| Background and ObjectivesStroke is one of the three fatal diseases, which has the "three high" characteristics of high incidence,high morbidity and high mortality.lt could seriously affect people’s quality of life and bring heavy burdens to their families and countries. Stroke is divided into ischemic stroke and hemorrhagic stroke, Ischemic stroke accounts for more than80%of stroke, effective therapies of ischemic stroke require recanalization of occluded cerebral blood vessels, reperfusion of ischemic brain tissue can cause complex process of reperfusion injury,which can accelerate cell death. Apoptosis is considered one of the important mechanismes of cerebral ischemia and reperfusion injury.Apoptosis is also called programmed cell death(PCD),there are three main apoptosis pathways:mitochondria mediated apoptosis pathway,death receptor mediated apoptosis pathway and the endoplasmic reticulum stress. Among of them the mitochondrial pathway plays an important role.The mitochondria-mediated apoptosis pathway includes caspase-dependent and caspase-independent.Lots of proteases are released from the mitochondria to promote apoptosis.Ulinastatin is a protease inhibitor, which can inhibit trypsin,plasmin and other enzymes, inhibit the release of lysosomal enzymes by stabilizing the lysosomal membrane, inhibite the produce of myocardial depression factor, and which also has the functions of scavenging oxygen free radicals and inhibiting the release of inflammatory mediators. Ulinastatin was used in the treatment of pancreatitis and lung diseases. In recent years, there were reports that Ulinastatin was be used in the treatment of cerebrovascular disease dependents on its antioxidant and anti-inflammatory mechanism. Ulinastatin is still unclear about its specific mechanism of apoptosis. The focal cerebral ischemia-reperfusion injury model of rats was established with middle cerebral artery occlusion by thread ligation. The treatment group received UTI by intraperitoneal injection. To investigate the effects of Ulinastatin on expression of cytochrome c, apoptosis inducing factor (AIF) and the number of apoptosis in brain tissue of rats with cerebral ischemia-reperfusion injury.Materials and methodsFifty-four healthy male SD rats which weighted250-300g were randomly divided into sham operation group, ischemia-reperfusion group (control group), cerebral ischemia-reperfusion and ulinastatin treatment group (treatment group). Every group has18rats. The focal cerebral ischemia-reperfusion injury model of rats was established with middle cerebral artery occlusion by thread ligation referenced from zea-Longa’s with improvement, except the shame group. The control group and the treated group were generated by occlusion of the left MCA for2h followed by24h of reperfusion, the treatment group received UTI20000IU/kg by intraperitoneal injection as soon as the reperfusion, the other two groups were given the same dose of saline. The expression of cyt c in brain tissue of rats was detected with immunohistology staining, the expression of AIF in brain tissue of rats was examined by RT-PCR,the number of apoptosis in brain tissue of rats was analyzed with Tunel technique. All the data were expressed as x±s, SPSS17.0software was used to analyse this datas. The single factor analysis of variance was used to carry out the inner group comparisons. The significant difference was judged by α=0.05.Results 1. Effects of Ulinastatin on expression of cytochrome C in brain tissue of rats with celebral ischemia-reperfusion injuryThe positive cell counts of cytochrome c in Sham group, control group and treatment group are3.20±0.75,98.40±7.28and74.80±3.37respectively.The expression of cyt c in brain tissue of rats in the control group and treatment group were significantly higher than which in the sham operation group(P<0.05).And the expression of cyt c in brain tissue of rats in the treatment group were significantly lower than which in the control group(P<0.05).2. Effects of Ulinastatin on expression of AIF in brain tissue of rats with celebral ischemia-reperfusion injuryThe relative expression levels (OD) of AIF in sham group, control group and treated group were0.126±0.023,0.433±0.075and0.186±0.0320respectively. The expression of AIF in brain tissue of rats in the control group and treatment group were significantly higher than which in the sham operation group (p<0.05). And the expression of AIF in brain tissue of rats in the treatment group were significantly lower than which in the control group(p<0.05).3. Effects of Ulinastatin on number of apoptosis in brain tissue of rats with celebral ischemia-reperfusion injuryThe number of apoptosis in sham group, control group and treated group were6.60±.02,48.60±4.32and28.40±3.32respectively. The number of apoptosis in brain tissue of rats in the control group and treatment group were significantly higher than which in the sham operation group(P<0.05). And the number of apoptosis in brain tissue of rats in the treatment group were significantly lower than which in the control group(p<0.05).Conclusions1. The number of apoptosis and the expressions of cyt c, AIF in brain tissue of rats are significantly increase in the cerebral ischemia-reperfusion groups.lt shows that cyt c,AIF and apoptosis involve in brain ischemia and reperfusion injury.2. Ulinastatin can reduce the number of apoptosis, and can down-regulate the expressions of cytochrome c and AIF in brain tissue of rats with the cerebral ischemia-reperfusion injury. The inhibition of Ulinastatin on apoptosis may be related to the reducing of mitochondria damage and the inhibition of apoptosis ways of mitochondrial pathway... |
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