| Ischemic cerebro vascular disease(ICVD) means that the intracranialarteries supplying the brain occur pipe wall pathological changes, leading tovascular stenosis, occlusion, blood stagnation, causing corresponding braintissue to the occurrence of ischemic necrosis and thus a correspondingneurological dysfunction. ICVD is characterized by high incidence, mortalityand recurrence rate. With the improvement of medical level, despite a gradualincrease in the survival rate after active treatment, but50%to70%ofsurvivors left by different degrees of learning and memory disorders andmovement disorders, seriously affecting the quality of life of patients. It hasbecome a main threat to human health. The brain will produce a serious ofpathological changes during the ischemia and hypoxia. In recent years, theresearch of mechanism of ICVD has become more and more abundant.However, whether cerebral ischemia will lead to the spinal cord injury(SCI) israrely reported at home and abroad, so further explore the pathogenesis hasvery important significance for clinical prevention and treatment on it.In recent years, using Traditional Chinese Medicine to treat diseases inmultitarget points attracts more and more attention. It is considered thatPolygala has protective effects on central nervous system (CNS) of animalmodels such as dementia and diabetes mellitus (DM),but there are seldomreports about effects of Polygala on SCI induced by cerebral ischemia.In this study, we established the model of one side cerebral ischemia bymiddle cerebral artery occlusion(MCAO) to explore the influence of focalcerebral ischemia on the anterior horn motor neurons of spinal cord and theprotective effects of Polygala on it, and to provide theoretical andexperimental bases for preventing and treating SCI induced by cerebral ischemia.Part ⅠEstablishment of model of anterior horn motor neurons of spinalcord injury induced by Focal Cerebral Ischemia in ratsObjective:In this study, the cerebral ischemia on one side was established byMCAO rat model. Changes of morphology and acetylcholinesterase(AChE)inthe motor neurons of spinal cord anterior horn lateral nucleus at different timepoints in MCAO in rats were observed to gradually establish the model ofanterior horn motor neurons of spinal cord injury induced by focal cerebralischemia in rats.Methods:20male SD rats were randomly divided into4groups (n=5), the cerebralischemia on one side was established by MCAO rat model, and the rats wereallowed to survive for1w,2w,4w and8w after operation. The cervicalenlargement was taken.Nissl’s staining was used to observe the morphology of the motorneurons of spinal cord anterior horn lateral nucleus. Karnovsky-Roots wasused to display the AChE of the motor neurons of spinal cord anterior hornlateral nucleus.Results:1The morphology of the motor neurons of spinal cord anterior hornlateral nucleusLight microscope: The control side in each group: Neuronal soma wasintact, apophysis was clear, nuclei rounded and situated in the middle of soma,Nissl body in small plaque shape. The motor neurons of spinal cord anteriorhorn lateral nucleus in the experimental side in1W group was close to thecontrol side in each group. The experimental side in2W group: Somas swellen,nuclei displaced. The experimental side in4W group: Neuronal somas werecoloured with different depth, somas swellen, nuclei displaced, part of thenissl body dissolved. The motor neurons of spinal cord anterior horn lateral nucleus in the experimental side in8W group was close to the4W group, andpart of the nuclei dissolved and cell depigmentated, the number of neuronreduced.2The AChE of the motor neurons of spinal cord anterior horn lateralnucleusThe control side in each group: the red-brown particles(positive AchEactivity) was clear, the outline of neuronal cell body was clear, the nuclei wasnot stained. The AChE of the motor neurons of spinal cord anterior hornlateral nucleus in the1w group in the experimental side was higher than thatin the control side (P<0.01). The AChE in2w group in the experimental sidewas lower than that in the control side (P<0.01). The changes were moreobvious with the extension of the course of disease (P<0.01).Conclusions:1Focal cerebral ischemia in rats can induce the pathological changes ofmorphology of the motor neurons of spinal cord anterior horn lateral nucleus.2Focal cerebral ischemia in rats can induce the changes of AChE in themotor neurons of spinal cord anterior horn lateral nucleus.3The model of anterior horn motor neurons of spinal cord injury inducedby focal cerebral ischemia in rats has been successfully established and thetime of cerebral ischemia is at least eight weeks.Part Ⅱ Protective effects of Polygala on the anterior horn motorneurons of spinal cord injury induced by the Focal Cerebral Ischemia inratsObjective:In this study, the model of the anterior horn motor neurons of spinal cordinjury induced by the focal cerebral ischemia in rats was established byMCAO. the changes of morphology and AChE and the ultrastructures ofsynapse in the motor neurons of spinal cord anterior horn lateral nucleus wereinvestigated to explore the protective effects of Polygala on the anterior hornmotor neurons of spinal cord in the focal cerebral ischemia in rats. Methods:15male SD rats were randomly divided into3groups (n=5): shamoperation group, model group and Polygala prevention group. The cerebralischemia on one side was established by MCAO rat model in model group andPolygala prevention group. The sham operation group only freed and ligatedexternal carotid artery (ECA),but not inserted fishing line from ECA into theinternal carotid artery(ICA), and the rest operation was same with the modelgroup and Polygala prevention group. The rats in Polygala prevention groupwere lavaged with Polygala (1.2g/kg/d) for8weeks after the operation. Therats in sham operation group and model group were lavaged with normalsaline (NS)(1.2g/kg/d) for8weeks after the operation.Nissl’s staining was used to observe the morphology of motor neurons ofspinal cord anterior horn lateral nucleus. Electron microscope was used toinvestigate the ultrastructure of synapse and motor neurons of spinal cordanterior horn lateral nucleus. Karnovsky-Roots was used to display the AChEof the motor neurons of spinal cord anterior horn lateral nucleus.Results:1The morphology of the motor neurons of spinal cord anterior hornlateral nucleusLight microscope: The control side in each group and the experimentalside in sham operation group: Neuronal soma was intact, apophysis was clear,nuclei rounded and situated in the middle of soma, Nissl body in small plaqueshape. The experimental side in the model group: Neuronal somas werecoloured with different depth, somas swellen, part of the nissl body dissolved,part of the nuclei dissolved or disappeared, the number of neuron reduced(P<0.01). The experimental side in Polygala prevention group: The numberand morphology of the motor neurons of spinal cord anterior horn lateralnucleus were better than that of the model group (P<0.01).2The ultrastructure of synapse and motor neurons of spinal cord anteriorhorn lateral nucleusLight electron microscope: The control side in each group and the experimental side in sham operation group: The ultrastructure of synapse andmotor neurons of spinal cord anterior horn lateral nucleus was normal. Theexperimental side in the model group: Chromatin marginated, nuclearmembrane blurred and dissolved, mitochondria swellen and denaturated, crestfractured, rough endoplasmic reticulum expanded and ruptured, ribosomemobilized in endochylema, lysosome increased. Synapse degeneration hadelectron-dense and electron-lucent changes. The experimental side in Polygalaprevention group: The ultrastructure of the synapse and motor neurons ofspinal cord anterior horn lateral nucleus were better than that of the modelgroup.3The AChE of the motor neurons of spinal cord anterior horn lateralnucleusThe control side in each group and the experimental side in shamoperation group: the red-brown particles(positive AchE activity) was clear, theoutline of neuronal cell body was clear, nuclei was not stained. Theexperimental side in the model group: The AChE in the experimental side waslower than that in the control side (P<0.01). The experimental side in Polygalaprevention group: The AChE in the experimental side was lower than that inthe control side, but it was higher than that in the experimental side of modelgroup (P<0.01).Conclusions:1Polygala can improve the pathological changes of morphology andultrastructure of the motor neurons of spinal cord anterior horn lateral nucleusand ultrastructure of the synapse induced by focal cerebral ischemia.2Polygala can upregulate the expression of AChE in the motor neuronsof spinal cord anterior horn lateral nucleus induced by focal cerebral ischemia.3Polygala has a good protection on the anterior horn motor neurons ofspinal cord injury induced by focal cerebral ischemia in rats... |
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