The Effect Of Butylphthalide On Hippocampal Formation And A?1-42 Horizontal Zones Of Diabetes Mice

Objective: More and more people are concerned about cognitive dysfunction which is caused by diabetes.Synaptic of Hippocampus as basis neurobiological of learning and memory,it can directly affect cognitive function.At present we know that dementia includes vascular dementia and Alzheimer's disease.We should concern and research that whether dementia which is caused by type 2 diabetes is related with vascular factors and Alzheimer's disease.It has been shown that NBP as neuroprotective drugs can improve cognitive dysfunction,but the exact mechanism remains to be studied.The aim of this study is to observe that the effect of mice hippocampal synaptic plasticity,blood vessels and of A? after feeding the diabetic with NBP.Methods:1 Mice with diabetes were grouped8 6-week old male db/m mice were used as normal control group(NC,n = 8).16 db/db mice,were randomly divided into diabetic disease control group(DM,n = 8)and diabetic Ding phthalide group(DM-NBP,n = 8).2 Drug InterventionAfter raising animals a week,mice of DM-NBP group was fed with NBP which was dissolved in vegetable oil(the dose of NBP was 120mg/Kg/d),The mice of NC group and DM group were given the same amount of vegetable oil,once daily,continuous intervention for 6 weeks.3 General observationsThe body weight and the blood glucose of the mice were monitored once a week.General situations of mice were observed during the research,such as mental state,food intake,water intake,urine volume,etc.4 Behavioral testsAfter six weeks of drug intervention,these mice was in water maze test for 5 consecutive days for spatial training,at the sixth day for spatial probe test,the escape latency and the number of times of crossing the platform of mice were recorded in each group.5 Electron microscopy and Western-blot,PCR detectionAfter the water maze experiment,these mice were killed.The hippocampal tissue samples was prepared for electron microscope and observed the ultrastructure of hippocampus;Western blot and RT-PCR was applied to detect the expression levels of synaptophysin,VEGF and A?1-42.Result: 1 GenerallyThe mice of NC group:the mice were with good mental state,white and glossy fur.Their drinking,eating and urine were normal;the mice of DM and DM-NBP group: the mice were polyuria,polydipsia,polyphagia,depression irritability,sparse and lusterless fur,gain rapid growth.After 6 weeks of intervention,there were no significant differences in DM and DM-NBP group(P>0.05),but compared with the NC group,these two groups of blood glucose was significantly increased(P<0.05);the body weight of DM and DM-NBP group was significantly higher than NC group,it was statistically significant(P<0.05),there was no significant difference between DM group and DM-NBP group(P>0.05).2 Ethology2.1 Determination of basic swimming speedBefore the start of the experiment,excluding individual differences,each group of mice swam freely for 60 s.The basic swimming speed was gotten,the result showed that there was no significantly difference between DM and DM-NBP group(P>0.05).2.2 Spatial learning trainingAt the first day,there was no significant difference between each group(P>0.05).When after 2-5 days,the escape latency of DM group and DM-NBP group was significantly longer than the NC group(P<0.05),the escape latency of DM-NBP group was shorter than the DM group(P<0.05).2.3 Probe testThe number of crossing the platform : NC group> DM-NBP group> DM group(P<0.05).3 Electron microscopy 3.1 Pyramidal cellsIn NC group,the hippocampal pyramidal cells: the nucleus was large and round,the nuclear membrane was integrated,chromatin was distributed evenly;organelles was rich,mitochondria was numberous and densely arranged,a larger number of reticulum of rough endoplasmic was distributed regularly;On the contrary,the hippocampal pyramidal cells of DM,the chromatin marginated and granulated,the organelles decreased,the mitochondria was edema and shaped irregularly,it was visible crista break or disappeared;the rough endoplasmic reticulum lumen was expansion,and irregular distributed.The mice of DM-NBP group,pathological changes of hippocampus pyramidal cells was alleviated compared with DM group.3.2 SynapseThe mice of DC group,synaptic structure was clear,synaptic vesicle was obvious;The mice of DM group,the synaptic structure was blurred,synaptic cleft was disappeared,the mitochondria in the presynaptic components was swelling;The mice of DM-NBP group,the pathological changes of synaptic structure was alleviated compared with DM group.3.3 CapillaryThe mitochondria and the rough endoplasmic reticulum of DM group was significant swelling;the capillaries in the DM-NBP group was mitigated compared with DM group.4 Results of Western-blotAmong the three groups,the synaptophysin expression levels was: NC group> DM-NBP group> DM group(P<0.05);VEGF expression level was: DM-NBP group> DM group> NC group(P<0.05);A?1-42 expression level was: DM group> DM-NBP group> NC group(P<0.05).5 RT-PCR resultsAmong the three groups synaptophysin protein expression in the hippocampus: NC group> DM-NBP group> DM group(P<0.05);VEGF protein expression: DM-NBP group> DM group> NC group(P<0.05);A?1-42 protein expression: DM group> DM-NBP group> NC group(P<0.05).Conclusion:1 The learning and memory ability of 13 week-old db/db mice decreased significantly.The Pyramidal cells,Synapse and capillary are all pathological changed in hippocampus,the protein and mRNA expression of VEGF and A?1-42 increased,the expression of synaptophysin decreased.2 When use NBP for prevention,it can improve the learning and memory abilities of diabetic mice,reduce the pathological changes of hippocampus ultrastructure,increase the protein and m RNA expression of VEGF and synaptophysin and reduce A?1-42 levels.