The Effect Of NR1/TFR Chimeric Epitope Vaccine On Cerebral Ischemia And Reperfusion Injury In Rats Model

Objective: After cerebral ischemia and reperfusion, the ascensus andactivation of NMDAR in brain is possibly an important element.NR1/TfR recombinant vaccine that had been made by our groups in early,could produce the anti-NR1which trans-through blood-brain barrier. Toevaluate the effect of this vaccine in cerebral ischemia and Reperfusioninjury, We established the animal model of cerebral ischemia andreperfusion by obstructing two blood vessels combination hypotension inrats, and analysed the neurological behavior score, the neuronal densities,the diversity of glutamic acid in cerebrospinal fluid after reperfusion.Methods:(1) We defrost and recover the NR1/TfR recombinant vaccinewhich we make early days and via the gene sequencing. The bacteriawhich contain the correct genes is made of the oral vaccine (containing1X109cfu/ml) would be prepared by plate culture counting method;(2)Seventy-two male SD rats were randomly divided into three group: shamgroup(take saline2ml orally), saline group(take saline2ml orally),vaccine(take vaccine2ml orally). The saline and vaccine were fed bygavage in four times within two weeks; we begin to established the modelafter four days of the last feed. Sham group just separate bilateralcommon carotid artery and femoral artery, and monitor mean arterial blood pressure (MAP). The model of cerebral ischemia and reperfusion insaline and vaccines group is obstructing two blood vessels+hypotension.The rats in all groups are observed the neurological behavior score at1,24hours after reperfusion. The all rats are drew the cerebrospinal fluidoff and executed for cerebral tissues at24,48,72h after reperfusion. Theparaffin sections were used for HE staining to calculate the neuronaldensities. The glutamic acid in cerebrospinal fluid is detected by liquidchromatography/mass spectrometry/mass spectrometry (HPLC-MS/MS).Results:(1) The rats death in Experiments: Four rats died by gavage,three rats death died in experiments because of cardiac arrest and apnea.(2) The neurological behavior score: The neurological behavior score ofall rats before cerebral ischemia are normal (p>0.05);1h afterreperfusion, the score of sham group is higher than saline and vaccinegroup (P<0.01);24h after reperfusion, the score of sham group is higherthan saline and vaccine group (P<0.01), the score of saline group ishigher than vaccine group (P<0.05).(3) The neuronal densities:24h afterreperfusion, the neuronal densities of saline and vaccine group are bothlower than sham group (P<0.01), the neuronal densities of saline group islower than vaccine group (P<0.01);48h after reperfusion, the neuronaldensities of saline and vaccine group are both lower than sham group(P<0.01), the neuronal densities of saline group is lower than vaccinegroup (P<0.05);72h after reperfusion, the neuronal densities of saline group is lower than sham and vaccine group (P<0.01).(4) Theconcentration of glutamic acid:24h after reperfusion, the concentration ofglutamic acid in saline and vaccine group are both higher than shamgroup (P<0.01), vaccine group is higher than saline group (P<0.01);48hafter reperfusion, the concentration of glutamic acid in saline and vaccinegroup are both higher than sham group (P<0.01);72h after reperfusion,the concentration of glutamic acid in saline group is higher than sham andvaccine group (P<0.01).Conclusion:(1) After cerebral ischemia and reperfusion in rats model,the concentration of glutamic acid was increased obviously at24h, thenmarkedly reduced at48h, eventually heightened at72h again.(2) NR1/TFR chimeric epitope vaccine could produce the protectiveeffect on cerebral ischemia and reperfusion injury in rats, but the specificmechanisms could need to research further.