不同缺氧方式对幼龄大鼠血清BDNF、HIF-1α水平和海马形态学及认知功能的影响

发布时间：2018-04-21 07:04

本文选题：间歇性缺氧 + HIF-1α　；参考：《广州中医药大学》2017年硕士论文

【摘要】：目的:本实验通过建立常压慢性间歇性缺氧和慢性持续性缺氧的幼龄大鼠模型,探讨不同缺氧方式对幼龄Wistar大鼠血清HIF-1 α、BDNF的水平表达和海马形态学和认知功能的影响及其可能的相关机制。方法:选取(20±2)日龄雄性Wistar大鼠24只,随机数字表法分为3组:NC组,CIH组和CSH组。NC组正常饲养,CIH组间歇缺氧8h每天,CSH组持续缺氧8h每天,两组大鼠连续造模30天。造模完成后记录三组大鼠体重,观察其生长发育情况,Morris水迷宫检测大鼠学习和记忆能力,ELISA检测血清HIF-1 α、BDNF的水平,海马组织行HE染色、尼氏染色观察海马各亚区神经元细胞形态学变化,电镜观察海马CA1区神经元超微结构。结果:1.大鼠生长发育NC组大鼠精神状况良好,毛发光亮,行动自如,反应敏捷。CSH组和CIH组大鼠消瘦,精神萎靡,嗜睡,毛发无光泽或稀疏,行动迟缓,反应迟钝。NC组体重[(218.63± 15.287)g]明显高于 CIH 组[(195.75±6.497)g]和 CSH 组[(180.88 ± 12.017)g]体重,P0.05。2.Morris水迷宫实验2.1定位航行实验4天训练中,三组间不同时间点逃避潜伏期有显著差异(F=64.18,P0.05),CIH组和CSH组不同时间点逃避潜伏期有显著差异(P0.05)。NC组、CIH组、CSH组逃避潜伏期随着训练时间和次数的增加逐渐缩短(F=54.355,P0.05;F=109.809,P0,05;F=272.514,P0.05)。训练第1、2天,三组间逃避潜伏期有显著差异(F=19.248,P0.05;F=5.021,P0.05);第3天、4天,三组间逃避潜伏期差距逐渐缩短,无显著差异(P=0.706,P0.05;F=0.219,P0.05)。2.2空间探索实验三组间穿越平台的次数有显著差异(F=8.913,P0.05),组间两两对比,CIH组和CSH组之间差异无统计学意义(P0.05)。3.血清中HIF-1α、BDNF水平表达三组间HIF-1α、BDNF表达有显著差异(F=19.524,P0.05;F=8.552,P0.05),CIH组和CSH组HIF-1 α、BDNF表达显著高于NC组(P0.05),且CIH组HIF-1 α、BDNF表达较CSH组升高(P0.05)。三组间HIF-1 α、BDNF分别做相关性分析,均无明显相关性(P0.05)。4.海马神经细胞形态学变化4.1 HE染色NC组海马CA1区细胞带完整,细胞排列整齐紧密,形态规则,细胞核清晰;CSH组和CIH组细胞排列分散、紊乱,少量胞核固缩、胞质深染的早期坏死样改变。CIH组细胞带部分脱失,活细胞数量下降。4.2尼氏染色CA1区NC组海马细胞排列紧密,细胞核清晰,有丰富的细颗粒或斑块样尼氏体;CIH组锥体细胞排列散乱、数目减少,在Ⅰ和Ⅳ层均有细胞坏死。CSH组锥体细胞排列紊乱,细胞肿胀、空泡样变,少量坏死细胞。CIH组和CSH组均有部分尼氏体溶解、减少或者消失。细胞计数示,CIH组和CSH组阳性细胞数少于NC组(F=321.25,P0.05),组间对比,CIH组阳性细胞数少于CSH组(P0.05)。CA3区NC组海马锥体细胞排列紧密,结构清晰,尼氏体丰富;CIH组和CSH组均锥体细胞带中断,细胞排列紊乱,Ⅱ层出现细胞空泡样改变和少量坏死细胞。CIH组和CSH组尼氏体有不同程度溶解、减少。DG区NC组海马颗粒细胞排列紧密,结构清晰,尼氏体丰富;CIH组活细胞数量广泛下降,坏死细胞集中出现在Ⅱ和Ⅲ层。CSH组活细胞数量减少,在齿状回尾部,Ⅱ层出现大量细胞质深染,核消失的坏死细胞。4.3透射电镜检查NC组海马CA1区神经元胞核呈圆形或椭圆形,核膜清晰完整,常染色质分布均匀,细胞器丰富,结构形态清晰。CIH组海马神经元细胞核圆形,染色质边集,内质网不清晰,线粒体肿胀、嵴断裂,细胞器减少。CSH组海马神经元细胞变形,线粒体和内质网部分破坏,细胞器显著减少。结论:慢性缺氧抑制大鼠生长发育,使幼龄大鼠学习记忆认知功能下降;HIF-1 α参与神经系统缺氧应答,BDNF水平代偿性增加可能参与神经元细胞损伤调节,两者可能独立参与维持神经认知功能;而CIH高水平的HIF-1 α和BDNF提示机体可能处于持续缺氧应激状态。CIH独有的缺氧模式对海马神经细胞损伤程度更重,出现更严重认知功能障碍,海马不同亚区(CA1、CA3、DG)对缺氧损伤敏感度不同,神经元细胞损伤程度不同;CIH海马CA1区对缺氧损伤更敏感,出现显著的认知障碍。
[Abstract]:Objective: To explore the effects of different hypoxia methods on the expression of HIF-1 alpha, BDNF and hippocampal morphology and cognitive function of young Wistar rats, and to explore the possible mechanism of related mechanisms by establishing a young rat model of chronic intermittent hypoxia and chronic persistent hypoxia. Methods: 24 male Wistar rats of (20 + 2) days of age were selected. The random digital table method was divided into 3 groups: group NC, group CIH and group.NC in group CSH, CIH group intermittent hypoxia 8h every day, CSH group continuous hypoxia 8h every day, two groups of rats for 30 days. After completing the model, the body weight of the rats was recorded, the growth and development of the rats were recorded, the learning and memory ability of the rats was detected by the Morris water maze, ELISA tested HIF-1 alpha in serum ELISA. BD The level of NF, hippocampal tissue HE staining, Nishi staining observed the morphological changes of neurons in the hippocampus and the ultrastructure of hippocampal neurons in the hippocampus CA1 area. Results: the 1. rats grew and developed NC rats with good mental condition, bright hair and action, reaction to agile.CSH group and CIH group of rats, lethargy, lethargy, hairs and hair. Lustre or sparsity, slow action, and slow reaction.NC group weight [(218.63 + 15.287) g] significantly higher than group CIH [(195.75 + 6.497) g] and CSH Group [(180.88 + 12.017) g] weight, P0.05.2.Morris water maze experiment 2.1 navigation Experiment 4 days training, three groups at different time points escape latency has significant difference (F=64.18, P0.05), CIH and CSH groups There were significant differences in the escape latency at different time points (P0.05), group CIH, group CIH, and the escape latency of group CSH gradually shortened with the increase of training time and number of times (F=54.355, P0.05; F=109.809, P0,05; F=272.514, P0.05). Training for 1,2 days, there were significant differences between the three groups of escape latency (F=19.248, 4 days, three escape). There was no significant difference (P=0.706, P0.05; F=0.219, P0.05).2.2 space exploration experiment between three groups, there were significant differences (F=8.913, P0.05), and between group 22, CIH group and CSH group had no statistical significance (P0.05).3. serum HIF-1 alpha in three groups. The differences (F=19.524, P0.05, F=8.552, P0.05), HIF-1 alpha and BDNF in group CIH and CSH group were significantly higher than that in group NC (P0.05), and CIH group HIF-1 alpha. The cells arranged neatly closely, the morphology was regular, the nucleus was clear, the cells in group CSH and CIH were arranged and dispersed, the cells were in disorder, a small number of nuclei were fixed, the early necrotic samples of the cytoplasm were changed in.CIH group, the number of living cells decreased and the number of living cells decreased by.4.2 Nissl staining CA1 region NC group, the hippocampus cells were closely arranged, the nuclei were clear, and there were rich fine particles or spots. The pyramidal cells in the CIH group were arranged and scattered, the number of pyramidal cells was reduced. The pyramidal cells in group.CSH of group I and IV were disorganized, the cells were swollen, and the vacuoles were changed. Some of the.CIH and CSH groups of necrotic cells were dissolved, reduced or disappeared. The number of cells in the CIH and CSH group was less than that of the NC group (F=321.25,) P0.05), the number of positive cells in group CIH was less than that of group CSH (P0.05) in group.CA3 (P0.05), the pyramidal cells in the hippocampal pyramidal cells were closely arranged, the structure was clear and the Nissl body was rich; the pyramidal cell bands of the CIH group and the CSH group were interrupted, the cell arrangement was disorganized, the cell vacuoles like changes in the second layer and the small number of necrotic cells and the CSH group Nissl bodies were dissolved in varying degrees and decreased. The hippocampal granulosa cells in group DG NC were arranged closely, the structure was clear and the Nissl body was rich. The number of living cells in group CIH decreased widely. The necrotic cells concentrated in the number of living cells in group II and III.CSH group, at the tail of dentate gyrus, and there was a lot of cytoplasmic deep staining in the dentate gyrus, and the bad dead cells of the nucleus disappeared in the NC group CA1 region neurons by.4.3 transmission electron microscope. The nucleus is round or oval, the nuclear membrane is clear and complete, the chromatin is evenly distributed, the organelle is rich and the structure shape is clear. The nucleus of the hippocampal neurons is round, the chromatin is set, the endoplasmic reticulum is not clear, the mitochondria swollen, the crista breaks, the organelle reduces the deformation of the hippocampal deity in the.CSH group, the mitochondria and endoplasmic reticulum are partially destroyed and the organelles are destroyed. Conclusion: chronic hypoxia inhibits the growth and development of rats and reduces the cognitive function of learning and memory in young rats; HIF-1 alpha participates in the hypoxia response of the nervous system, and the compensatory increase of BDNF may participate in the regulation of neuronal cell damage. Both of them may participate in the maintenance of neuro recognition function independently; and CIH high level HIF-1 alpha and BDNF prompting machine The hypoxic mode of.CIH, which may be in the state of persistent hypoxia stress, has more severe impairment of hippocampal neurons, more serious cognitive impairment, different hippocampal subregions (CA1, CA3, DG) are sensitive to hypoxia injury, and the damage degree of neuron cells is different. CIH sea horse CA1 area is more sensitive to hypoxia injury, and a significant cognitive impairment appears. Hindering.

【学位授予单位】：广州中医药大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R766

【相似文献】