| Objective:In this study, the middle cerebral artery occlusion (MCAO) model of rats was established following the modified suture method. The recombinant human granulocyte-colony stimulating factor(rhG-CSF) was injected into abdominal cavity, To explore the homing and repair of mobilizing bone marrow stem cell (BMSC)Method:54healthy ripe male Wistar rats were divided randomly into the rhG-CSF experiment group and the model group (each n=18). In addition, sham operation group were18rats too. The weight of them were220～260g. The right middle cerebral artery occlusion (MCAO) model were constituted by line block to induce cerebral infarction in experiment group and model group. When the rats were awake, Zeal Longa’s neurological behavioral assessments were performed. The rhG-CSF experiment group received daily abdominal cavity injection of rhG-CSF10μg·kg-1·d-1from1st day to7th day; the model group and sham operation group received daily abdominal cavity injection of the same dosage of saline from1st day to7th day.6rats in every group were randomly selected7th day after operation. Brain tissues were stained by triphenyl tetrazolium chloride (TTC) to count the percentage of infarct volume to the total volume of the cerebrum by image analysis.6rats in every group were randomly selected7th day after operation. Brain tissues were stained with hematoxylin and eosin (HE) to be observed pathological change and immuohistochemistry to detect CD34+cells. And then transmission electron microscope (TEM) was used to observe the ultrastructure of infiltrating cells. All datas were demonstrated by x±s and were analyzed with One-way ANOVA and t test by SPSS11.5statistics software, P<0.05was regarded to have statistical significance.Results:1Neurological behavioral assessments of cerebral infarction in ratsAfter operation, there were different performance in different group of rats. Rats in the sham operation group can not be seen abnormity. After the right middle cerebral artery occlusion (MCAO) model were established, the neurological syndromes were showed, the animals of the experiment group and the model group displayed paralysis in the left limbs,especially left forelimb.When lifted by the tail, unable to fully stretch out. Body fell towards the left side when moved freely and circled towards left side using left rear limb as the center. Before abdominal cavity injection, there was no statistical significance between the experiment group and the model group (P>0.05). The neurological deficit scores were as follow:sham operation group0±0, model group1.67±0.81, experiment group1.61±0.61. After abdominal cavity injection, the neurological deficit scores were no statistical significance between the experiment group and the model group (P>0.05), the neurological deficit scores were as follow:sham operation group0±0, model group1.56±0.62, experiment group1.50±0.50. There was no statistical significance between before and after abdominal cavity injection in the model group (P>0.05), and It was no statistical significance between before and after abdominal cavity injection in the experiment group (P>0.05).2The rate of body weight lossAfter establishing the model of rat cerebral infarction, the activity of rats decreased obviously, moreover motor disorder and weight loss could be observed to some degree, but the weight of sham operation group was heavier than before. The rate of weight loss in the model group after operation was (13.11±2.40)%, and that of the experiment group was (11.58±1.37)%, there was no significant difference between them (P>0.05).3Percent of infarct volumeThe infarction size was measured by triphenytetrazolium chloride (TTC) staining technique. Infarction zone in expriment and model group located the supply zone of middle cerebral artery(MCA), including cerebral codex and basipodite.The cerebral slices of sham operation group were stained uniform red. There were partly TTC-staining zones in the area where blood was provided by MCA in experiment group, and the infarct volume was significantly smaller than that of model group. The result of image analysis show infarction volume in model group was (223.89±10.31)mm3, the percent of infarct volume was (16.98±1.27)%. The volume and percent was respectively (150.54±17.26)mm3and (11.42±2.19)%in experiment group. The difference was significant (P<0.01).4The change of patholoty in the area of ischemic cerebral infarctionOne week after operation, tissue in the infarct zone were liquescent with many lymphocytes and mono-nucleus cells infiltrating around them in model group. In experiment group, part of the infarct zone was plerosised through proliferation of newly born capillaries and nerve-like cells and there were not many phlogistic cells infiltration. There were no necrotic change in the cerebral tissues of the sham operation group.5Immunohistochemistry to detect CD34positive cellsThere were CD34positive mono-nucleus cells in infarct zone in experiment group,while there were no CD34positive mono-nucleus cells in the model group and sham operation group, and there were taper-shaped cells in infarct zone in experiment group while none in model group.6The change of ultrastructure in the area of ischemic cerebral infarctionUnder electron microscope, there was no normal tissue structure in the infarct zone of the model group, it were liquescent with many lymphocytes and mono-nucleus cells infiltrating around them, the nerve cells were degenerative and necrotic in the infarct zone, mitochondria,Golgi body and endoplasmic reticulum were dissolved partly and there were many vacuole. Except liquescent with a few lymphocytes and mono-nucleus cells infiltrating, there were newly born capillaries and long ecphyma nerve-like cells in experiment group. It was no necrotic change of patholoty in sham operation group, we saw many normal nerve cells and glia cells, in nerve cells, intact cell membrane, clear margin, centered nucleolar, limpid nucleole, chromatin distributed uniformly, major euchromatin, ditissimus rough endoplasmic reticulum and ribosome around the cellular, many mitochondria and Golgi body, in glia cells, major heterochromatin in the cellular, lesser endochylema and cell organ compared with nerve cell.Conclusion:1rhG-CSF can mobilize CD34positive mono-nucleus cells and the cells can infiltrate into infarction zone.2There are newly born capillaries and long ecphyma nerve-like cells in infarction zone which maybe have repair function. |
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