患者,随机均分为右美托咪定组(D1、D2、D3组)、丙泊酚组(P组)和空白对照组(C组)五组.记录麻醉前(T0)、CSEA麻醉后(T1)及用药后5 min(T2)、15min(T3)、30 min(T4)、60 min(T5)的MAP、HR、RR、SpO2和Ramsay评分.术后24 h随访患者用药后至结束手术前对有关操作的遗忘程度.结果 T2～T5时,D1、D2、D3、P组Ramsay评分高于T0时(P＜0.05),T3～T5时D2、D3、P组显著高于C组(P＜0.05).T4、T5时P组MAP低于其他各组(P＜0.05).T3～T5时D3组HR慢于其他各组(P＜0.05).术后24 h随访.D1、D2、D3组顺行性遗忘程度高于C组(P＜0.05),与P组相比筹异无统计学意义.结论 静注右美托咪定0.5 μg/kg后以0.2～0.5μg-1·h1输注适合老年患者CSEA的镇静.     

右美托咪定对舌癌患者围术期免疫功能的影响

目的:探讨右美托咪定(Dex)对舌癌患者围术期免疫功能的影响.方法:将ASAⅠ~Ⅱ级拟行舌癌根治全麻择期手术患者30例随机分为右美托咪定组(Dex组)和对照组各15例.全麻诱导前,Dex组持续泵入右美托咪定0.5 μg/kg(溶于10 mL生理盐水),对照组静脉持续泵人生理盐水10 mL,均在10 min内完成.以相同药物快速诱导插管,插管后Dex组以Dex、七氟醚、瑞芬太尼维持;对照组以七氟醚、瑞芬太尼维持.分别于TO(诱导前)、T1(切皮前,诱导后20 min)、T2(切皮后,诱导后50min)测定CD3+、CD4+、CD8+、CD4+/CD8+及NK细胞比例.结果:两组在TO时间点CD3+、CD4+、CD8+、CD4+/CD8+以及NK细胞的分布差异无统计学意义(P>0.05).Dex组各个时间点CD3+、CD4+、CD8+、CD4+/CD8+及NK细胞变化不明显.相对于TO时间点,对照组T1、T2时间点CD3+、CD4+、C D4+/CD8+和NK细胞呈下降趋势,而CD8+升高.和对照组比较,Dex组在T1、T2时闻点CD4+/CD8+、NK细胞升高,而CD8+降低.结论:Dex作为麻醉辅助药物能减轻全麻药物对舌癌患者免疫功能的影响.     

乌司他丁对体外循环冠状动脉搭桥术后早期房颤的影响

目的 :观察术中应用乌司他丁(UTI)对体外循环冠状动脉搭桥术后(CABG)早期房颤(AF)发生率的影响。方法:114例拟行冠脉搭桥术患者随机分为UTI治疗组(U组,n=57)和对照组(C组,n=57)。U组在麻醉诱导后开始恒速静脉泵入1万U/kg,30 min输入完毕,C组以同样方法输入相同剂量的生理盐水。分别于麻醉诱导前(T1)及术后24 h(T2)抽取患者静脉血检测血白细胞、中性粒细胞和淋巴细胞,测定血浆IL-6、CRP浓度,同时行术后24 h动态心电图监测。结果:与C组相比,U组术后24 h内AF发生率显著降低(P0.05);与T1比较,U组术后24 h的NLR显著降低(P0.01),C组NLR显著增加(P0.01);而C组和U组的IL-6、CRP与T1比较无明显改变。结论:UTI可降低体外循环CABG 24h内AF的发生率,机制可能与其降低手术应激产生的炎症反应有关。