Experimental Study Of Microthrombosis In Brain Tissue Of Rats With Moderate-Severe Brain Trauma

ObjectiveTo evaluate the development value of microthrombosis and determine its possible relationship with microvessel density or Blood coagulation state after fluid-percussion moderate-severe injury in rats brain tissue.Methods(1) Use Lateral fluid-percussion brain injury model to produce experimental traumatic brain injury. (2) Sixty male SD rats (about 290-310g weight ) were randomly divided into eight groups: control group (six), artificial surgery group (six), three hours after surgery group (eight), six hours after surgery group (eight), twelve hours after surgery group (eight), twenty-four hours after surgery group (eight), forty-eight hours after surgery group (eight) and Nimotop intervene group. (3) Anaesthetise animals according expected time after injury and take out venous blood.(4) Take brain tissue after perfusion. Evaluate microvessel density and microthrombosis values by HE and Factor â…§ immunohistochemical staining after samples fixation and slice up. (5) Measure D-dimer (DD) content for blood samples to analysis the animals coagulation state when arrived the final timepoint. (6) Explore their regulation with time and relativity by statistical analysis. Try to clarify the effect of blood vessel expending medicines administration in the early brain trauma stage on the pathology and the coagulation state of the moderate-severe brain injury animals.ResultsThe fluid-percussion brain injury model was successful. The animals after injury showed coma, stopping breath, paralysis of the contra body, body twitch and epileptic symptoms. The general changes of brain tissue were evident. There were extradural and subdtlral hematoma forming by eyes and some animals had hemorrhage in skull base.Microthrombosis could be detected around the contuse areas after moderate-severe brain injury. The immunohistochemical staining was toevaluate microthrombosis density. Results showed that three hours, six hours, twelve hours, twenty-four hours, forty-eight hours groups were all higher than control and artificial surgery groups (p<0.01) and was up-regulated. There was no statistical difference between control and artificial surgery groups. Nimotop intervene group was lower remarkable than twenty-four group (p<0. 01).The microvessel density of three hours to forty-eight hours groups after injury were all decreased compared to control and artificial surgery groups (p<0. 01). The microvessel density droped down markedly before 6h point, and then rised gradually. There was no difference between control and artificial groups. Nimotop intervene group was much higher than twenty-four hours group (p<0. 01).The blood DD concentration of three hours to forty-eight hours groups after injury were all higher than control and artificial surgery groups (p<0.01) and was up-regulated. Compared with control group, the DD concentration of the artificial groups was higher(P<0.01). Nimotop intervene group was lower than twenty-fore group(P<0. 01)Statistical relativity analyze showed that there was relativity between DD concentration and microthrombosis density of all groups (r=0. 713, p<0. 01).Cone I us i on(D The fluid-percussion moderate-severe brain injury model was easily operation and high efficiency. The injury position and force degree were stable and could got relative consistent brain injury model. ? Microvessel density was reduced around contuse areas after moderate-severe brain injury and existed acute decrease stage and catabatic stage. (3) The rats blood was highly stagnated after moderate-severe brain injury. (D Microthrombosis could be detected in the microvessels after mid- and intensive brain injury, and it was well related with microvessels reduction. (5) Administering blood vessel expanding medicines properly in the early stage could lighten the spasm of microvessels after brain trauma and mitigate the formation of microthrombosis in the microvessels.