The Effect And Mechanism Of Dexmedetomidine On Status Epilepticus Of Immature Rats

PART ? EFFECT OF DEXMEDETOMIDINE ON STATUS EPILEPTICUS OF IMMATURE RATObjective: To explore the influence of dexmedetomidine on pilocarpine-induced status epilepticus of immature ratMethods: 21 d SD rats were used in this research.The model rats were injected with pilocarpine intraperitoneally to induce the status epilepticus.After the models were successfully established,dexmedetomidine(0.2ug/g or 1ug/g)combined with or without diazepam were administered to intervene and terminate the seizure and observe the changes of behavior and EEG,convulsion control success rate and 24-hour survival rate in each group.Afterwards,rats were divided into the normal group,SE group and Dex group.the influence of dexmedetomidine on the negative emotional changes of the model rats was observed through open field test and elevated cross maze.The hippocampus was used to observe the pathological changes.Results:(1)Dex 0.2ug/g combined with diazepam can improve the convulsion performance of SE model rats,and significantly improve the convulsion control success rate and 24 h survival rate of SE model rats.(2)Dex 0.2ug/g combined with diazepam can effectively terminate multiple spinous waves in EEG of SE model rats,and the EEG recovery time is short.(3)Dexmedetomidine can improve negative emotional changes after SE.(4)Dexmedetomidine can improve the Pathological changes in hippocampus of SE rats.Conclusion: Dexmedetomidine has the anticonvulsant and neuroprotective effect on the pilocarpine-induced status epilepticus of immature rats which are improved the negative emotion after SEPART ? THE EFFECTS OF DEXMEDETOMIDINE ON STATUS EPILEPTICUS OF IMMATURE RATS BY METABONOMICS ANALYSIS.Objective: To analyze the influence of dexmedetomidine on the pilocarpine-induced status epilepticus of immature rats by untargeted metabolomics analysisMethods: The hippocampus from the normal group,model group and the dexmedetomidine group were subjected to full-spectrum analysis using HILIC UHPLC-Q-TOF MS technique,followed by peak extraction and metabolite identification using XCMS.Data were afterwards preprocessed by Pareto-scaling for multidimensional statistical analysis,including PCA and PLS-DA,unidimensional statistical analysis,included Student's t-test and variation multiple analysis.R software was used to draw volcanic maps.Finally,cluster analysis of differential metabolites and KEGG metabolic pathway analysis were carried out with relevant software.Results:(1)The system stability evaluation and various statistical methods were used to confirm the reliability of the raw data from original samples and the obtained data with significant difference.(2)Results of clustering analysis between model group and normal group showed obvious clustering,which proved that significant difference compounds were representative.While data of clustering analysis on Dex group was between normal group and model group.(3)Changes of metabolite with significant differences in the model group showed that the epileptic persistence model in this experiment was successful and consistent with the metabolite changes in patients with clinical epilepticus.(4)Dexmedetomidine administration in the model group can significantly recover the metabolites towards to the normal group,characterized by mediating changing of metabolites,such as inhibiting glutamate excitatory amino acid expression,and promoting metabolites related to antioxidant stress.(5)KEGG metabolic pathway analysis suggested that dexmedetomidine may be involved in the brain protective metabolic pathways such as FoxO,PI3K-Akt,m TOR,AMPK,cAMP and other signaling pathways.Conclusions:Dexmedetomidinehas anticonvulsant and nuroprotective effect on status epilepticus rats,potentially through mediating excitatory amino acids,anti-oxidative stress via metabolic pathways,such as FoxO,PI3K-Akt,m TOR,AMPK,cAMP,etc.PART ? TRPV1 CHANNEL PARTICIPATES IN THE NEUROPROTECTIVE EFFECT OF DEXMEDETOMIDINE ON STATUS EPILEPTICUS IN IMMATURE RATSObjective:To explore the mechanism of dexmedetomidine on oxidative stress,calcium overload,cell apoptosis involving TRPV1 channel in Pirocaine-induced immature SE model mice.Methods:A total of 120 rats were randomly divided into six groups: Nor group,Dex control group,SE group,SE+Dex group,SE+Dex+Cap group and SE+Cap group,and then were successfully modeled and intervened.Morris water maze test was performed after interventions for two weeks.Meanwhile,ELISA,flow cytometry and transmission electron microscope were used to detect the changes of MDA(malonaldehyde)and SOD(Superoxide Dismutase),ROS(Reactive oxygen species)level,concentration of Ca2+ and mitochondrial membrane potential,respectively.Tunel staining was used to investigate the cell apoptosis,and expression of TRPV1 and Caspase 3 were measured by immunohistochemistry and western blotting.Results:(1)After dexmedetomidine intervention,the latency of platform-seeking in SE model rats was shortened,the exploration time in the quadrant of the original platform was prolonged,the times of crossing the platform and the swimming distance were increased.Dexmedetomidine improved the cognitive and memory function of SE rats to some extent.(2)The level of ROS and MDA were decreased after SE rats being treated with dexmedetomidine,along with promotion of SOD.These results indicated that dexmedetomidine plays protective role through anti-oxidant stress to exert brain protective function.(3)After dexmedetomidine intervention in SE rats,the ultrastructure of CA1 region in SE rats,featured by organelles decreasing,mitochondrial swelling of hippocampal neurons was recovered to normal.The intracellular calcium level was significantly decreased and the mitochondrial membrane potential was increased.The cerebral protection of dexmedetomidine against SE was associated with inhibition of calcium overload and improvement of mitochondrial structure and function.(4)After dexmedetomidine intervention in the model rats,the apoptotic rate in the rat brain decreased,and the expression of the apoptosisrelated protein Caspase 3 was significantly decreased.The brain protective effect of dexmedetomidine on model rats is related to antiapoptosis.(5)Dexmedetomidine administration can down-regulate the expression of TRPV1 protein in brain of SE.While capsaicin partially blocked the cerebral protection induced by dexmedetomidine in SE rats.The cerebral protection of dexmedetomidine against SE model rats may be through inhibition of the TRPV1 channel.Conclusions: Dexmedetomidine has a neuroprotective effect on status epilepticus induced by pilocarpine in immature rats,and its mechanism may be related to anti-oxidative stress,inhibition of calcium overload and antiapoptosis via inhibiting the TRPV1 channel.