| Cerebral vasculars disease is one of three diseases that do harm to people's health. Among cerebral vasculars disease, ischemia cerebral vasculars disease is high incidence rate, high handicapping rate, high death rate and it endangers our health. Once the ischemia occuerred, it will lead to not only the hypoxia and metablic disturbance, but also the accumulation of the toxic metabolic products can cause the ischemic injuries and even the death of the neurons. Early reperfusion is important to the survival of the neurons, but the active oxygen produced by it will deteriorate the injury to the neurons. At the stage of cerebral ischemia/reperfusion, a series of sub-cellular and molecular pathologic changes had also taken place in cells of damaged regions, which could make membrane, cell organs and DNA damaged. The damages of DNA might be the result of many factors as well as be the reason of many new changes in cell. More and more studies have showed that apoptosis caused by DNA damage participated in the pathological course of the brain ischemia reperfusion injury and became one of the main causes of ischemia reperfusion injury. Apoptosis is an active, manipulative and normal phenomenon, which is regulated by a series of proteins. This research can provide good ideas to forbid apoptosis of neurons through knowing DNA damage at neurons of ischemia reperfusioninjury and proteins involving in apoptosis. Now among proteins involving in apoptosis, Bcl-2 proteins family is that we care most. Bax and Noxa of Bcl-2 proteins family are related to apoptosis caused by DNA damage, but at neurons we don't prove yet. The purpose of this study is to investigate the form of DNA damage at early stage of ischemia reperfusion injury and the relation between Bax and Noxa and apoptosis of neurons in order to understand the mechanism of ischemia reperfusion injury and to provide basis of treatment.In the experiment, we established neuron ischemic and ischemia-reperfusion model in vitro via neuron primary culture. Divide the identified mature neurons as normal group and ischemia-reperfusion group. At each time point, we observed morphological changes, in situ detected DNA breaks, and observed expression changes of Bax and Noxa. We observe transposition of Noxa initially. Results in the experiment were shown as following:(l)HE stain indicates: We can observe that the cytoplasm of neuron is pin and the nucleus is blue through optical microscope. The morphological of neuron without being treated is normal. The nucleus can be seen clearly. The morphological of the part of neurons is changed at 2 hour of reperfusion. The cell bodies are shrinkage or swelling. The cell body is changed to be small, cytoplasm is changed to be concentration, chromatin is changed to be coagulation and the enation is changed to be short following the increasing time of reperfusion.(2)Klenow method in situ detection indicates: The average gray of Klenow positive cells without be treated is 72.4+1.00. The average gray of Klenow positive cells is increased following the increasing time of reperfusion. The highest average gray is 135.5+ 1.31 at 2 hour of reperfusion. Then the average gray of Klenowpositive cells is decreased following the increasing time of reperfusion. Klenow positive Neurons decreased obviously at 12 hour after reperfusion.(3)TUNEL method detection indicates: The ratio of TUNEL positive neurons without be treated is (10.5+1.29)%,and the ratio is increased following the increasing time of reperfusion. The highest ratio is (86.5+4.72)% at 6 hour after reperfusion. Then the ratio is decreased following the increasing time of reperfusion. TUNEL positive neurons decreased obviously at 12 hour after reperfusion.(4)Bax flow cytometer indicates : The ratio of Bax positive neurons without be treated is(1.6+0.07)%,the ratio is increased following the increasing time of reperfusion. The peak of the expression of bax is at 2 hour after reperfusion and the ratio of bax is (10.1+0.20)% .The quantity of positive neurons decreased...
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