Study Of Erythrocytes' Effect On The Formation Of Brain Edema After Intracerebral Hemorrhage In Rats

ObjectiveNon-heparinized autohemic arterial blood of the rat was injected into its caudate nucleus to establish a model of intracerebral hemorrhage. The changes of edema in various regions of the brain were measured at different time after hemorrhage. Meanwhile, the effects of erythrocytes and thrombin on the formation of cerebral edema after cerebral hemorrhage were studied to explore the pathophysiological mechanism of cerebral edema and the roles of erythrocytes and thrombin in this process. MethodsNonheparinized autohemic blood of the rat was taken out from rat's femoral artery and injected into its caudate nucleus immediately to establish a model of intracerebral hemorrhage.The changes of edema in the ipsilateral bassal ganglia(A) , ipsilateral cortex(B), contralateral bassal ganglia(C) and contralateral cortex(D) were measured at 1,2,3,5 and 7 days respectively after intracerebral hemorrhage. The rat's packed red blood cells, lysed red blood cells and hemoglobins at different concentrations were injected respectively into the rat's caudate nucleus. The changes of edema in various regions of the brain at different time were measured as above. 5U thrombin was injected into the rat's caudate nucleus and the changes of edema in various regions of the brain at different time were measured as above. ResultsThe brain water contents in the ipsilateral basal ganglia and ipsilateral cortex were markedly increased within 24 hours after intracerebralhemorrhage, with their peak time at the third day. The brain edema did not disappear after one week. Meanwhile there were no significant changes of brain water contents in contralateral basal ganglia and in contralateral cortex. The main effect of erythrocytes on edema was in the third day after intracerebral hemorrhage.There was a positive correlation between the severity of edema and the concentration of hemoglobin. The effect of thrombin on edema was mainly within 24 to 48 hours and did not disappear one week after intracerebral hemorrhage. ConclusionsThe formation of cerebral edema in rats was within 24 hours, with its peak at the third day and did not disappear one week after intracerebral hemorrhage.The regions of edema were mainly located at ipsilateral basal ganglia and ipsilateral cortex. Meanwhile there were no significant changes in brain water contents in contralateral basal ganglia and in contralateral cortex. The effect of erythrocytes on edema was mainly at the third day after intracerebral hemorrhage, as was probably relevant to the hemoglobin released by the lysed red blood cells. It's effect on edema formation was later than that of thrombin. These results provide a theoretical basis for therapeutic intervention.