Experimental Study Of Erythropoietin On The Prevention And Cure Of Cerebral Vasospasm(CVS) After Subarachnoid Hemorrhage(SAH)

Object: to observe the cerebrovascular morphological changes and the expression of nuclear-transcription factor-Kappa B(NF-κB) and endothelial nitric oxide synthase(e NOS) in the blood vessel wall of the subarachnoid hemorrhage model in SD rats, to explore erythropoietin effect on the prevention and treatment and mechanism of cerebral vasospasm after subarachnoid hemorrhage.Methods: 60 healthy adult SD rats were randomly divided into normal group(n = 6), sham group(n = 18), subarachnoid hemorrhage(SAH group, n = 18), SAH+ EPO group(treatment group, n = 18 rats). The normal group without any treatment in the seventh killed, and the rest was divided into three sub-groups after the second injection of blood 1d, 3d, 7d. Model use autologous arterial blood into the cisterna magna double injections of blood. Experimental animals were killed after the sham group and SAH group modeling success at the corresponding time points, the treatment group is killed at the corresponding time points after intraperitoneal injection of EPO(3000IU / kg) daily. The brain pontine basilar artery were removed at corresponding time points after the animal by modeling, to observe the basilar artery specimens using hematoxylin- eosin staining(HE staining) after slicing, to mesasure the expression of NF-κB and e NOS in vessel wall by immunohistochemical staining, and the results were statistically analyzed.Results: 1.Hematoxin Eosin(HE) results: 1) The basilar artery intima and adventitia smooth, endothelial cell structural integrity, internal elastic membrane no folds or broken, smooth muscle layer is thin, smooth muscle cells arranged in regular and no inflammatory cell infiltration in the normal control group and the sham group. 2) SAH groups: The first day: Endometrial showing wavy change and structural integrity; Smooth muscle cell proliferation, thickening of the smooth muscle layer, still neatly arranged; Epicardial no obvious inflammatory cell infiltration. The third day: Endometrial folds deepen, even broken and endothelial cell edema, degeneration; Smooth muscle cell further proliferation, smooth muscle layer is further thickened and irregular arrangement; The outer membrane of connective tissue proliferation, there are a small number of inflammatory cells. The seventh day: Endometrial folds further deepen, and even some appear broken, endothelial cell edema, degeneration or necrosis; Smooth muscle cell proliferation and further increased, some necrosis and smooth muscle layer is further thickened, irregular arrangement; The outer membrane of connective hyperplasia, inflammatory cell infiltration heavier than before. 3) Their pathological changes similar to the treatment group at all time points, but a lesser extent.2.The base artery wall thickness and diameter: 1) There were no significant difference changes with the inner diameter of basilar and artery wall thickness in the normal and the sham groups(P> 0.05); 2) The SAH group at each time point of vascular wall thickness, vessel diameter increased than the sham group vessel wall thickness(P <0.05), blood vessel diameter narrowing(P <0.05); 3) The treatment groups compare with SAH group at each time point, it was the larger the inner diameter of basilar artery and thin wall(P <0.05).3.Immunohistochemistry The expression of NF-κB: To detect NF-κB weak immunoreactivity in the normal group and the sham group; NF-κB immunoreactivity was seen in the SAH group and the treatment group at each time point, it could be observed in the intima and smooth muscle layer that were brown or tan, and it located in the cell cytoplasm and nucleus. Normal group and the sham group was no difference in NF-κB expression at each time point(P> 0.05); SAH group and the sham group comparison NF-κB expression increased at each time point(P <0.05); Treatment group NF-κB expression was decreased than the SAH group(P <0.05).The expression of e NOS: To detect NF-κB strong immunoreactivity in the normal group and the sham group; NF-κB immunoreactivity was seen in the SAH group and the treatment group at each time point, it could be observed in the intima and smooth muscle layer that were brown or tan, and it located in the cell cytoplasm. Normal group and the sham group was no difference in e NOS expression at each time point(P>0.05); SAH group and the sham group comparison e NOS expression decreased at each time point(P <0.05); Treatment group e NOS expression was increased than the SAH group(P <0.05).Conclusion:1. autologous arterial blood into the cisterna magna double injection method can be successfully established model of subarachnoid hemorrhage.2. The NF-κB expression increased after subarachnoid hemorrhage on the basilar artery, which increases the degree consistent with the morphological changes of basilar artery, indicating NF-κB may be involved in the mechanisms of delayed vasospasm.3. The e NOS expression weakened after subarachnoid hemorrhage on the basilar artery, which the degree of weakening contrary to the morphological changes of basilar artery, indicating e NOS may be involved in the mechanisms of delayed vasospasm.4.Erythropoietin possibly through inhibition of NF-κB activity and increased e NOS activity to relieve cerebral vasospasm after subarachnoid hemorrhage.