| Epileptic brain damage (EBD) is a recurrent seizures which have not been effectively controlled or caused by status epilepticus. Prolonged or repeated seizures will have a serious impact to the brain, will lead to mental retardation and behavioral abnormalities among children, which has brought heavy financial burden to the whole society and family. At present, The mechanism of the epileptic brain damage is still not very clear, therefore, study the pathogenesis of epilepsy brain damage as a pressing issue.The pathogenesis of epilepsy brain damage include glial cells,calcium-ion channels, endoplasmic reticulum stress, but the study of the endoplasmic reticulum stress is little, endoplasmic reticulum locat in eukaryotic cells organelles which adjustable Ca2+concentration and responsible protein transportion any impact on Ca2+concentration lead to protein misfolding or transfer factors will lead to endoplasmic reticulum stress (ERS), lead to activation of abnormal genes and a series of intracellular signal transduction. Endoplasmic reticulum stress pathway is a novel apoptosis pathway.The relation between endoplasmic reticulum stress pathway and epileptic brain damage is important which overcome the worldwide problem of epilepsy and provides a new idea.Erythropoietin is a cerebral protective agent which express brain protection by anti-apoptosis and apoptosis of nerve cells.ObjectiveExperimental studies have confirmed that the main forms pathological of the epileptic brain damage is apoptosis.There are three signal transduction pathways regulate apoptosis, mitochondrial pathway, death receptor pathway and endoplasmic reticulum stress pathway. The endoplasmic reticulum stress as a new signal transduction pathway, which the relationship research between epilepsy brain injury is little. Erythropoietin has been shown a cerebral protective effect. But the mechanism of in the endoplasmic reticulum stress have not related news. To explore endoplasmic reticulum stress-related factors CHOP and Caspase-12expression in hippocampus and possible mechanism of brain protection by erythropoietin on their expression in epileptic brain rats induced by Lithium-Pilocarpine.Materials and methods1Experimental animals groupingOne hundred and twenty21-30day neonatal healthy,clear-class Sprague-Dawley rats, male or female,weighing50g-100g,they were randomly divided into control group, epilepsy group and intervention group, n=40in each group and by6h,24h,48h,72h is divided into four subgroups, each subgroup10(n=10)2Modeling and observation of behaviorModeling which have referenced literature, the rats were observed immediately after drug administration, continuous attack to IV or V or continuous30min is considered as status epilepticus, epileptic seizures in rats based on Racine6grade level (0-V) classification method. 3Specimen collection and preparationThe rats were at6h,24h,48h,72h,10%chloral hydrate intraperitoneal injection of anesthesia, thoracotomy exposed the heart, cut the right atrial appendage, and then link scalp acupuncture,0.9%normal saline infusion,4%paraformaldehyde fixed until the liver white, body stiffen up. After craniotomy to take the back of the head, paraformaldehyde fixed for24hours, make the coronal sections, HE staining and immunohistochemistry detection.4Index measurement(1) HE staining, observed the pathological changes of brain tissue under the optical microscope.(2) The analysis of each group slices using Biosen Analysis system. Each slice are taken the five fields (×400).In the system, CHOP and caspase-12are measured with integrated optical density (IOD). The IOD are measured within each pixel optical density, IOD value of the positive product size and dye depth plot the IOD value, the stronger IOD,the greater the positive products of expression.5Statistical analysisThe SPSS17.0software comparison, more groups were compared using ANOVA, pairwise comparison between groups using LSD method.All of the datas would be described by mean±standeard, α=0.05is the significant level,P value less than0.05indicate statistical significance.Result1HE staining in rat brainHigh optical microscope, the normal control group, The morphology of normal cell in hippocampus, neat, clear nucleus, abundant cytoplasm, membrane integrity, prominent nucleoli. The hippocampus cell of epileptic rat disorder, cell morphology is not complete, some swelling, rupture and the residual shrinkage of neurons, the cytoplasm loose, ill-defined cell contours, disordered, dentate gyrus granule cells, irregular border.The nerve cells damage of the intervention group is little, hippocampal neuron loss is not obvious, less necrosis, degeneration, cell structure is more complete, arranged in a relatively neat. The number of surviving neurons in hippocampus more larger, clear nucleus, the majority of relatively normal cell morphology.2Immunohistochemical resultsThe expression of CHOP in hippocampus developed in epilepsy group increased gradually than that in control group at the same time points (P<0.05). There were statistically significant difference. The expression of CHOP in hippocampus developed in intervention group increased gradually than that in epilepsy group at the same time points (P<0.05). There were statistically significant difference. The expression of Caspase-12in hippocampus developed in epilepsy group increased gradually than that in control group at the same time points (P<0.05), reached peak in48h. There were statistically significant difference. The expression of Caspase-12in hippocampus developed in intervention group increased gradually than that in epilepsy group at the same time points (P<0.05). There were statistically significant difference.Conclusion1After epileptic brain damage, the expression of the CHOP and Caspase-12in hippocampus are significantly increased, suggest that they play an important role in the epilepsy brain injury2Erythropoietin play a role in brain protection through reduce endoplasmic reticulum stress mechanisms... |
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