Evaluate The Effection Of NO Donator And Prosoma On Mice Cerebral Ischemical Reperfusion Injury Model By Astrocyte, NO And MDA

Background and PurposeStroke is the third leading cause of death in the world. Ischemic stroke represents the main cause of death and disability among elderly people1. Most stroke survivors are left with lifelong disability2. Ischemical reperfu- sion injury is the most important problem in cerebral ischemia treatment, effective intervention devices are lacking now.Nitric oxide (NO) is a kind of endothelium derived relaxing factor(EDRF), after cerebrovascular disease attack, NO possess many effects including anapetia significantly and extensively, inhibitting the adherence and aggregation of blood plaque, accommodating the cerebral blood flow (CBF).Clinically, most of cerebral ischemia due to middle cerebral artery occlusion(MCAO), so we made MCAO models of rats, and gave them NO precursor (L-Arginine,L-Arg)/ NOdonor (Nitroglycerine)respectively by means of interventional injection in arteria carotis interna , evaluated the degree of limbs paralysis and improvement by Longa score ,observed the change in pathobiology and the content of malonaldehyde(MDA) and NO in blood serum, evaluated their role in ischemical reperfusion injury, in order to set up a new therap- eutic method of ischemic brain damage.MethodsIn this study, we selected healthy male adult Sprague-Dawley rats as research objects. sixty-six mice were divided into four groups randomly: (I)sham-operated group(n=12), (II)MCAO model group (n=18); (III) Nitroglycerine group (n=18); (IV)L-Arg group (n=18). Every group was divided into two subgroups according to the different sacrificed time: 3hand 24 h after the reperfusion,. Each subgroup included six rats. All drugs were administered immediately after reperfu- sion by means of interventional injection ( Normal sodium 1.50ml/kg Nitroglycerine 0.06ml/kg L-Arg 0.12ml/kg). Neurological deficits were evaluated by behavioral tests. Infarct volume was assessed by TTC (2,3,5-triphenyl-tetrazolium chloride) staining(except groups at 3h). The brain sections including cerebral cortex and hippocampus were stained by Hematoxylin-Eosin(HE)and glial fibrillary acidic protein (GFAP) antibody, The content of Serum NO and MDA were also detected。Result1. Longa score: Neurological deficits of the rats from Nitroglycerine and L-Arg groups improved significantly compared with MCAO model group at 3h after reperfusion (P<0.025), at the same time,the score of these two groups were lower than Shame-opration group(P<0.025) , there was no significant difference among these groups at 24h after reperfusion(P>0.025).2 TTC dyeing and cerebral infarction stereometry: There is no significant ischemic area in rat's brain among all the groups at 3h after reperfusion. At 24h after reperfusion, the largest mean was the infarct volume of rats in MCAO model group (23.01±4.07), and it had minished significantly in Nitroglycerine group (8.00±0.98), Nitroglycerine group,L-Arg (10.49±1.16) groups are all lower than MCAO model group(P<0.05).3. Pathomorphology:(1) HE staining(the cortex of ischemic side): There was no significant lose of cell in any groups at the time point of 3h;At time point 24h,Compared with sham-operated group,cells in MCAO model group losed significantly, there were more cells in Nitroglycerine group and L-Arg groups.(2)GFAP immunohistochemistry staining(ischemic side):At 3h after reperfusion In CA3 subfield of the hippocampus, Compared with MCAO model group, the number of GFAP immunoreactivity positive cells in Nitroglycerine and L-Arg groups decreased significantly (P<0.01,P<0.01). In the Hilus subfield of the hippocampus , the positive cells in Nitroglycerine and L-Arg groups were less than MCAO model group (P<0.01,P<0.01). In cerebral cortex , the positive cells in Nitroglycerine and L-Arg groups were less than MCAO model group too (P<0.01,P<0.05).At 24h after reperfusion In CA3 subfield of the hippocampus, this kind of cells in Nitroglycerine and L-Arg groups were less than MCAO model group (P<0.01,P<0.01). In Hilus subfield of the hippocampus and cerebral cortex, the cells in Nitroglycerine and L-Arg groups were less than MCAO model group (P<0.01,P<0.01).4 The result of serum NO:At 3h after reperfusion The content of serum NO in Nitroglycerine and L-Arg groups increased significantly compare with Shame-operated group(P<0.01 P<0.01), the content in the two groups were higher than MCAO model group (P>0.05 P<0.05).At 24h after reperfusion The content of serum NO in Nitroglycerine and L-Arg groups were higher than Shame-operated group(P<0.01 P<0.01), The content of serum NO in L-Arg group was higher than MCAO model group(P<0.05), and There was no difference between Nitroglycerine group and MCAO model group(P>0.05).5 The result of serum MDA:At 3h after reperfusion The content of serum MDA in Nitroglycerine and L-Arg groups increased significantly compare with Shame-operated group (P<0.05,P<0.05), and also lower than MCAO model group (P<0.05, P<0.05),there was no difference among the two groups.At 24h after reperfusion The content of serum MDA in NitroglYcer- ine and L-Arg groups increased significantly compare with Shame-operated group (P<0.05,P<0.05),and also decreased significantly compare with MCAO model group(P<0.05,P<0.01).Conclusion1. Administration of L-Arg / Nitroglycerine by means of interventional injection can protect ischemical reperfusion injury.2. To stabilize the activation of astrocyte and lower serum MDA , and also lessen nerves damage is the potential mechanism of Nitroglycerine and L-Arg in cerebral ischemia-reperfusion.