海马胶质细胞活化在七氟醚诱发老年大鼠认知功能损害中的作用
发布时间：2018-08-03 07:37
【摘要】：认知功能障碍是麻醉手术后常见的神经系统并发症,已成为影响老年人术后恢复进程和生活质量的重大问题[1]。七氟醚是临床常用的吸入性麻醉药,对术后认知功能有影响[2],但发生机制尚不明确。因此深入了解七氟醚诱发术后认知功能障碍的机理以及找到适宜七氟醚麻醉深度减少甚至消除认知功能障碍的发生一直是麻醉学科研的热点和难点。有研究表明,手术、麻醉引起的中枢神经炎症反应是术后认知功能障碍发生的主要机制之一[3]。而干扰中枢神经系统炎症反应可以改善术后认知功能,降低POCD的发生率[4-7]。胶质细胞是中枢炎症反应的重要组成部分,其活化后产生的炎症因子及形态的改变可诱发炎症反应,直接或间接损伤神经元产生神经毒性进而影响认知功能[3,8],如过度增生的星形胶质细胞可以抑制轴突再生、损伤神经组织,过度活化的小胶质细胞具有神经毒性,可以产生并释放潜在的神经毒性物质破坏邻近的神经元。有研究表明吸入一定浓度七氟醚可改善认知功能[9],也有结果表明七氟醚对老年大鼠学习记忆相关的认知功能的影响具有剂量依赖性[10-12]。因此,我们预测七氟醚可能通过激活神经系统胶质细胞,释放相关炎症因子参与中枢神经系统炎症反应而对认知功能产生影响。 本研究拟在复合胫骨骨折内固定术的基础上探讨诱发老年大鼠术后认知功能障碍的七氟醚麻醉浓度,并进一步探讨胶质细胞活化在七氟醚诱发POCD中的作用机制,以探究适宜的麻醉深度,为降低临床中术后认知功能障碍的发生率提供更多的理论依据。 第一部分：不同浓度七氟醚麻醉对老年大鼠术后认知功能的影响 目的：筛选诱发老年大鼠术后认知功能障碍的七氟醚麻醉浓度。 方法：健康雄性Wistar大鼠96只,体重600～650g,19～20月龄,采用随机数字表法分为6组(n=16)：对照组(C组)、丙泊酚组(P组)、丙泊酚+手术组(PS组)、2.4%七氟醚+手术组(S1组)、3.1%七氟醚+手术组(S2组)、3.6%七氟醚+手术组(S3组)。C组、P组、PS组给予吸入30%O22h,S1组、S2组、S3组分别给予吸入2.4%、3.1%、3.6%七氟醚2h,同时P组、PS组给予丙泊酚(0.5～0.7mg-kg-1·min-1)尾静脉持续输注2h,其余各组以相同速度给予0.9%NaCl注射液尾静脉持续输注2h,PS组、S1组、S2组、S3组在麻醉期间行胫骨骨折切开复位内固定手术。各组分别取8只大鼠于术后1d、3d、7d分别进行Y迷宫空间探索实验和恐惧条件化实验测定大鼠空间工作记忆和恐惧记忆能力,分别于实验周期开始、结束时测定记录大鼠基础体重、7日后体重,在整个实验周期中,定量观察大鼠摄食情况,综合评估老年大鼠术后认知功能,筛选出诱发老年大鼠认知功能障碍的七氟醚浓度组即SS组。 结果：与C组比较,其余各组在训练期各个训练阶段的僵直时间百分比组间差异无统计学意义(P0.05),PS组、S1组、S2组、S3组表现为饮食量下降,体重下降,(P0.05),其中S3组体重下降明显,(P0.01),于术后1d、3d、7d在各臂中的穿梭次数减少、在新异臂的停留时间缩短、场景相关僵直百分比降低、条件诱导僵直百分比降低(P0.05)；与PS组比较,S3组于术后1d、3d时穿梭次数减少及在新异臂停留时间缩短,于术后1d时场景相关僵直百分比降低,于1d、3d、7d时条件诱导僵直百分比降低(P0.05)； 结论：给予高浓度(3.6%,1.5MAC)七氟醚吸入麻醉可诱发老年大鼠术后认知功能障碍的发生。 第二部分：探讨胶质细胞活化在七氟醚诱发老年大鼠术后认知功能障碍中相关调控机制 目的：探讨胶质细胞活化在七氟醚诱发老年大鼠术后认知功能中相关调控机制。 方法：健康雄性Wistar大鼠144只,体重600～650g,19～20月龄,随机分为4组(n=36)：对照组(C组)、丙泊酚组(P组)、丙泊酚+手术组(PS组)、3.6%七氟醚+手术组(SS组)。于术后1d、3d、7d分别取6只大鼠,采用免疫荧光法检测海马各亚区小胶质细胞和星形胶质细胞的形态及CD68和GFAP的表达水平,采用Western blot法检测海马IL-1β、IL-6和TNF-α的蛋白表达水平。 结果：与C组比较,PS、SS组于术后1d、3d、7d时小胶质细胞CD68和星形胶质细胞GFAP、海马IL-1β、IL-6和TNF-α蛋白表达增加(P0.05),与PS组比较,SS组在1d、3d时海马CD68、GFAP、IL-11β、IL-6和TNF-α蛋白表达增加(P0.05)。PS、SS组在不同时点小胶质细胞和星形胶质细胞的形态发生变化。 结论：七氟醚诱发老年大鼠术后认知功能障碍这一过程可能与可增强术后海马胶质细胞的活化有关。
[Abstract]:Cognitive dysfunction is a common neurological complication after anesthesia, which has become a major problem affecting the process of recovery and quality of life in the elderly. [1]. sevoflurane is a commonly used inhalation anesthetic, which affects the postoperative cognitive function of [2], but the mechanism is unclear. Therefore, a thorough understanding of the cognitive work of sevoflurane induced operation has been made. It is a hot and difficult point in the research of Anesthesiology that the mechanism of ability to be able to be impaired and to find a suitable depth of sevoflurane anesthesia and to reduce the occurrence of cognitive dysfunction is a hot and difficult point. Response can improve postoperative cognitive function and reduce the incidence of POCD. [4-7]. glial cells are important components of central inflammatory reaction. The inflammatory factors and morphological changes produced after activation can induce inflammatory reactions, and directly or indirectly damage neurons to produce neurotoxicity and then affect cognitive function [3,8], such as hyperproliferative astrocytes. The stromal cells can inhibit axon regeneration, damage the nerve tissue, and the over activated microglia have neurotoxicity, which can produce and release potential neurotoxic substances to destroy adjacent neurons. Some studies have shown that inhaling a certain concentration of sevoflurane can improve cognitive function [9], and the results show that sevoflurane has a learning and memory phase in old rats. The effects of cognitive function are dose dependent [10-12]., so we predict that sevoflurane may affect the cognitive function by activating the nervous system glial cells and releasing related inflammatory factors to participate in the central nervous system inflammatory response.
On the basis of internal fixation of composite tibial fracture, the aim of this study is to explore the anesthetic concentration of sevoflurane induced by postoperative cognitive impairment in old rats, and to further explore the mechanism of the action of glial activation in sevoflurane induced POCD in order to explore the appropriate depth of anesthesia and to reduce the incidence of postoperative cognitive dysfunction. More theoretical basis.
Part I: effects of different concentrations of sevoflurane on postoperative cognitive function in aged rats
Objective: to screen sevoflurane anesthesia for inducing postoperative cognitive dysfunction in aged rats.
Methods: 96 healthy male Wistar rats, weighing 600 to 650g, 19~20 months old, were divided into 6 groups (n=16): control group (group C), propofol group (group P), propofol + operation group (group PS), 2.4% sevoflurane + operation group (group S1), 3.1% sevoflurane + operation group (S2 group), 3.6% sevoflurane + operation group (S3 group).C group, P group, PS group was given inhalation 22h, group S1, group S2, and group S3 were given 2.4%, 3.1%, 3.6% sevoflurane 2h, and group P, PS group was given propofol (0.5 ~ 0.7mg-kg-1 min-1) tail vein for continuous infusion of 2H. In each group, 8 rats were taken at 1D, 3D, and 7d after the operation. The spatial working memory and fear memory ability of the rats were measured by the Y maze experiment and the fear conditioned experiment respectively. At the beginning of the experiment, the basal body weight of the rats was recorded at the end of the experiment. The weight of the rats was recorded after 7 days, and the feeding situation of the rats was observed in the whole experimental period. Combined assessment of postoperative cognitive function in elderly rats, sevoflurane concentration group induced by cognitive impairment in elderly rats was screened out, namely SS group.
Results: compared with the C group, there was no significant difference between the other groups at each training stage in the training phase (P0.05). Group PS, group S1, S2 group, and S3 group showed decreased diet and weight loss, (P0.05), and S3 group weight decreased obviously, (P0.01), 1D, 3D, and 7d in the different arms in the new arm The retention time was shortened, the percentage of the scene related stiffness decreased and the percentage of conditional stiffness decreased (P0.05). Compared with the PS group, the number of shuttles in the S3 group decreased at 1D, 3D and the length of the new arm was shortened, and the relative stiffness percentage decreased at 1D after operation, and the percentage of stiffness induced stiffness decreased (P0.05) at 1D, 3D and 7d.
Conclusion: high concentration (3.6%, 1.5MAC) sevoflurane inhalation anesthesia can induce postoperative cognitive dysfunction in aged rats.
The second part: To explore the mechanism of glial cell activation in sevoflurane induced postoperative cognitive dysfunction in aged rats.
Objective: To explore the mechanism of glial cell activation in sevoflurane induced cognitive function in aged rats.
Methods: 144 healthy male Wistar rats, weighing 600 to 650g and 19~20 months old, were randomly divided into 4 groups (n=36): control group (group C), propofol group (group P), propofol + operation group (group PS), 3.6% sevoflurane + operation group (group SS). 6 rats were taken 1D, 3D and 7d respectively after operation. The microglia and astrocytes in hippocampus subregions were detected by immunofluorescence. The expression of CD68 and GFAP in hippocampus was detected by Western blot.
Results: compared with the C group, PS and SS groups were at 1D, 3D, and 7d in the microglia CD68 and astrocytes GFAP, and the expression of IL-1 beta, IL-6 and TNF- alpha protein in the hippocampus increased (P0.05). The morphology of the cell changes.
CONCLUSION: Sevoflurane-induced cognitive impairment in aged rats may be related to the enhancement of hippocampal glial cell activation.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R614
本文编号：2161059
[Abstract]:Cognitive dysfunction is a common neurological complication after anesthesia, which has become a major problem affecting the process of recovery and quality of life in the elderly. [1]. sevoflurane is a commonly used inhalation anesthetic, which affects the postoperative cognitive function of [2], but the mechanism is unclear. Therefore, a thorough understanding of the cognitive work of sevoflurane induced operation has been made. It is a hot and difficult point in the research of Anesthesiology that the mechanism of ability to be able to be impaired and to find a suitable depth of sevoflurane anesthesia and to reduce the occurrence of cognitive dysfunction is a hot and difficult point. Response can improve postoperative cognitive function and reduce the incidence of POCD. [4-7]. glial cells are important components of central inflammatory reaction. The inflammatory factors and morphological changes produced after activation can induce inflammatory reactions, and directly or indirectly damage neurons to produce neurotoxicity and then affect cognitive function [3,8], such as hyperproliferative astrocytes. The stromal cells can inhibit axon regeneration, damage the nerve tissue, and the over activated microglia have neurotoxicity, which can produce and release potential neurotoxic substances to destroy adjacent neurons. Some studies have shown that inhaling a certain concentration of sevoflurane can improve cognitive function [9], and the results show that sevoflurane has a learning and memory phase in old rats. The effects of cognitive function are dose dependent [10-12]., so we predict that sevoflurane may affect the cognitive function by activating the nervous system glial cells and releasing related inflammatory factors to participate in the central nervous system inflammatory response.
On the basis of internal fixation of composite tibial fracture, the aim of this study is to explore the anesthetic concentration of sevoflurane induced by postoperative cognitive impairment in old rats, and to further explore the mechanism of the action of glial activation in sevoflurane induced POCD in order to explore the appropriate depth of anesthesia and to reduce the incidence of postoperative cognitive dysfunction. More theoretical basis.
Part I: effects of different concentrations of sevoflurane on postoperative cognitive function in aged rats
Objective: to screen sevoflurane anesthesia for inducing postoperative cognitive dysfunction in aged rats.
Methods: 96 healthy male Wistar rats, weighing 600 to 650g, 19~20 months old, were divided into 6 groups (n=16): control group (group C), propofol group (group P), propofol + operation group (group PS), 2.4% sevoflurane + operation group (group S1), 3.1% sevoflurane + operation group (S2 group), 3.6% sevoflurane + operation group (S3 group).C group, P group, PS group was given inhalation 22h, group S1, group S2, and group S3 were given 2.4%, 3.1%, 3.6% sevoflurane 2h, and group P, PS group was given propofol (0.5 ~ 0.7mg-kg-1 min-1) tail vein for continuous infusion of 2H. In each group, 8 rats were taken at 1D, 3D, and 7d after the operation. The spatial working memory and fear memory ability of the rats were measured by the Y maze experiment and the fear conditioned experiment respectively. At the beginning of the experiment, the basal body weight of the rats was recorded at the end of the experiment. The weight of the rats was recorded after 7 days, and the feeding situation of the rats was observed in the whole experimental period. Combined assessment of postoperative cognitive function in elderly rats, sevoflurane concentration group induced by cognitive impairment in elderly rats was screened out, namely SS group.
Results: compared with the C group, there was no significant difference between the other groups at each training stage in the training phase (P0.05). Group PS, group S1, S2 group, and S3 group showed decreased diet and weight loss, (P0.05), and S3 group weight decreased obviously, (P0.01), 1D, 3D, and 7d in the different arms in the new arm The retention time was shortened, the percentage of the scene related stiffness decreased and the percentage of conditional stiffness decreased (P0.05). Compared with the PS group, the number of shuttles in the S3 group decreased at 1D, 3D and the length of the new arm was shortened, and the relative stiffness percentage decreased at 1D after operation, and the percentage of stiffness induced stiffness decreased (P0.05) at 1D, 3D and 7d.
Conclusion: high concentration (3.6%, 1.5MAC) sevoflurane inhalation anesthesia can induce postoperative cognitive dysfunction in aged rats.
The second part: To explore the mechanism of glial cell activation in sevoflurane induced postoperative cognitive dysfunction in aged rats.
Objective: To explore the mechanism of glial cell activation in sevoflurane induced cognitive function in aged rats.
Methods: 144 healthy male Wistar rats, weighing 600 to 650g and 19~20 months old, were randomly divided into 4 groups (n=36): control group (group C), propofol group (group P), propofol + operation group (group PS), 3.6% sevoflurane + operation group (group SS). 6 rats were taken 1D, 3D and 7d respectively after operation. The microglia and astrocytes in hippocampus subregions were detected by immunofluorescence. The expression of CD68 and GFAP in hippocampus was detected by Western blot.
Results: compared with the C group, PS and SS groups were at 1D, 3D, and 7d in the microglia CD68 and astrocytes GFAP, and the expression of IL-1 beta, IL-6 and TNF- alpha protein in the hippocampus increased (P0.05). The morphology of the cell changes.
CONCLUSION: Sevoflurane-induced cognitive impairment in aged rats may be related to the enhancement of hippocampal glial cell activation.
【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R614
【参考文献】
相关期刊论文 前3条
1 付娟;刘俊华;;条件化恐惧消退的神经机制研究进展[J];滨州学院学报;2008年03期
2 张东明;;Y型迷宫实验和Morris水迷宫实验的比较[J];中国医药科学;2011年20期
3 刘志强;张均田;唐民科;;小胶质细胞对成年哺乳动物神经发生的调节作用[J];生理科学进展;2011年01期
，本文编号：2161059
本文链接：https://www.wllwen.com/yixuelunwen/mazuiyixuelunwen/2161059.html
最近更新
教材专著
