Cognition Dysfunction And The Expression Of TGF-β₁,Bcl-2,MDA,SOD With Chronic Cerebral Ischemia And Study On Therapeutic Efficacy Of Edaravone

Objective To explore the spatial memory ability and dynamic changes and interrelation of TGF-β1,Bcl-2,MDA,SOD expression in the cortex of frontal lobe and hippocampus region of rats with chronic cerebral ischemia. Rats with chronic cerebral ischmia were treated with edaravone and cerebrolysin vial by intraperitoneal injection to observe the changes of spatial memory ability and TGF-β1,Bcl-2,MDA,SODexpression.To provide theory base for clinical therapy of vascular dementia.Methods We choosed healthy male Wistar rats and adopted the long-term ligation of bilateral common carotid arteries to produce the chronic cerebral ischemia model of rats that was similar to the human chronic cerebral ischemia. Rats were received edaravone(10mg/kg) and cerebrolysin vial(5ml/kg) by intraperitoneal injection, one time everyday from 3 weeks post-operation until to put to death. We evaluated the stroke exponent and neurology symptoms of rats at 1d,3d,7d,14d,28d after operation. We estimated the spatial memory ability of the rats by the Y labyrinth test at 2w,4w,8w,12w,16w after operation. We adopted HE staining and light microscope to observe morphology cganges of brain constitution; We adopted immunohistochemistry and actinic chemistry colorimetry to detect the expression of TGF-β1,Bcl-2 and SOD,MDA in the cortex of frontal lobe and hippocampus region. We adopted SPSS12.0 software to carry out statistics analysis. Firstly,tests for normal distribution and homogeneity of variance were carried out. One-way variance analysis and q test were adopted to compare.Results1.Cognition function changes of rats with chronic cerebral ischemia..The stroke exponent and neurology symptoms exponent assembled to the normal at 3d after ligation and no motor dysfunction was observed. The rats'performance in Y labyrinth test showed their memory ability at 2week after operation. There was obvious individual difference in the rats'memory ability in Ylabyrinth test at 2 week after ligation and some rats'memory ability decreased obviously.The rats'memory ability decreased significantly at 4 week after ligation compared with control group,P<0.01, The decrease was more apparent when ischemia continued and the decrease reached the peak at 4 month after operation. The right number of times in Y labyrinth test increased more significantky in cerebrolysin vial group and edaravone group than in ischemia group,P<0.01.The right numeber of times in Y labyrinth test were more significantly in edaravone group than that in cerebrolysin vial group,P<0.01.2. Histopathology changes:The form and distribution of the nerve cells in the cortex of frontal lobe and hippocampus region of the rats in control group.From 4 week, two rats had infarcts in scattered regions,such as caudate nucleus, frontal cortex, and corpus callosum. The degeneration, necrosis and detachment of neuron could be seen, so did the hypertrophic neuroglial proliferation in the cortex of frontal lobe and hippocampus region, No evident infarct was visible agter 8 weeks. The degeneration and necrosis of the neurons lessened, as well as the hypertrophy of the neuroglial cells. The detachment got fradually worse.The cerebral ventricle and atrophic cortex could be seen.The degeneration,necrosis and detachment of neuron and neuroglial proliferation decreased significantly in edaravone group and in cerebrolysin vial group than that in ischemia group.3. The expression of TGF-β1,Bcl-2,MDA,SOD in the cortex of frontal lobe and hippocampus region.There was mild TGF-β1expression in the cortex of frontal lobe and hippocampus region of rats in control group. The expression of TGF-β1in the cortex of frontal lobe and hippocampus region in ischemia group significant increased in 4 week after ligation, and decreased gradually after 4weeks.The expression of TGF-β1in the cortex of frontal lobe in ischemia group was still higher than that in contral group at 12 week after ligation,P<0.05.The expression of TGF-β1 in the hippocampus region in ischemia group was still higher than that in control group at 8 week after ligation,P<0.05. The expression of TGF-β1 in the cortex of frontal lobe and the hippocampus region in edaravone group and in cerebrolysin vial group was significantly higher than that in ischemia group,P<0.01. The expression of TGF-β1in the cortex of frontal lobe and the hippocampus region in edaravone group was significantly higher than that in cerebrolysin vial group,P<0.05.There was mild Bcl-2 expression in the cortex of frontal lobe and hippocampus region of rats in control group. The expression of Bcl-2 in the cortex of frontal lobe and hippocampus region in ischemia group significant increased in 4 week after ligation, and decreased gradually after 4 weeks. The expression of Bcl-2 in the cortex of trontal lobe in ischmia group was still higher than that in control group at 12week after ligation,P<0.05. The expression of Bcl-2 in the hippocampus region in ischemia group was still higher than that in control group at 4 week after ligation,P<0.01. The expression of Bcl-2 in the cortex of frontal lobe and the hippocampus trgion in edaravone group and cerebrolysin vial group was significantly higher than that in ischemia group,P<0.01.The expression of Bcl-2 in the cortex of frontal lobe and the hippocampus region in edaravone group was significantly higher than that in cerebrolysin vial group,P<0.05.There was mild MDA expression in the cortex of frontal lobe and hippocampus region of rats in control group. The expression of MDA in the cortex of frontal lobe and hippocampus region in ischemia group significant increased in 4 week after ligation, and decreased gradually after 4 weeks. The expression of MDA reached the normal at 12weeks in every group. The expression of MDA in the cortex of frontal lobe was significantly higher than that in control group at 8weeks after ligation,P<0.01. The expression of MDA in the cortex of frontal lobe and the hippocampus region in edaravone group and cerebrolysin vial group was higher than that in control group,P<0.05. The expression of MDA in the cortex of frontal lobe and the hippocampus region in edaravone group and cerebrolysin vial group was higher than that in ischemia group,P<0.01. The expression of MDA in the cortex of frontal lobe and the hippocampus region in edaravone group was higher than that in cerebrolysin vial group, P<0.01 (at 4 weeks after ligation).P<0.05(at 8 weeks after ligation).There was mild SOD expression in the cortex of frontal lobe and hippocampus region of rats in control group. The expression of SOD in the cortex of frontal lobe and hippocampus region in ischemia group significant decreased in 4 week after ligation, and increased gradually later. The expression of SOD reached the normal basically at 12 weeks in every group. The expression of SOD in the cortex of frontal lobe and hippocampus region was significantly higher than that in control group at 12weeks after ligation,P<0.01. The expression of SOD in the cortex of frontal lobe and the hippocampus region in edaravone group compared with control group at 12 Weeks after ligation,P>0.05. The expression of SOD in the cortex of frontal lobe and the hippocampus region in cerebrolysin vial group compared with control group at 12 Weeks after ligation,P<0.05. The expression of SOD in the cortex of frontal lobe and the hippocampus region in edaravone group and cerebrolysin vial group was higher than that in ischemia group,P<0.01.The expression of SOD in the cortex of frontal lobe and the hippocampus region in edaravone group was higher than that in cerebro-lysin vial group,P<0.01,P<0.05.Conclusion:1. Cognition function of the rats with chronic cerebral ischemia by permanent occlusion of bilateral common carotid arteries decreased gradually.2. The rats with permanent occlusion of bilateral common carotid arteries showed gradually detachment of pyramidal cell and neuroglial proliferation in the cortex of frontal lobe. There are severe the pyramidal cell detachment,groud substance rarefaction and micro-vacuoles formation in hippocampus region.3. The rats with permanent occlusion of bilateral common carotid arteries showed gradually decreasing. in the SOD expression and increasing in the MDA expression and the expression of cytokine TGF-β1,Bcl-2 obviously. All these cytokine not only took part in the early apoptosis after permanent occlusion of bilateral common carotid arteries,but also contributed to the delayed neuron death. Facilitating the expression of Bcl-2 is the most important way to inhibit neuron apoptosis.4. Edaravone and cerebrolysin vial both ameliorated the cognition function of rats with chronic cerebral ischemia.Both of them can eliminate the free radical in valid and lessen the lost SOD,and facilitate the expression of TGF-β1,Bcl-2 in the cortex of frontal lobe and hippocampus region. The effect of edaravone was higher significantly than cerebrolysin vial.