| Objective: To observe the morphology change of microglia and neuron and expressing rule of bFGF in cerebral ischemia penumbra of Wistar rat brains in different period after permanent middle cerebral artery occlusion. To realize protection and plerosis of bFGF to brain. To provid experiment foundation to the convalescent therapy of cerebrovascular disease.Methods: Forty-eight male Wistar rats were divided into two groups randomly. Eight of them for fales operation group, forty of them for permanent focal cerebral ischemia group. The latter were divided into five subsections ( ischemia for 3days, 7days, 14days, 28days and 42days) according to ischemia time. In fales operation group, only exposure the middle cerebral artery but not block it, then get the brain after headbroken, while in permanent focal cerebral ischemia group , the animal model of middle cerebral artery occlusion were replicated, and the brain were obtained after ischemia for 3 days, 7 days, 14 days, 28 days and 42 days according to the selecting standard. HE staining and immunohistochemical staining were underwent respectively. The morphology change of microglia and neuron in ischemia penumbra and the expressing rule of bFGF in cortex and hippocampus were observed . Results'. The neuron and tissue structure had no significant change in fales operation group after HE staining. Neuron degeneration in infract region and a few microglia appearance in ischemia penumbra were observedafter ischemia for 3days. The number of neuron reduced, arrangement disorder and karyopyknosis , gitter cell formation in infract region and microglia increased and small vessels expanded in ischemia penumbra were observed after ischemia for 7days. Necrosis region having no expand and gitter cell increased in infract region, microglia increased and small vessels expanded significantly ischemia penumbra were observed after ischemia for 14days. Infract region stabilized and the number of microglia in ischemia penumbra decreased after ischemia for 28 days. The microglia in ischemia penumbra tend to stable .bFGF could be expressed in neuron and in neuroglial cell, specially in cell plasm and membran. The study indicated that bFGF expressed weakly in the rat brain of fales operation group, while in permanent focal cerebral ischemia group, the expression of bFGF in neuron and neuroglial cell in ischemia penumbra began after ischemia for 3 days, increased significantly after 7 days, reached peak after 14 days, descended after 28 days and still presented in some degree after 42 days. The same expressing rule could be observed in hippocampus.Conclusion : 1) Microglia began to emerge in focal cerebral ischemia penumbra after 3 days, the mumber of microglia increased after 7 days , increased significantly after 14 days, began to reduce after 28 days and tend to stableafter 42 days. The hyperplasia and hypertrophy of microglia occurred not only in the earlier period cerebral ischemia, but also in the later period . This indicated that the activity of microglia existed in the whole pathology procedure. Microglia could become phagocyte to clean dead neuron, and protect the living neuron in ischemia penumbra at the same time . That is to say that microglia can exert the action not only of cell killer, but also of neurotrophic factor to plerosis neuron .2) bFGF expressed weakly in normal brain. The expression of it in neuron and in neuroglial cell in ischemia penumbra began after ischemia for 3 days, increased significantly after 7 days, reached peak after 14 days, descended after 28 days and still presented in some degree afterfor 42 days. The same expressing rule could be observed in hippocampus. bFGF could prevent the degeneration of neuron, prolong its left and accelerate the growth of axis-cylinder, furthermore it was the pro-mitosis of glial cell and could accelerate the proliferation of neuroglial cell. This indicated that bFGF plays an important role in plerosis period of cerebral ischemia. To master the expressing rule of bFGF could develop a new pathway for treating cerebrovascular... |
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