A Preliminary Study Of The Molecular Mechanisms Of Hyperglycemia Aggravate The Post-stroke Epilepsy After Cerebral Ischemia

Objective To study whether hyperglycemia can aggravate the post-stroke epilepsy after cerebral ischemic and the effects of hyperglycemia on brain tissue injury of post-stroeepilepsy rat;explore the the molecular mechanisms of hyperglycemia aggravate the post-stroke epilepsy after cerebral ischemia.Material and Methods Healthy male SD rats were provided by the Experimental Animal Center of Ningxia Medical University,weighing 220 ~ 250 g, reared in a quiet environment,given plenty of clean water and food.Classify the SD male rats into 4 groups randomly:the control,the blank,the hyperglycemia,the cerebral ischemia and the hyperglycemia﹢cerebral ischemia,n = 10 in each group;(1)the control group was detached bilateral common carotid artery(CCA),not to ligate the wagus nerve;(2)the blank received no processing;(3) the hyperglycemia group established by intraperitoneal injection of STZ;(4)the cerebral ischemia group established by ligating bilateral CCA and pressing low blood pressur(2VO);(5)the hyperglycemia﹢cerebral ischemia group established by intraperitoneal injection of STZ first,four weeks later, ligating bilateral CCA and pressing low blood pressur(2VO).After the experiment,some rats were decapitated, stripped of hippocampal tissue cryopreservation; another part of the rat in vivo perfusion line embedded in paraffin. Through injury of hippocampal neurons in rats TUNNEL staining and the EEG variance by wireless EEG;By immunohistochemistrya and Western Blot for m TOR and p-m TOR protein semi-quantitative and quantitative detection of brain regions and expression;q PCR to detect hippocampal m TOR m RNA. Application of statistical software for data analysis. Experimental data expressed as mean±standard deviation,data using single-factor analysis of variance between groups after the homogeneity of variance test was used to compare the difference was statistically significant LSD-t test,with p ≤ 0.05 was considered statistically significant.Results1.Model Establishment and the survival: After injected by STZ.nine of ten in the Hyperglycemia come to the requirements(blood sugar concentration>12mmol/l),The blo od sugar concentration of Epilepsy group all meet the requirements.Conventional breedi ng after 4 weeks,Cerebral-ischemia model on the basement of Epilepsy came out the r esults that one death and 8 rats appeared epilepsy seizure.Cerebral-ischemia model ha d one death and one appeared epilepsy seizure.2.Behavior of the models:The hyperglycemia rats had grand mal epilepsy after 10 hours’ cerebral ischemia.At the beginning,the rats behaved as follows:bear shrinking,facial spasm,eye locked tightly,drooling,chewed regularly.Shortly after that,they appeared a whole body shaking,choking,stand backward and dumping,the serious one running around the cage and even jumping.3.The monitoring of EEG:Abnormal EEG showed in the cerebral ischemia group,while the hyperglycemia ﹢ cerebral ischemia group appeared the paroxysmal high amplitude waveforms, and have the peculiar unique epilepsy wave spines- slow wave and multiphase spike wave waveform, and frequent multiple spike wave,which is the classical epilepsy waveforms.4.TUNEL:The numbers of positive cells in the Control,Blank,Hyperglycemia,Cerebr al-ischemia,and hyperglycemia﹢cerebral ischemia groups:9.0±0.82,6.0±0.81,19.7±1.24,24.7±1.69,41.3±1.70.The difference was statistically significant in hyperglycemia﹢cerebral ischemia and Hyperglycemia,Cerebral-ischemia group(p<0.01),in Cerebral-ischemia and Control,Blank,Hyperglycemia(p<0.05),and also in Hyperglycemia and Control,Blank(p<0.01).However,there is no statistical significance in Control and Blank(p<0.05).It shows t hat hyperglycemia can not only cause damage of the normal neurons in rats,but also a ggravate the damage of the hippocampus neurons in cerebral-ischemia rats.5.IHC:If the neuronal cytoplasm showed tan,it is positive.The positive cell’s numb ers of the expression of p-m TOR in Control,Blank,Hyperglycemia,Cerebral-ischemia, hy perglycemia﹢cerebral ischemia group:19.33±1.25, 15.67±1.24,51.33±2.87,44.33±1.69,31.33±1.26.The difference of the expression of p-m TOR between Hyperglycemia,Cerebral-is chemia, hyperglycemia﹢cerebral ischemia group and Control,Blank were statistically si gnificant(p<0.01).But the expression of p-m TOR in hyperglycemia﹢cerebral ischemia is lower than Hyperglycemia and Cerebral-ischemia(p<0.05);There is no statistical signi ficance between Control and Blank in the expression of p-m TOR(p<0.05).And it predi cts the signal pathway of m TOR is not the cause that hyperglycemia can promotes po st-stroke epilepsy after cerebral ischemic.6. Western-Blot:Using Gel-Pro analyzer Gel imaging analysis software to calculate each groups’ relative grey value.The relative grey value of p-m TOR/m TOR in Contro l,Blank,Hyperglycemia,Cerebral-ischemia and hyperglycemia﹢cerebral ischemia group is:41±0.05,0.55±0.06,1.43±0.09,1.16±0.08,0.93±0.08(p<0.01). Conclusion Hyperglycemia can aggravate the damage of the brain tissue after cerebra l-ischemia and enhance the incidence of epilepsy vastly;the expression of p-m TOR imp roves significantly in Hyperglycemia,Cerebral-ischemia and hyperglycemia﹢cerebral isc hemia,but the Epilepsy group is lower than Hyperglycemia and Cerebral-ischemia.It is deduced preliminary that the signal pathway of m TOR is not the cause that hypergly cemia can promotes post-stroke epilepsy after cerebral ischemic.