颈交感神经阻滞对糖尿病大鼠海马P38、TLR4的影响

摘要

Aim:To observe the effects of cervical sympathetic ganglia block on expressions of P38 and TLR4 in hippocampus of diabetic rats.Methods:A total of 64 adult male rats were used in the study and a model of diabetes mellitus was established by using streptozotocin (STZ).The rats were divided into diabetes mellitus + cervical sympathetic ganglia block group (Group A,n =32) and diabetes mellitus group (Group B,n =32).Water maze test was used for positioned navigation and space exploration analyses.The cognitive function was observed before diabetes mellitus (T1),8 weeks (T2),10 weeks (T3) and 12 weeks (T4) after diabetes mellitus.Eight rats of each group were sacrificed at every time point for measuring expressions of P38 and TLR4 in hippocampus using Real-time RT-PCR and Western blot.Results:The latency was significantly extended and the platform-crossing ability lessened at 8 weeks,10 weeks and 12 weeks after diabetes mellitus when compared with those before diabetes mellitus (P ＜ 0.05).Compared with Group B,the escape latency was significantly shortened but the number of platform-crossing rats was remarkably increased in Group A (P ＜ 0.05).At each time point,Py38 protein expression in Group A was significantly higher than that in Group B,while TLR4 protein expression was significantly lower than that in Group B (P ＜ 0.05).The relative expression level of hippocampal P38mRNA in Group A was higher than that in Group B,while that of hippocampal TLR4mRNA was lower than Group B (P ＜ 0.05).Conclusion:Cervical sympathetic ganglia block can improve the cognitive function of diabetic rats through reducing the inflammation and P38 protein expression.%目的:观察颈交感神经阻滞对糖尿病大鼠海马P38蛋白及TLR4表达的影响.方法:雄性成年大鼠64只,采用链佐菌(STZ)制作糖尿病大鼠模型,分为2组.A组为糖尿病+颈交感神经阻滞组(n=32),B组为糖尿病组(n=32).水迷宫实验行定位航行实验及空间探索实验观察A、B组大鼠造模前(T1)、造模后8(T2)、10 (T3)、12(T4)周的认知功能.分别于各时点每组各处死8只大鼠,采用Real-time RT-PCR和Western blot法测定海马P38、TLR4的表达.结果:A、B组8、10、12周逃避潜伏期较造模前明显延长、穿越平台的次数明显减少(P＜0.05).与B组比较,A组(颈交感神经阻滞组)大鼠逃避潜伏期明显缩短、穿越平台的次数明显增加(Jp＜0.05).A组各时点海马P38蛋白相对表达量明显高于B组,海马TLR4蛋白相对表达量明显低于于B组(P＜0.05).A组各时点海马P38mRNA相对表达倍数明显高于B组,海马TLR4mRNA相对表达倍数明显低于B组(P＜0.05).结论:颈交感神经阻滞可改善糖尿病大鼠的认知功能,可能与其降低炎症反应、调节P38蛋白的表达有关.