Effect Of Sevoflurane Preconditioning On TLR9/NF-κB Signaling Pathway After Cardiopulmonary Bypass In Rats Brain

Objective: To evaluate the role of TLR9 /NF-κB signaling pathway in Sevoflurane preconditioning against during CPB brain injury in rats and investigate the relationship between TLR9 signaling pathway and apoptosis.Methods: Select forty male SD rats weighting of 350 ~ 450 g, using cardiopulmonary bypass model without blood preshoot prepared rats were randomly divided into sham operated group(group S), CPB group( group C), SEV pretreatment + CPB group(group E) and SEV pretreatment + TLR9 signaling pathway inhibitor Cp G ODN 2088 + CPB group(group F), 10 in each group.Pretreatment method for inhalation of 2.4% sevoflurane 1h, oxygen elution 30 min after establish CPB model 1h. Respectively( CPB instantly) T0,( CPB 30min) T1,( stop CPB instantly) T2,( after CPB 1h) T3,( after CPB 2h) T4,( after CPB 3h) T5,serum samples were collected, ELISA was used to detect the concentration of serum S100-β. Hippocampus neuron apoptosis were counted by TUNEL-immunofluorescence assay, iummunohistochemistry stain was used to determine the expressions of NF-κB. Western blotting method to detect brain tissue TLR9 and NF-κB(p65) protein expression levels.Results:1.The rat at each time point in HR, MAP, rectal temperature and arterial blood gas analysis results HR, and MAP after began to bypass obviously reduced(T0 compared, P <0.05), to stopped turned flow 1h began recovery(T0 compared, P>0.05); T turned flow during maintained 32 ℃ ~34 ℃; p H value basic keep stable; Pa CO2,and Pa O2 in turned flow before and after more stable(P>0.05); Hct turned after flow began declined(P <0.05); in turned flow during K+ concentration keep stable(P >0.05). 2.TUNEL detection of apoptosis of hippocampal neuronscompared with the groups IA, IA values for C and E and F group increased(P <0.05); compared with C, E and E group IA values decrease(P<0.05);compared with group E, group FIA value reduction( P <0.05) 3. S100-β in rats at different time points in each group of beta ELISA test results compared with the group S, C and E and F group T1~5 elevated serum S100-β concentrations of(P<0.05), compared with the C group, group E, F T1~5serum S100-β concentrations of reduction(P <0.05); compared with group E,group F T1~5 serum S100-β concentrations of reduction(P <0.05). 4. Western-blot detection of NF-κB(p65) in the hippocampus of rats in each group and S group compared, C group and E, and F group hippocampus organization NF-κB(p65) protein expression are significantly increased(P<0.05); and C group compared, E, and F group hippocampus organization NF-κB(p65) protein expression significantly reduced(P<0.05); and E group compared, F group hippocampus organization NF-κB(p65) protein expression increased(P<0.05). 5. Western-blot detection of TLR9 protein in hippocampus of rats in each group compared with the group S, C and e and F group expression of TLR9 was significantly increased in the hippocampus(P <0.05); and group C, E and F group was significantly reduced in the hippocampus(P<0.05); compared with group E, group F hippocampus increased theexpression of TLR9(P <0.05).Conclusins: 1.TLR9/NF-κB signaling pathways in the regulation of brain injuriedduring cardiopulm-onary bypass. 2.Sevoflurane preconditioning may activate the NF-κB in advance through damping TLR9/NF-κB signaling pathway activation induced damage tolerance of the rats after cardiopulmonary bypass.