| Cerebral infarction(CI) is the most common form of stroke, mortality and morbidity of which are very high, based on the primary prevention and secondary prevention,how to reduce mortality and morbidity have to be particularly important。Neuronal deathy forms contain necrosis and apoptosis in pathological mechanism of cerebral infarction, apoptosis is the main form in delayed neuronal death, which is mainly found in the ischemic penumbra。The number of apoptotic cells decide the size of the volume of final infarct。So inhibition of apoptosis and enhancing cell resistance to the ability of hypoxia to become effective means of clinical intervention with cerebral infarction。 HIF-1α and caspase-3are important factors of improving cell viability and apoptosis execution against hypoxia。Therefore analysis of relevance and monitoring dynamic variation of HIF-1α and caspase-3have practical significance。Objective:A suture for preparation of middle cerebral artery obstruction(MCAO) CI model in SD rats, detecting the expression of HIF-1α and caspase-3at special time points after acute cerebral infarction, exploring dynamic varying significance and correlation of both in SD rats with acute cerebral infarction, providing the experimental basis for effective clinical intervention on acute cerebral infarction。Methods:1、 Groups:36clean grade(SPF) young SD rats with250-320g were randomly divided into there groups—operation group(SS group,16rats), sham operation group(JSS group,16rats), control group。The first two groups are again divided into ABCD four groups, each one is responsible for collecting blood samples by cutting their tails at0.5h,2h;3h,6h;12h,24h;72h,168h。 Number of male and female rats occupy half respectively in each subgroup。2、 Modeling and screening methods:Reference to modified suture for preparation of MCAO model in SD rats。Rats have to have neurological deficit score after awake, the model rats be brought into test if score within1-3。3、Serum extraction and laboratory methods:Collecting blood1-2ml at each time point and lying in4℃refrigerator for one hour, then obtaining the upper serum through centrifugation, then eliminating hemolysis, at last serum samples are placed in-70℃refrigerator for cryopreservation。We measured OD value of the various serum samples of HIF-1α and caspase-3by ELISA and calculated the corresponding concentration by drawing the standard curve。At last we adopted one-way ANOVA and spearman rank correlation analysis to analyze the concentration change of HIF-1α and caspase-3at each time point。Results:1、SD rats neurological deficit score:the score of the operation group is1.63±0.55, which is obviously greater than the score of the rest of groups(P<0.05)。2、Expression of HIF-1α:The expression values of HIF-1α in the operation group were significantly higher than that in other groups, the difference was statistically significant(P<0.05)。The difference of HIF-1α expression was statistically significant at each time point in operation group(P <0.05)。The expression of HIF-1α began at0.5h of operation group, then increased gradually, reached apeak at12h, decreased gradually after12h, and the values compared with the other groups was no significant difference。3、 Expression of Caspase-3:?4、TTC staining:The brain tissue supplied by the right middle cerebral artery was stained into white, which was different from red—the color of normal brain tissue, suggesting that cerebral infarction is existent。Conclusion:1、Modified suture for preparation of MCAO model in SD rats is a ideal modeling method。2、Neurological deficit score among1-3was considered to be successful by us, it was confirmed by TTC staining, so neurological deficit score was recommended as the standard for selecting success or not of MCAO model.3、HIF-1α in rats with CI started expression at0.5h, and reached the peak at12h。The findings suggest that HIF-1α involve in the pathological process of ultra-early,early CI, stabilize the intracellular environment of surviving neurons in the infarct region, and play an important role in resistance to hypoxic state。4、Caspase-3in rats with CI started expression at0.5h, but reached the peak at12h。The findings suggest that the surviving neurons appear apoptosis in sustained serious hypoxic environment, the most serious degree of which appear at24h after CI。5、There weren’t significant correlation between the expression of HIF-1α and the expression of caspase-3。... |
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