| Backgroud and purpuse: The physiopathological process of intracerebral hemorrhage(ICH) is very complicated and we still know little about it so that the therapeutic means for ICH neuronal injury is inadequate even though there are treatments against intracranial hypertension and ICH complication. There has been some studies indicated that brain edema was assicated with cerebral ischemia around hematoma and the past researches demonstrated that ischemia/reperfusion injury can activate abnormal cellular signal transduction which finally leads to neuronal apoptosis or cell death and protein kinese C family members play a key role in this process. So in this study we try to find out whether there exists activation of pathological PKC signal transduction and intracellular calcium overload and the relationship between the former two aspects and neuronal injury. Further more, in PKC 13 isoenzymes ,nPKCδand cPKCγ are abundant in brain issues. So in our research we pay more attention to them.Although reports show that around the hematoma , increase of thrombogen activity, release of erythrocyte metabolite, decrease of brain blood flow and mechanical pressure of hematoma etc may take part in the pathological process of ICH but there is no reports about what we will try to study. Besides, a lot of observations demonstrated that as a blocker of calcium overload , Sibelium could protect neuron from cerebral ischemic injury. So we choose Sibelium as a therapeutic measurement to interfere in ICH injury and observe intracellular calcium concentration, PKC isoenzymes' expression and neuronal apoptosis in the area around hematoma.Method: ①The cerebral hematoma was made by intracranial injection of ivcollagensae into right lenticular nucleus and thus formed the rat model of ICH. ② We use immunohistochemical method to detect the expression of nPKCδand cPKCγand neuronal apoptosis at 0.5, 6, 24, 72, 120 hours after ICH. ③ Cellular caicium concentration was detected with fluorescent indictor Fura-2. ④ Neurological impairment was evaluated by somatosensory evoked potential (SEP). In addition, we investigated the changes of these results before and after Sibelium intervention.Results:1. The expression of PKC isoenzymes, nPKCδand cPKCγ, are markedly increased after ICH. The most significant changes lies in area around hematoma (P<0.01). And also apparente changes appears in hippocampus and cerebral cortex after ICH.2. The intracellular calcium concentration of brain tissue around hematoma increased markedly after ICH and got its peak at 24 hour-posthemorrhage. From 72 hour- posthemorrhage it began to descent and almost reach to its normal range at 120 hour-posthemorrhage.3. The immunohistochemical staining shows that after ICH cerebral neuronal apoptosis increased noticeably and got its peak at 72 hour-posthemorrhage. From 72 hour- posthemorrhage it began to descent and almost reach to its normal range at 120 hour-posthemorrhage.4. After Sibelium intervention, the expression of nPKCδ/cPKCγ were significantly inhibited along with the decrease of the number of apoptotic cell injury and the intracellular calcium concentration. And SEP results also indicated the improvement of neurological impairment: the peak of P1-N1 wave amplitude was increased after Sibelium intervention and the latent period of P1 and N1 were shortened (p<0.01) at the same time.Conclusion:1. Our research indicated that ICH could lead to up-regulation of expression of PKC isoenzyme, nPKCδ/cPKCγ. We still know little about the signal transduction pathway which is related to ischemic injury around the hematoma.2. In our research, the expression of PKC isoenzyme were related to cellular apoptosis and intracellular free calcium overload around the hematoma and this indicted that PKC signal transduction pathway participated in physiopathological process of neuronal injury after ICH. 3. Sibelium has an obviously protective effect on neuronal injury after ICH and manifested... |
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