Study On The Changes Of Mesenteric Microcirculation After Acute Internal Capsule Hemorrhage In Rats

Objective:1 To observe neuroethological changes and secondary injury around cephalophyma after acute internal capsule hemorrhage(ICH) in rats.2 To observe changes of jejunal mesenteric microcirculation hemodynamics and vascular cell adhesion molecule-1(VCAM-1) and intercellular adhesion molecule-1(ICAM-1) expression after ICH in rats.And investigate the pathogenesis of complication after acute ICH.Methods:1 Grouping animals:48 male Wistar rats were randomly divided into 2 groups: sham operated group and ICH group.The sham operated group had 16 rats and ICH group had 32 rats.Each group was allocated into 4 subgroups which were 3, 6,12,24h.2 Preparation of ICH model:According to the rats brain stereotaxic atlas,use the rats stereotaxis instrument,locat the hind limb of internal capsule.Open the skull with den auger,draw 100μl autologous blood from it's tail,inject the blood into the hind limb of right internal capsule.The same operation was performed on the sham operated group,but injected into commensurate Sodium Chloride.3 Neuroethological evaluation:Bederson's scoring criteria was used.Rats were held by the tail.Rats extended both forelimbs toward the floor were graded 0.Rats flexed the opposite side forelimb of the ICH were graded 1.Rats with 1 score sign had reduced resistance to lateral push toward the paretic side,were graded 2.Rats allowed to move freely were graded 3 if they circled toward the paretic side.4 Measurement of microcirculation hemodynamics:A microcirculatory microscope image analysis system was used to observe the jejunal mesentery microcirculation. Blood flow,shear rate,microthrombus of venules,width of marginal flow and axial flow in the arterioles were measured.Immunohistochemical technique was used to evaluate VCAM-1 and ICAM-1 expression.5 Preparation of brain pathological specimen:After observing mesenteric microcirculation,take the brain,make pathological sections around the area of ICH. Observe the brain's pathomorphology throung HE staining.6 Statistical analysis:Statistical software SPSS 11.5 was used.The differences of the sham operated group and ICH group were analysed with t-test.The comparison of interclass ICH groups were analysed by one-factor analysis of variance.Results:1 Neuroethological evaluation:Rats in the sham operated group hadnot evident neurologic impairment(P>0.05).All rats in ICH groug appearanced different extent neurologic impairment(P<0.05).2 Pathomorphology of the brain:Rats in the sham operated group hadnot evident pathomorphological changes.In ICH group,the position of hematoma was full of red blood cells,and inflammatory cells infiltration around it.There were cell spaces distention and cellular swelling in the perienchyma of the hematoma, which suggested the happening of cerebral edema.3 Mesenteric microcirculation hemodynamics:Blood flow of venules in all ICH groups decreased significantly(P<0.05).In 6,12and 24 h group,shear rate of veinules decreased markedly(P<0.05),while microthrombus increased(P<0.05). Shear rate was inversely correlated to microthrombus(r=-0.917,P<0.05).The width of marginal flow in ICH rats decreased,the ratio of width of marginal flow to width of arteriole reduced significantly(P<0.05).4 Expression of cell adhesion molecule:Mesenteric micrangium endothelial cell hadnot significant VCAM-land ICAM-1 expression(P>0.05).In ICH group, micrangium endothelial cells emerged VCAM-land ICAM-1 expression in the 6h subgroup rats(P<0.05).In the 12,24 h subgroup,VCAM-land ICAM-1 expression were increasing piecemeally.Conclusion:1 Using the brain stereotactic technique and injecting autologous venous blood from tail,we can duplicate the ICH rats mode successfully.2 The compression of hematoma to its perienchyma,cerebral edema,inflammatory infiltration,neuron necrosis,glial hyperplasia induced insecondary brain injured and neurobehavioral changes.3 The significant microvascular abnormality and blood-flow dysfunction is shown in mesenteric microcirculation of acute ICH rats,which can damage the target organs.Increasing VCAM-land ICAM-1 expression can mediated adherency and aggregation of leucocytes and vascular endothelial cells,which can aggratate the microcirculation disturbance.