The Correlation Study About Protease-activated Receptor-1 And Angiogenesis After Cerebral Hemorrhage In Rats

Objective:Through the establishment of experimental intracerebral hemorrhage(ICH)model in rats,to observe the relationship between protease-activated receptor 1(PAR1)and brain angiogenesis in rats after ICH,in order to provide new ideas for the treatment and rehabilitation of cerebral hemorrhage.Methods:1.100SD rats were randomly divided into two groups:sham operation group(sham group)(n=25),cerebral hemorrhage group(ICH group)(n=25),ICH+PAR1 inhibitor group(PI Group)(n=50);PI group was randomly divided into two subgroups:ICH with high dose PAR1 inhibitor group[PI(H)group(n=25)],ICH with low dose PAR1 inhibitor group[PI(L)group(n=25)].Each group was randomly divided into 1d,3d,7d,14d,21d five time points,each time point of 5 rats.2.Cut off the tail of rats to get blood 50ul without anticoagulated,using rat brain stereotaxic apparatus,the anticoagulant autologous blood into the right basal ganglia of rat brain to establish the model of cerebral hemorrhage.The sham operation group rats were inserted pin without blood.3.Medication:PAR1 inhibitor SCH79797 was dissolved in 2ml saline for intraperitoneal injection[PI(H)250ug/kg,PI(L)25ug/kg]after 2h of the operation in PI groups,Sham group and ICH group injected 2ml saline in the same way.4.Measure the rats' neural function with modified neurological severity score scale(mNSS)at Id,3d,7d,14d,21d;The higher score represents the worse of dysneuria;After that the rats were sacrificed at the corresponding time points,measured the water content of brain tissue around the hematoma by dry wet weight method at 1d,3d,7d.Observed the microvascular in the brain tissue surrounding the hematoma by HE staining method;Immunohistochemistry was used to observe the number of vascular endothelial growth factor(VEGF)positive cells and the expression of von Willebrand factor(vWF)positive microvessel density(MVD).Results:1.mNSS:?Sham group rats did not appear nerve dysfunction.?ICH and PI group had different degrees of neurological deficits after cerebral hemorrhage,and the neurological function score was the highest in each group at 3d time point,the nerve function recovered gradually(P<0.05)?PI(H)group compared with ICH group,the neurological score at each time point increased significantly,the difference was statistically significant(P<0.05)·? PI(L)group compared with ICH group,the neurological score at each time point was significantly reduced,the difference was statistically significant(P<0.05).2.The water content of brain tissue:?The water content of the brain tissue around hematoma in ICH group and PI group was significantly higher than that in group Sham,and reached the peak at 3d.? PI(H)group brain tissue water content was significantly higher than that of ICH group at ld,3d,7d,the difference was statistically significant(P<0.05).? The brain water content of PI(L)group was significantly lower than that of ICH group at ld,3d,7d,the difference was statistically significant(P<0.05).3.HE staining observation of angiogenesis:?There could be seen the brain tissue around needle was uniform in Sham group at each time point;occasionally seen a small number of microvessels.? Compared with Sham group,ICH and PI group showed different degree of vascular endothelial cells,vascular structure and microvascular increase at each time points,the most obvious increase at 14d,angiogenesis in ICH and PI group were significantly increased compared with the same time point of Sham group.?Neovascularization in PI(H)group was lower than ICH group.?Neovascularization in PI(L)group was higher than ICH group.4.The number of VEGF positive cells:?VEGF expression of ICH and PI group was significantly higher than that in group Sham after cerebral hemorrhage at ld,3d,7d,14d,21d(P<0.05)??The expression of VEGF in group ICH and PI after intracerebral hemorrhage increased at 1d,and reached the peak at 14d.?PI(H)group compared with ICH group,the number of VEGF positive cells decreased at each time point,the differences were statistically significant(P<0.05).?PI(L)group compared with ICH group,the number of VEGF positive cells increased significantly at each time point,the difference was statistically significant(P<0.05).5,vWF positive MVD:? MVD in ICH and PI group were significantly higher than those in Sham group(P<0.05).? MVD in the PI and ICH group began to increase at 1d after intracerebral hemorrhage,and reached the peak at 14d.?)MVD in PI(H)group was reduced at each time point compared with the ICH group,the difference was statistically significant(P<0.05).? MVD in PI(L)group was increased at each time point compared with the ICH group,the difference was statistically significant(P<0.05).Conclusion:1.The physiological and pathological processes of using non anticoagulation autologous blood injection method to establish the model of cerebral hemorrhage in rats are similar with human,and it do not change the thrombin and so on in blood which were PAR1 activator activity,it is the ideal animal model to carry out this experiment.2.Properly inhibition of PAR1 can reduce the degree of brain edema in rats with experimental intracerebral hemorrhage.3.Properly inhibition of PAR1 may promote angiogenesis in experimental intracerebral hemorrhage rats by up regulating VEGF expression.4.Properly inhibition of PAR1 is beneficial to the recovery of neurological function in rats with experimental intracerebral hemorrhage.