【作者】 张婧；

【导师】 容俊芳；

【作者基本信息】 河北医科大学 ， 麻醉学， 2015， 硕士

【摘要】 目的:术后认知功能障碍(postoperative cognitive dysfunction,POCD)是指患者在麻醉手术后常出现的神经系统并发症,如处理不当,将严重影响患者的预后,尤以老年患者最为显著且不易恢复。认知功能障碍的病理生理机制尚不确切,国内外学者主要提出了以中枢胆碱能系统异常、氨基酸类等神经递质代谢异常、手术应激炎症反应、神经元凋亡、Aβ神经毒性和海马突触可塑性的损伤等为主的假说。POCD的病理生理机制并非是单一因素造成的,而是由许多复杂因素综合作用而成。有研究表明,POCD的发生与中枢胆碱能系统异常有关,抗胆碱药物的应用可明显影响空间、学习记忆等认知功能。东莨菪碱是一种外周作用较强的抗胆碱能药物,将东莨菪碱注射到大鼠海马腹侧和丘脑中间背侧可减少大鼠海马内胆碱能递质的含量,损害大鼠的空间、学习记忆等功能。谷氨酸(glutamate,Glu)是中枢内典型的兴奋性神经递质,γ-氨基丁酸(Gamma-aminobutyric acid,GABA)则是典型的抑制性神经递质,二者均可参与到学习、记忆等多种中枢神经活动。另有研究表明,神经甾体孕酮(Progesterone,PROG)可通过调节中枢氨基酸类神经递质系统,降低神经系统的兴奋性毒性,从而起到神经保护的作用。因此,本研究拟通过大鼠腹腔注射东莨菪碱,建立大鼠认知功能障碍模型并行孕酮干预,评价孕酮对大鼠认知功能障碍的影响。方法:健康雄性SD大鼠40只,2月龄,体重130~150 g,采用随机数字表法,将其分为4组(n=10):盐水对照组(C组)、东莨菪碱组(S组)、孕酮干预组(S+P组)和单纯孕酮组(P组)。通过采用腹腔注射东莨菪碱(1.8 mg/kg)的方法建立大鼠认知功能障碍模型。S组腹腔注射东莨菪碱1.8 mg/kg,S+P组腹腔注射东莨菪碱1.8 mg/kg和孕酮8 mg/kg,P组腹腔注射等容量的孕酮8 mg/kg和生理盐水,C组腹腔注射等容量的生理盐水。4组大鼠注射药物后即刻行旷场实验,观察大鼠腹腔内注射药物前10 min(T0)及注射药物后1 h内每10 min(T1-T6)大鼠的情绪及行为学变化,记录周边格和中央格跑格数、中央格停留时间、垂直运动次数、修饰次数和修饰时间。于旷场实验结束后第7天,行Y-型电迷宫测试,观察大鼠的学习记忆等认知功能的变化情况。Y-型电迷宫测试完毕后即刻处死大鼠,取海马组织,采用苏木精-伊红染色(HE染色)法观察海马组织的形态学变化,采用免疫组化法测定海马组织GLU和GABA的含量。结果:与C组比较,S组与S+P组注药后在T1-4时点大鼠周边跑格数和中央格跑格数增加,中央格停留时间延长,垂直运动次数增加,修饰次数减少和修饰时间缩短,第7天Y-型电迷宫测试中大鼠总训练次数增加,达标时间延长,Y-型电迷宫测试后大鼠海马组织GLU含量升高,GABA含量降低,海马组织细胞形态结构被破坏,边界模糊不清,细胞核皱缩,整体细胞结构排列松散,出现变性甚至坏死,其病理损伤程度加重(P<0.05);P组上述指标比较差异无统计学意义(P>0.05)。与S组比较,S+P组注药后在T1-4时点大鼠周边跑格数和中央格跑格数减少,中央格停留时间缩短,垂直运动次数减少,修饰次数增加和修饰时间延长,在Y-型电迷宫测试中大鼠总训练次数减少,达标时间时间缩短,Y-型电迷宫测试后大鼠海马组织GLU含量降低,GABA含量升高,海马组织细胞形态结构被破坏程度减轻,排列松散情况好转,神经元的变性、坏死减少,其病理损伤程度减轻(P<0.05)。结论:腹腔注射孕酮可改善东莨菪碱所致大鼠的认知功能障碍程度,其机制可能与孕酮可调节海马组织谷氨酸和γ-氨基丁酸的含量有关。更多还原

【Abstract】 Objective : Postoperative cognitive dysfunction(POCD) refers to the common neurological complications in anesthesia in patients after operation, if handled properly, will seriously affect the prognosis of patients, especially in elderly patients with the most significant and difficult to recover. Pathological and physiological mechanisms of POCD is not exact, domestic and foreign scholars mainly put forward the hypothesis about central cholinergic system, neurotransmitters such as amino acids, surgical stress inflammation, neuronal apoptosis,α beta neurotoxicity and damage of hippocampal synaptic plasticity.The pathophysiology of POCD is not created by single factor, but rather consists of many complex factorscomprehensive action. Research shows that, the happening of POCD is related with the central cholinergic system abnormalities, application of anticholinergic drugs can significantly affect space, cognitive functions such as learning and memory.Scopolamine is an anticholinergic drug, and play a strong role in peripheral.Scopolamine will be injected into the ventral of bilateral hippocampus and the dorsal of medial thalamic of rats, in this way can reduce the rat hippocampal cholinergicneurotransmitters, while damaging space,cognitive functions such as learning and memory.Glutamic acid(Glu) is the excitatory neurotransmitter in the central nervous system in typicaliy, gamma aminobutyric acid(GABA)are inhibitory neurotransmitter typicaliy, both of them can be involved in learning, memory and other central nervous activity. Another neurosteroid progesterone(PROG) can reduce the nervous system excitable toxicity by adjusting the central amino acid neurotransmitter system, and thus play a neuroprotective role. And PROG can dependent the concentration to inhibite the neurotoxic effect induced by α beta so that improving the survival rate of neurons, and improve- ting the cognitive function.Therefore, this study intends to simulatie the suppression environment of central cholinergic system after general anesthesia by intraperitoneal injection of scopolamine of rats, to establish the rat model of POCD in parallel by progesterone intervention, and evaluate the effection of POCD in rats.Methods:40 healthy two-month-old male SD rats,weighing130~150g. Using a random number table,divide these 40 rats into four groups(n=10) : saline control group( group C),scopolamine group( group S),progesterone in the intervention group( group S + P)and pure progesterone group( group P). Group S simulate the inhibition of neurotransmitter acetylcholine environment by acetylcholine after general anesthesia by peritoneal injection of scopolamine( 1.8 mg / kg), establish the animal model of rat COPD. Group S was intraperitoneally injected scopolamine( 1.8 mg / kg). Group S + P were intraperitoneally injected with scopolamine(1. 8 mg / kg) and progesterone( 8 mg / kg). Group C was intraperitoneally injected equal volume of saline.Put the 4 groups of rats into the self-made open field test after injected the drug immediately, observe of the changes in mood and behavior of rats within 10 min before(T0)and every 10 min within 1h after intraperitoneal injection of drugs(T1-T6), record the central and peripheral run lattice number, residence time, erect inquiry behavior times, modification times, and the time of modification. In the seventh days at the end of the open field test, run the Ytype maze test to observe the changes of cognitive function such as learning and memory ability of rats. After the Y- type electric maze test the rats were killed immediately,and the hippocampal neurons were taken, hematoxylin eosin staining(HE staining) method was used to observe the morphological changes of hippocampal neurons, and Immunohistochemical method was used to determinate the content of GLU and GABA in hippocampal neurons.Results:Compared with group C,the peripheral run lattice number and the central run lattice number were increased in group S and group S+P at the time point of T1-4 after injection, and also the central cell residence time was prolonged, the number of vertical movement were increased,the modification times and the time of modification were reduced. At the seventh days, the number of total training was increased in Y- type electric maze test in rats, and the standard time was prolonged.After the Y- type electric maze test, the content of GLU was increased in hippocampal neurons of rats, and the content of GABA was decreased.The morphological structure of hippocampus neuron cell is destroyed,the boundary is blurred,cell shrinkage,the whole cell structure arranged loosely,degeneration or even death was occer,and the pathological injury was aggravated(P<0.05).No significant differences in the P group(P>0.05).Compared with group S, the peripheral run lattice number and the central run lattice number were reduced in group S+P at the time point of T1-4 after injection,and also the central cell residence time was reduced, the number of vertical movement were reduced,the modification times and the time of modification were increased. At the seventh days, the number of total training was reduced in Y- type electric maze test in rats, and the standard time was reduced. After the Y- type electric maze test, the content of GLU was reduced in hippocampal neurons of rats,and the content of GABA was increased.The morphological structure of hippocampus neuron cell is destroyed,cell swelling, the situation of morphology incompletely and arrangement was improved, the degeneration and necrosis of neurons were decreased, and the pathological injury was reduced(P<0.05).Conclusion: Intraperitoneal injection of progesterone can ameliorate scopolamine induced delirium symptoms,probably be related to the acetylcholine in vivo of rats and the balance disorders between GLU and GABA.更多还原