| Ischemic penumbra is a hot spot studied in ischemic cerebral vasocular diseases. In this area, the cellular electrical activity induced or self-produced disappeared, but was able to sustain the stability of membrane potentials and the equilibrium of ion environment. Although the tissues of this area lost their physiologic functions temporarily, the cellular integrity was not injured and the cells were still alive. Some of those cells showed the changes of biologic information such as the alterationes of surtain gene and protein expression in this area. AIF and Caspase-3 are important reactive proteins in DNA damage. It could be actived in cellular response to DNA damage and induce AIF and Caspase-3 expression, which can promotes chromatin condensation and DNA fragmentation. This research was designed to study the role of AIF and Caspase-3 in focal cerebral ischemia and their mechanisms including following aspects:Objective1. To investigate the time and space distribution laws of the apoptosis inducing factor (AIF) and the relationship between the variations of expression of AIF and the neuronal apoptosis in cerebral injured region after focal cerebral ischemia-reperfusion in rats.2. To investigate the effect of Piper kadsura extract on neuronal apoptosis after after focal cerebral ischemia-reperfusion in rats.Methods1. The rats of middle cerebral artery occlusion and reperfusion were used as the research model. Infarction zones were confirmed by 2,3,5triphenyltetrazoliumchloride (TTC) staining. 2. The space and time distribution laws of apoptosis were observed by using deoxynucleotidyl transferase-mediated dUTP nick end labeling (Tunel) techniques after focal cerebral ischemia -reperfusion in rats.3. Using immunohistochemistric technique, we observed the expression of AIF and Caspase-3 at protein level in different ischemia-reperfusion time points.4. Piper kadsura extract was made up. then we observed its influence on the AIF,Caspase-3 expression and the neuronal apoptosis .Result1. The brain tissue was swollen and there was definite infarction after ischemia reperfusion. Using TTC staining, we could observe that the normal brain tissue was red ,while the infarction was grey.2. The TUNEL positive cellular nucleus is hyacinthine, which mainly distributed in perifocal area. At 3h after reperfusion they were present ,the number increased at 6h and 24h after reperfusion, then they decreased 72h after reperfusion later.3. AIF positive cells appeared in perifocal area at different time point after ischemia-reperfusion, and the regularity of time and space distribution were the same as those of TUNEL cells.4. The number of AIF positive cells, Caspase-3 positive cells and the neuronal apoptosis in perifocal area was lowered significantly at different time points After Piper kadsura extract intervention.Conclusion1. AIF take a significant part in neuronal apoptosis during cerebral ischemia- reperfusion injury.2. Piper kadsura extract may play protective function for the ischemic cerebral tissues by reducing apoptosis.
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