【作者】 刘辉；

【导师】 涂生芬；

【作者基本信息】 重庆医科大学 ， 麻醉学， 2020， 硕士

【摘要】 目的:研究丙泊酚对未成年肥胖大鼠认知功能的影响,并探讨其相关机制。方法:取21日龄SD雄性大鼠140只随机分为基础饲料组(n=40)和高脂饲料组(n=100)。基础饲料组予以基础饲料喂养,高脂饲料组予以高脂饲料喂养。喂养4周后,取高脂饲料喂养组大鼠体重大于或等于基础饲料喂养组平均体重加1.4倍标准差的40只大鼠判定为肥胖建模成功。将基础饲料组大鼠随机分为正常脂肪乳组(NL)、正常丙泊酚组(NP),将建模成功的肥胖大鼠随机分为肥胖脂肪乳组(OL)、肥胖丙泊酚组(OP),每组20只。丙泊酚组腹腔注射丙泊酚100mg/kg,对照组腹腔注射脂肪乳剂(丙泊酚的溶剂,作为对照)10ml/kg,连续7天,一天注射一次。停药后第一天,各组大鼠行Morris水迷宫实验评估大鼠空间学习记忆能力。于停药后第一天,ELISA法检测各组大鼠血浆S100β蛋白含量,取海马组织用qPCR检测Notch1、Jagged1、HO-1、SOD1的mRNA表达水平;Western blot法检测Notch1、Jagged1、HO-1、SOD1蛋白表达,HE染色法观察海马神经元变化。结果:(1)基础饲料组和高脂饲料组初始体质量无明显差异,喂养三周后,高脂饲料组大鼠体质量显著高于基础饲料组(P<0.05),喂养第四周高脂饲料组大鼠体质量显著高于基础饲料组(P<0.01),符合肥胖标准的大鼠40只,肥胖建模成功率为40%。基础饲料组和高脂饲料组四周饲料消耗结果显示,高脂饲料组大鼠四周饲料消耗均显著低于基础饲料组(P<0.01)。(2)水迷宫结果显示:各组大鼠在第1~4天逃逸潜伏期均呈缩短的趋势,并于第4、5天趋于稳定。与OL组相比,OP组在第1~5天逃逸潜伏期均延长(P<0.05)。与NL组相比,NP组在第1、2两天逃逸潜伏期均延长(P<0.05)。与OL组相比,OP组的第三象限停留时间以及穿越平台次数均明显减少(P<0.05)。(3)酶联免疫吸附测定实验显示:与OL组相比,OP组S100β蛋白含量显著增高(P<0.05),NP组、NL组、OL组组间无显著差异。(4)qPCR结果:与OL组比较,OP组Notch1、Jagged1 mRNA表达降低(P<0.05),NP组与NL组之间无显著差异。与OL组比较,OP组HO-1、SOD1mRNA表达降低(P<0.05),NP组、NL组、OL组组间无显著差异。(5)Western blot结果:与OL组比较,OP组Notch1、Jagged1蛋白表达量降低(P<0.05),NP组、NL组、OL组组间无显著差异。与OL组比较,OP组HO-1、SOD1蛋白表达量降低(P<0.05),NP组、NL组、OL组组间无显著差异。(6)海马CA1区HE染色结果:与NL组、NP组、OL组相比,OP组海马CA1区HE染色显示神经细胞排列松散,且细胞数量显著减少(P<0.01)。NL组、NP组、OL组三组海马CA1区神经细胞形态正常且排列有序。结论:丙泊酚麻醉可较长时间损害未成年肥胖大鼠认知功能,其机制可能与Notch信号通路的抑制,导致HO-1、SOD1酶活性降低,进一步引起氧化-抗氧化失衡有关。更多还原

【Abstract】 Objective: To investigate the effects and mechanisms of propofol on cognitive function in young obesity rat.Methods: Four weeks-old male SD rats were randomly divided into two groups: normal diet group and high-fat diet group.The two groups were fed with a normal diet(ND)and a high-fat diet(HFD)for 4 weeks,respectively.Animals in high-fat diet group that were greater than chow control group mean body weight +1.4*Standard Deviation were designated as obesity rats,according to the method that others have previously used.Then,SD rats in each dietary group were divided into two subgroups : normal lipid emulsion solvent group(NL),normal propofol group(NP),obesity lipid emulsion solvent group(OL)and obesity propofol group(OP)(n=20),which were intraperiotoneally administered propofol(100mg/kg)or lipid emulsion solvent(10ml/kg)for 7 days.And then their behavioral performance in a Morris water maze was monitored to determine the cognition of spatial learning and memory.And the plasma S100β protein content of each group was detected by ELISA.The mRNA expression levels of Notch1、Jagged1、HO-1、SOD1 in the rat hippocampus were determined by qPCR.The protein expression levels of Notch1、Jagged1、HO-1、SOD1 in the rat hippocampus were determined by Western blot.And the changes of hippocampal neurons was observed by HE staining in the hippocampus of rat.Results:(1)There was no significant difference in the initial body weight between the normal diet group and the high-fat diet group.After three weeks of feeding,the body weight of the high-fat diet group was significantly higher than that of the normal diet group(P<0.05).After four weeks of feeding,the body weight of the high-fat diet group was significantly higher than that of the normal diet group(P<0.01),40 rats meet the obesity standard,the success rate of obesity modeling is 40%.The feed consumption results showed that the rats in the high-fat diet group was significantly lower than that of the normal diet group(P<0.01).(2)Rats in each group showed a shortening trend during escape latency on days 1-4 and stabilized on days 4 and 5.Compared with that of the OL group,the escape latency of the OP group was longer on days 1-5(P<0.05).Compared with that of the NP group,the escape latency of the NL group was shortened on days 1-2(P<0.05).Compared with those of the NP and OL groups,the OP group showed significantly reduced third quadrant residence time and platform-crossing times(P<0.05).(3)Result of ELISA showed: Compared with the OL group,the S100β protein content in the OP group was significantly increased(P<0.05),and there was no significant difference among NP group,NL group and OL group of the S100β protein content.(4)Results of mRNA showed: Compared with the OL group,the expression of Notch1 and Jagged1 mRNA in the OP group decreased(P<0.05),and there was no significant difference among NP group,NL group and OL group of the mRNA expression.Compared with the OL group,the expression of HO-1 and SOD1 mRNA in the OP group decreased(P<0.05),and there was no significant difference among NP group,NL group and OL group of the mRNA expression.(5)Results of Western blot showed: Compared with the OL group,the expression of Notch1 and Jagged1 protein in the OP group decreased(P<0.05),and there was no significant difference among NP group,NL group and OL group of the protein expression.Compared with the OL group,the expression of HO-1 and SOD1 proteins in the OP group decreased(P<0.05),and there was no significant difference among NP group,NL group and OL group of the protein expression.(6)Results of HE staining in hippocampal CA1 area showed: Compared with NL group,NP group,and OL group,OP group HE showed that nerve cells were loosely arranged and the number of cells was significantly reduced(P<0.01).The morphology of nerve cells in hippocampal CA1 area of NL group,NP group and OL group was normal and arranged in order.Conclusion: Propofol anesthesia can cause long-term impairment of cognitive function in young obese rats.The mechanism may be related to the inhibition of Notch signaling pathway,which leads to the decrease of HO-1 and SOD1 enzyme activities,causing oxidative-antioxidant imbalance.更多还原