Influence Of Ulinastatin On Glutamate&GLT-1of Hippocampus In Rats At The Early Stage After Cardiopulmonary Resuscitation

Object:To investigate the effects of Ulinastatin(UTI) on histopathological,glutamate(Glu),adenosine triphosphate(ATP),glial glutamate transpor-1(GLT-1) changes of hippocampusin rats after cardiopulmonary resuscitation(CPR).Methods:Two hundred and ten male adult SD rats were randomly divided into3groups:sham-operation group (S group),normal saline resuscitation group (NS group) and ulinastatinresuscitation group (UTI group).Each group was divided into7subgroups by various intervals at0.5h,1h,1.5h,2h,2.5h,4h,6h after endovascular puncture in S group or after restoration ofspontaneous circulation(ROSC)in NS group and UTI group.Asphyxiation cardiac arrest andCPR model was used in NS group and UTI group.UTI was separately injected at105U/kg viafemoral vein within2min and1.5h after ROSC in UTI group,while only saline was treated in NSgroup.Anaesthesia,tracheotomy and vascular centesis were performed in rats without asphyxiationin S group.The pathological changes of hippocampus were observed under light microscope andelectric microscope;The concentrations of glutamic acid were measured with high performanceliquid chromatography(HPLC);The HPLC was used to measure ATP;The expression of GLT-1examined immunohistochemistry and Western blot;The changes of GLT-1mRNA were measuredby real-time PCR(RT-PCR).Results:(1)The hippocampal pathological changes of rats after cardiopulmonary resuscitationsuch as cellular degeneration,necrosis were remarkable in rats of NS group and UTI group,but forthe same time interval,there were miIder pathological changes in UTI group than those in NSgroup.(2)The ATP contents in hippocampus of rats in NS group were reduced in all seven groupsafter ROSC.The differences of ATP contents in rats between NS group and S group are significant(P<0.05,P<0.01);Compared with S groups,after0.5h,1h,1.5h,2h,2.5h,the ATP contents in UTIgroup became lower(P<0.05,P<0.01);Compared with NS group,the ATP contents in UTI groupincreased significantly at0.5h,4h,6h after ROSC(P<0.01).(3)The hippocampal Glu contents in ratsof NS group increased at all seven time points after ROSC,there were statistically significantdifferences between NS group and S group(P<0.01);Compared with S groups,at1h,1.5h,2h,2.5h,the Glu contents in UTI group were elevatory(P<0.05,P<0.01);Compared with NSgroup,the Glu contents in UTI group were lower significantly at0.5h,2h,2.5h,4h,6h afterROSC(P<0.05,P<0.01).(4)The GLT-1was located in glial cell membrane usingImmunohistochemical method.(5)The expression of GLT-1protein in NS group decreased at4h,6hafter ROSC,there was statistically significant difference between NS group and Sgroup(P<0.01);Compared with S groups,at2.5h,4h,6h, expression of GLT-1protein in UTI groupwas stronger(P<0.05,P<0.01),and that,they were higher significantly at2h,2.5h,4h,6h after ROSCin UTI group compared with NS group(P<0.05,P<0.01).(6)Compared with S group,at4h,6h,theexpression of GLT-1mRNA in UTI group was stronger(P<0.05),furthermore,the expression of GLT-1mRNA significantly increased at2h,2.5h,4h,6h after ROSC in UTI group compared withNS group(P<0.05).Conclusion:Therapeutic effects of Ulinastatin on brain injury of rat after CPR may by alleviatingenergy metabolic disturbance,regulating expression of GLT-1and decreasing Glutamic acidcontents.