Dynamic Expression Of HIF-1α And COX-2Protein In Perihematoma After Intracerebral Hemorrhage In Rats

BackgroundCerebral hemorrhage is one of the common and frequently-occurring diseases, which covers20%-30%of full stroke patients. Also it has a higher disability rate in brain vascular disease. It will make a serious affect on the patient's life quality. So it is meaningful to study the mechanism of injury of perihematoma brain tissue after intracerebral hemorrhage and to look for new thinking of treatment. In the past, a couple of research has been done by many scholars about the mechanism of the damage in brain tissue after intracerebral hemorrhage. Besides direct damage caused by the placeholder, there are some other factors, which caused secondary damages of the brain tissue, for example, cerebral ischemia, inflammatory reaction, free radical, blood components and so on. But many of these details are not very clear. This study aims to further exploring the secondary injury mechanisms in brain tissue around the hematoma after intracerebral hemorrhage, by investigating the dynamic changes of HIF-la and COX-2protein in perihematoma after intracerebral hemorrhage in rats. Meanwhile, it can provide new theoretical basis and new treatment ideas for clinical treatment.ObjectiveTo investigate the dynamic changes of HIF-1α and COX-2protein in perihematoma after intracerebral hemorrhage in rats, to study the relationship with brain edema, and try to explore the function mechanism in the brain tissue injury of the expression of HIF-1α and COX-2protein.MethodsThirty five healthy SD rats were randomly divided into sham operation group (n=5) and ICH model groups (n=30). Rats were sacrificed at6h,1d,3d,7d,14d and21d after operation respectively. The expressions of HIF-1α and COX-2were tested by using immunohistochemistry technique. The water content of brain tissue was measured by the wet-dry weight method.Results1. Dynamic expression of HIF-1α In sham operation group, HIF-1α nearly didn't expression after operation6h. But in the ICH model group, the expression of HIF-1α protein was obviously increased at6h, the peak value appeared at7d, began to decline obviously at14d and it has high expression at21d. Compared with sham operation group, the HIF-1α protein expression in the ICH model group after building the model6h was increased obviously and the difference was statistically significant (P<0.05). The difference of the expression of HIF-1α protein among different time point groups after intracerebral hemorrhage also had statistics significance (P<0.05).2. Dynamic expression of COX-2In sham operation group, COX-2had a very small amount of expression after operation6h. But in the ICH model group, the expression of COX-2protein was obviously increased at6h, the peak value appeared at3d, and began to decline obviously at14d, and it recovered to normal level at21d. Compared with sham operation group, the COX-2protein expression in ICH model group after building the model6h was increased obviously and the difference was statistically significant (P<0.05).The difference of the expression of COX-2protein among different time point groups after intracerebral hemorrhage had statistics significance (P<0.05).3. Dynamic changes of water content in brain tissue In the ICH model group, water content in brain tissue was increased from6h, the peak value appeared at3d-7d. and began to decline obviously at14d, and it recovered to normal level at21d.. Compared with sham operation group after building the model6h, water content in brain tissue of ICH model group was increased obviously and the difference was statistically significant (P<0.05). The difference of water content in brain tissue among different time point group after intracerebral hemorrhage had statistics significance (P<0.05).4. Relationship of HIF-1α protein expression. COX-2protein expression and water content in brain tissue There was positive correlation between HIF-1α protein and water content in brain tissue by Pearson's coefficient correlation (r=0.636, P<0.01). There was positive correlation between COX-2protein and water content in brain tissue by Pearson's coefficient correlation (r=0.927, P<0.01).Conclusion1. HIF-la and COX-2protein have an obvious expression in perihematoma after intracerebral hemorrhage in rats, and there are certain laws in the changes of HIF-1α protein and COX-2protein expression.2. In ICH model groups, with the extension of intracerebral hemorrhage time, there is a positive correlation between the expression of HIF-1α protein and COX-2protein and water content in brain tissue.