干酪乳杆菌对抑郁大鼠行为学和神经系统及肠道菌群影响的研究

发布时间：2018-05-26 13:23

本文选题：抑郁大鼠 + 行为学　；参考：《青岛大学》2017年硕士论文

【摘要】：目的:初步研究干酪乳杆菌(Lactobacillus casei)对抑郁大鼠行为、神经系统及肠道菌群的影响。方法:适应性喂养后按体重,将大鼠随机分为5组,分别是空白对照组(A),模型组(B),阳性对照组(C),干酪乳杆菌干预剂量I组(D)和干预剂量II组(E)组。除A组外,对其余各组在整个实验中采用CUMS结合孤养建立大鼠抑郁模型。建模三周后采用灌胃的方法进行干预,D、E组分别给予干酪乳杆菌4×108 CFU/kg/d和8×108 CFU/kg/d,C组给予帕罗西汀1.8 mg/kg/d,A组和B组给予等量的生理盐水(1.8 mg/kg/d),干预时间为四周。采用旷场实验、糖水消耗实验、24 h食物消耗实验及记录体重变化,观察大鼠行为学变化。干预结束后大鼠禁食不禁水12 h,注射3%戊巴比妥钠麻醉,低温下迅速分离大脑前额叶皮质,解剖留取盲肠内容物,通过HPLC-ECD检测皮质中多巴胺(DA)、去甲肾上腺素(NE)和5-羟色胺(5-HT)的浓度,Western Blotting检测脑源性神经营养因子(BDNF)、p38MAPK和p ERK1/2蛋白的表达,RT-PCR检测酪氨酸激酶受体B(Trk B)受体和N-甲基-D-天冬氨酸受体(NMDA)受体的NR1亚基的m RNA表达,RT-PCR检测盲肠内容物中粪肠球菌(Enterococcus faecalis)、双歧杆菌属(Bifidobacterium)、乳酸菌(Lactobacillus)和大肠杆菌(Escherichia coli)四种菌在各组间的差异。结果:在应激下,大鼠表现出抑郁样行为,糖水偏爱百分比、移动速率和距离B组较A组分别降低24.6%、37.6%和23.1%。干酪乳杆菌干预后大鼠的抑郁行为明显改善,表现为糖水偏爱百分比在C、D、E组较B组分别显著增加20.5%、15.9%、16.0%,差别有显著性(P0.05);在旷场中的移动速率和移动距离均较B组均显著增加(P0.05);从第四周开始,B组较A组和各干预组体重增长缓慢(P0.05),而食物消耗量在各组间未见明显差异;CUMS使得大鼠前额叶皮质中Trk B受体和NR1亚基的m RNA表达、BDNF蛋白表达及血浆DA、NE和5-HT的浓度显著降低(P0.05),而干预后这一情况得到改善,其中与B组相比D、E组BDNF分别增加40.9%和42.9%,DA、NE、5-HT分别增加15.8%、15.5%、11.2%和20.5%、19.7%、11.7%。在CUMS暴露下大鼠前额叶皮质中p38MAPK和p ERK1/2的蛋白表达水平显著增加,即B组与A组相比,p38MAPK和p ERK1/2分别增加122%、65.7%和147%,而干预后能显著逆转这些变化,D、E组较B组分别降低23.2%、24.6%、46.9%和28.7%、29.7%、46.9%(P0.05)。应激下B组与A组相比乳酸菌、粪肠球菌和大肠杆菌均显著增加,差异均有统计学意义(P0.05),双歧杆菌呈下降趋势,但未见显著性差异。干预后与B组相比乳酸菌、粪肠球菌和大肠杆菌在C、D、E组均显著降低,差异均有统计学意义(P0.05),而双歧杆菌呈上升趋势,未见统计学差异。结论:在应激下,大鼠表现出明显的抑郁样行为,而干酪乳杆菌能够改善抑郁样行为,影响大鼠神经系统,调节抑郁大鼠的肠道菌群,为抑郁症的相关研究提供新的视角。
[Abstract]:Aim: to study the effects of Lactobacillus caseii on behavior, nervous system and intestinal flora in depressed rats. Methods: after adaptive feeding, rats were randomly divided into 5 groups according to their body weight. The rats were divided into 5 groups: blank control group, model group, positive control group, Lactobacillus casei intervention dose group I (D) and intervention dose group II (E) group. With the exception of group A, the depression model of rats was established by CUMS combined with solitude in the whole experiment. After three weeks of modeling, the rats in group E were treated with Lactobacillus casei 4 脳 10 ~ 8 CFU/kg/d and group C 8 脳 10 ~ 8 CFU / kg 路kg ~ (-1) 路d ~ (-1) respectively. Paroxetine 1.8 mg 路kg ~ (-1) 路d ~ (-1) of normal saline was given to group A and B for four weeks. Open field experiment, sugar water consumption test, food consumption test for 24 h and body weight change were used to observe the behavioral changes of rats. Rats fasting for 12 hours were anesthetized with 3% pentobarbital sodium. The prefrontal cortex was quickly separated under hypothermia and the caecum contents were dissected. The expression of BDNF p38 MAPK and p ERK1/2 protein in brain derived neurotrophic factor (BDNF) was detected by HPLC-ECD. The tyrosine kinase receptor (B(Trk B) receptor and N- methyl-D- (-) -day receptor were detected by reverse transcription-polymerase chain reaction (RT-PCR). The m RNA expression of NR1 subunit of aspartic acid receptor (NMDA) receptor was detected by reverse transcription-polymerase chain reaction (RT-PCR). Enterococcus faecalisus, Bifidobacterium, Lactobacillus (Lactobacillus) and Escherichia coli (Escherichia coli) in cecum contents were detected by reverse transcription-polymerase chain reaction (RT-PCR). Results: under stress, rats showed depressive behavior, percentage of sugar water preference, moving rate and distance of group B decreased 24.637.6% and 23.1g than those of group A, respectively. After Lactobacillus casei intervention, the depressive behavior of rats was significantly improved. The results showed that the percentage of preference for sugar water in group C DU E was significantly higher than that in group B (20. 5%, P 0. 05%, P 0. 05), and that in group B was significantly higher than that in group B (P 0. 05), and from the fourth week onwards, group B was significantly higher than group A and the intervention group in terms of moving distance and velocity (P 0. 05%, P 0. 05%, P 0. 05%, P 0. 05%, P 0. 05%, P 0. 05%, respectively). There was no significant difference in food consumption among the three groups. The expression of m RNA of Trk B receptor and NR1 subunit in the prefrontal cortex of rats and the concentration of DANE and 5-HT in plasma decreased significantly in the prefrontal cortex of rats, but after intervention, the expression of m RNA in the prefrontal cortex of rats was significantly decreased. The situation has improved, Compared with group B, the BDNF of group D and E increased by 40.9% and 42.9%, respectively. The expression of p38MAPK and p ERK1/2 in prefrontal cortex of rats exposed to CUMS was significantly increased, that is to say, compared with group A, the levels of p38 MAPK and p ERK1/2 in group B were increased by 122. 7% and 14. 7%, respectively. After intervention, these changes were significantly reversed by 23. 224.646. 9% and 28. 729. 729. 7%, respectively. Under stress, lactic acid bacteria, Enterococcus faecalis and Escherichia coli in group B were significantly higher than those in group A, and the difference was statistically significant (P 0.05). Bifidobacterium showed a downward trend, but there was no significant difference. Compared with group B, lactic acid bacteria, Enterococcus faecalis and Escherichia coli decreased significantly in group C (P 0.05), but Bifidobacterium showed an increasing trend, but there was no statistical difference. Conclusion: under stress, rats showed depressive behavior, while Lactobacillus casei could improve depression-like behavior, affect nervous system, regulate intestinal flora of depressed rats, and provide a new perspective for the study of depression.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R749.4

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