Influence Of Tanshinone â…¡A On The Expression Of Brain N-methyl-D-aspartate Acid Receptor1(NMDAR1) In Rats After Cardiopulmonary Resuscitation And Its Brain Function Protection

Objective:To investigate the influence of Tanshinone ⅡA on the expression of brainN-methyl-D-aspartate acid receptor1(NMDAR1) protein in rats after cardiopulm-onary resuscitation and its brain function protectionMethods:78SD male rats were randomly divided into three groups:group A (sham group，n=6)，group B (control group，n=36) and group C (Tanshinone ⅡA interventiongroup，n=36). All animals were induced cardiac arrest by choking models. Thegroup C rats received intravenous injection of Tanshinone ⅡA15mg/kg at recoveryinstantly，While group B rats were intravenous injected same amount of normal saline.Changes of mean arterial pressure(MAP) was monitored within60minutes in groupA after the surgery,the sane index in group B and C was measured after restorationof spontaneous circulation(ROSC).Brains were decapitated at1h、6h、12h、24h、48h and72h after ROSC. immunohistochemical staining method was applied forbrain tissue NMDAR1、 aquaporin-4(AQP4) and Cysteiny laspartate specificproteinase-3(Caspases-3) expression test，while water content of the brain wasmeasured by wet and dry weight therapy. SPSS17.0software was used for Statisticalanalysis. The experimental results is compared between groups using one-wayANOVA,Statistical differences were considered significant when p <0.05.Results:①The weight、respiration、heart rate in basic condition and the changes of MAPwere no significant difference between groups (P>0.05).②Brain NMDAR1protein expression in group B increased at1h and reachedits peak at6h after ROSC, then its expression decreased and dropped below normal at 48h、72h，with a significant difference compared with the group A (P <0.05)；NMDAR1protein expression at1h、6h、12h in Group C was significantly lowerthan that in Group B at the same point in time (P <0.01), but no significant differencewas seen at24h、48h、72h (P>0.05).③Brain Caspases-3expression in group B increased after ROSC，and reachedits peak at48h after ROSC, then decreased and maintained above normal at72h,with a significant difference compared with the group A (P <0.01); Group C1h、6h、12h、24h was significantly lower than that in group B (P <0.01),48h、72h expre-ssion level is also lower (P <0.05).④Brain AQP4expression in group B increased at1h and reached its peak at24h after ROSC，then gradually decreased at48h，but maintain above normal at72h，with a significant difference compared with the group A (P<0.01or P <0.05);compared with B group,the expression of AQP4was decreased significantly at6h、24h、48h、72h in C group(P<0.01),1h、12hexpression level is also lower(P <0.05).⑤Brain brain tissue water content in group B increased at1h and reached itspeak at24h after ROSC，then gradually decreased at48h, but maintain above normalat72h，with a significant difference compared with the group A (P<0.01or P <0.05)；compared with B group，C group water content decreased significantly (P<0.01).Conclusions:1.The expression of Caspases-3、 AQP4and brain edema was increasedsignificantly ar1h after ROSC,the heaviest brain damage at24h and48h,but72h isstill nor back to normal.2.Brain NMDAR1protein expression increased at1h and reached its peak at6hafter ROSC,NMDA receptors were involved in early brain injury mediatedprocess.the expression of NMDAR1gradually decline from12h and lower thannormal in48h,but Caspases-3、AQP4expression are still in the peak at48h, whetherlow expression of NMDA receptors associated with brain injury in the laterexperiment is unclear.3.Tanshinone Ⅱ A down-regulates brain NMDAR1protein at early stage in rats as well as significantly inhibits the expression of Caspases-3and brain edema aftercardiopulmonary resuscitation.