The Experimental Reaserch About The Protection Of Deferoxamine In Secondary Brain Injury After Cerebral Hemorrhage

Objective: Cerebral hemorrhage(intracerebral hemorrhage,ICH)is a highly threaten disease to human’s health.It is the common disease of the nervous system.The rate of disability and fatality caused by the disease is very high.Most survivors remain different kinds of nervous function defect.But the treatment of cerebral hemorrhage have no significant progress ever since.It has been found that the iron is usually severely overload in cerebral hemorrhage in some studies.The excessive iron is mainly from the broken red blood cells produced by cerebral hemorrhage hematoma.The iron around the hematoma can activate the oxygen free radicals which can subsequently cause brain injury.It can also induce inflammation,which plays an important role in brain injury after intracerebral hemorrhage.There is inflammation in the area of hematoma and surrounding areas,releasing the toxic contents of plasma protein and red blood cells,neutrophils and macrophages.Therefore,the clearance of the iron in the hemorrhage area can inhabit the inflammation,then reducing the subsequent neurologic impairment.Deferoxamine is a kind of metal complex of iron ion which have a high affinity to iron.It can quickly and effectively combine with iron ion,then take it out of the body.The content of iron ions can reduce hematoma,thereby reducing secondary neural injury after cerebral hemorrhage.Glial fibre acidic protein(GFAP)is a kind of intermediate filament protein,which mainly exist in astrocytes and have specific expression in it.It has been proved that the central nervous system damage can cause GFAP level increased significantly.This showed that the specificity in the ntermediate filament protein plays an important role in the central nervous system damage.GFAP,therefore,can be used as the central nervous system damage and the prognosis of a tumor-specific markers.Growth associated protein-43(GAP43)is a highly hydrophilic protein.It has a specific and unique expression in neurons.There is significant change in the central nervous system damage,thus it can be used as a prognosis of one of the indicators in the central nervous system damage.In this research,we treat the ICH-induced rats with the deferoxamine(DFA)by intraperitoneal injection and then observe the change of the iron ion concentration in the hemorrhage area,the impact of GFAP and GAP-43 expression.Thus to provide certain theoretical basis for clinical treatment.Methods: 144 healthy male SD rats which weight are between 250 g and 300 g,are randomly divided into three groups: ICH model group,deferoxamine treatment group and sham group.Fixing the rats on the stereotactic instrument after the rat were anaesthetized.Injecting non-heparinized autologous arterial blood into the right caudate nucleus to make the rat model of intracerebral hemorrhage.Each group of rats are injected 60μl autologous arterial blood.Selecting qualified rats according to the Longa standard after 2 hours.The intracerebral hemorrhage model group and the sham group are not given drug treatment.The deferoxamine treatment group are injected deferoxamine according to l00mg/kg in the abdomen two hours after the surgery,one injection every twelve hours.The period of treatment is seven days.Take the neurological dysfunction score test 2 hours,6 hours,1 day,2 days,3 days,5 days,7 days after ICH.Choose six rats at 1 day,3 days,7 days and 14 days,cut off the head of the rats and get the brain at four time points,then measure wet weight and dry weight.Calculate the water content of the brain tissue by dry-wet method.Choose rats at 1 day,3 days,7 days and 14 days,cut off the head of the rats and get the brain to measure the iron ion content of the brian tissue surrounding the hematoma.Take hematoma surrounding brain tissue and then cut into 6 slices to observe GFAP and GAP-43 expression by immunohistochemical methods.Take five high-power field in each section and calculate the positive express.And then use SPSS 13.0 statistical data to observe the alteration of each indicator at different phase from the hematoma surrounding brain tissue.Result:1 The Changes of the Water Content of the Rat Brain TissueThe brain water content of the ICH model group,the DFA group increase at 1 day,reach the peak on the third day after ICH and decrease on the seventh day.The DFA group have no statistically significant differences at the 1 day and seventh day(P>0.05).The sham group have no statistically significant differences at each time piont(P>0.05).The brain water content of the three groups have no statistically significant differences at the fourteenth day(P>0.05).There are significant differences among the remaining groups at each time piont(P<0.05).2 The Neurologic deficits of the ratsThe neurological function score of the ICH model group significantly increase,reaching the peak at the first day,and declined slowly from the first day to the third day after the ICH injury.The DFA group is lower than the ICH model group from the second day.The sham group is lower than the the DFA group and the ICH model group at every time point.3 The Changes of the Iron Content of the Rat Brain TissueThe iron content of the DFA group and the ICH model group begin to increase at the first day,reaching the top at the seventh day.The iron content of the sham group remain at the physiological level.The DFA group begin to become lower than the ICH model group at the third day.The ICH model group have no statistically significant differences at the 1day and 14 day(P>0.05).The DFA group have no statistically significant differences at the 1day and 14 day(P>0.05).The ICH model group and the DFA group have no statistically significant differences at the 1day(P>0.05).There are significant differences among the remaining groups at each time piont(P<0.05)4 The Changes of the GFAP ExpressionThe GFAP expression of the sham group remain at the physiological level at each time point.The GFAP expression of the ICH model increased significantly at 3day after ICH,reaching the top at 7day and decreased at 14 day.The DFA group become lower than the ICH model group three days after treatment.The ICH model group have no statistically significant difference at 3day and 14day(P>0.05).The DFA group and the ICH model group have no statistically significant difference at 1day(P>0.05).There are significant differences among the remaining groups at each time piont(P<0.05).5 The Changes of the GAP-43 ExpressionThe GFAP expression of the sham group remain at the physiological level at each time point.The DFA group and the ICH model group begin to increase at 1day after ICH,reaching the top at 7 day,and decrease at 14 day.The DFA group and the ICH model group have no statistically significant difference at 1day(P>0.05).There are significant differences among the remaining groups at each time piont(P<0.05).Conclusion:1 The method of rat autologous arterial blood injection can produce intracerebral hemorrhage model successfully,and the yield ratio is higher than the other methods.2 The content of the iron and water content around the hematoma have no positive relationship.3 The expression of GFAP after ICH involve in brain tissue necrosis,and is positively related to the concentration of the iron.4 The expression of GAP-43 after ICH involve in the concentration of the iron around the hematoma,and is positively related to the concentration of the iron.5 NGF is injected into the hematoma cavity can effectively reduce the content of iron content,thus to reduce the expression of GFAP and GAP-43.It is proved that the DFA can effectively reduce the iron content of local brain tissue,further alliviate neurological damage after cerebral hemorrhage,regulate the expression of nerve protection factor.This research provide theoretical basis for the DFA treatment after ICH.