The Experimental Research Of Thrombin’s Damage Effect On Cerebral Vessels Of Rat Model After SAH

Objectives:To study the damage effect on cerebral vessels after the thrombin(TM) was injected into the cisterna magna and the relationship between that and vasospasm of basilar arterial in vivo; To discuss whether there is a difference of the TM’s damage effect on cerebral vessels in cerebrospinal fluid(CSF) between subarachnoid hemorrhage(SAH) models and non-SAH models in rats.Methods:(1) Take the method of that TM was injected into the subarachnoid space via cisterna magna of rat to make the TM model, take the method of "double hemorrhage injection" to make the SAH model, the blood and TM model was made on the basis of SAH model, the TM was injected into the subarachnoid space after the first blood injection.(2) Experimental animal group:Divide the rats which were at the level of clean and health into3groups by random number table method, the A1(Control) group, the A2(Pure TM) group and the A3(Blood and TM) group.①In the A1(Control) group, rats were operated sham-operation, the injectant was corresponding dose of normal saline(NS);②In the A2(Pure TM) group, the TM(3U) was only injected into the animals’ subarachnoid space via cisterna magna;③In A3(Blood and TM) group, the animals were all SAH models, and the TM(3U) was injected into the subarachnoid space after the first blood injection.(3) Three days after operation, animals were perfused to death and then the basilar arteris of rats were carried out histopathologic examination. Using Image-Pro Plus(IPP)6.0to measure the rats’basilar artery lumen cross-sectional area of all groups, the specimen were drawed on four points as follows, the location of0.2mm under the superior cerebellar artery, the top and bottom of starting point of the anterior arterya, and the intersection of basilar artery and vertebral artery to; each specimen was to be detected the expressive level of Proteinase-activated Receptor-1(PAR-1) and Tumor necrosis factor-a(TNF-a) by immunohistochemistry, and then we took the mean optical density(MOD) value of PAR-1and TNF-a as the semiquantitative indicators to conduct statistical analysis.Results:①Compared with the control group(A1), the rats’basilar artery lumen cross-sectional area of group A2are smaller, there was a significant difference between them with P<0.05, and the MOD value of PAR-1and TNF-a of basilar artery were higher than group A1, there were significant differences between them with both P<0.05;②With equal dose of TM, the basilar artery lumen cross-sectional area of SAH model (group A3) are smaller than the non-SAH model(group A2)’s, there is a significant difference between them with P<0.05; meanwhile, the MOD value of TNF-a of group A3is lower than group A2, there is a significant difference between them with P<0.05; but there is no significant difference in MOD value between group A2and A3with P=0.42>0.05.Conclusions:①The basilar artery lumen cross-sectional area will become smaller, the expressive level of thrombin receptor PAR-1and inflammatory factor TNF-a will increase when TM is injected into the subaracnoid space of rat, which indicates that the TM in CSF will lead to cerebral vasopasm(CVS) and damage effcet on cerebral vessels;②Under the conditon of equal dose of TM in CSF, there is no significant difference between SAH model and non-SAH model on the basilar artery lumen cross-sectional area, the expressive level of PAR-1and TNF-a, which indicates that no matter whether there is SAH or not, the TM will lead to CVS. Objectives:To study the correlation between the time of TM in CSF of SAH model and its damage effect level on cerebral vessels in rat; to explore the dose-effect relationship between TM which is in CSF and CVS level in rat SAH models. Methods:(1) Take the method of double hemorrhage injection via Cisterna magna of rats to make the SAH models, and the blood and TM models were made by that the TM of different dose were injected into rats’subarachnoid space after the first hemorrhage injection.(2) Experimental animal group:the rats which meet the requirements were divided into2groups by random number table method, the group B1(3day) and the group B2(7day). All animals were SAH models, in group B1and B2, four groups were set up respectively:①Whole blood group,②Whole blood+TM(1U) group,③Whole blood+TM(3U) group,④Whole blood+TM(5U) group.(3) After operation and based on the design, the rats were perfused to death on the third or seventh day, then the basilar arteris of rats were carried out histopathologic examination. Using Image-Pro Plus(IPP)6.0to measure the rats’basilar artery lumen cross-sectional area of all groups, each specimen was to be detected the expressive level of PAR-1and TNF-a by immunohistochemistry, and then we took the MOD value of PAR-1and TNF-a as the semiquantitative indicators to conduct statistical analysis.Results:(1) Compared with group B1.③, the basilar artery lumen cross-sectional area of group B2.③are smaller, the difference between them is statistical significance with P=0.003<0.05, the MOD value of PAR-1and TNF-a are higher, the differences are statistical significance with P=0.043<0.05and P=0.004<0.05;(2) In group B1, with the TM concentration increased, the basilar artery lumen cross-sectional area became smaller, and the MOD value of PAR-1and TNF-a of basilar artery gradually increased, the overall difference is statistical significance with P<0.05, furthermore, in the pairwise comparison, the differences of the3variables are all statistical significance between each other with P<0.05;(3) In group B2, as similarly as group B1, the overall difference and pairwise comparison of the3variables in the four groups are all statistical significance with P<0.05.Conclusions:①In rat SAH model, with the time of TM in subarachnoid space extend, the basilar artery manifests aggravating CVS;②In SAH model, the more dose of TM in the CSF, the more serious CVS of the basilar artery, there is a positive correlation.