Stellate Ganglion Block Attenuates Cardiopulmonary Bypass-induced Cerebral Injury In Rat

Objective To establish cardiopulmonary bypass and stellate ganglion blockmodel in rats, and to investigate the effect of stellate ganglion block withbupivacaine on caspase-3gene expression in hippocampi of the rat aftercardiopulmonary bypass (CPB).Methods Forty adult male Sprague-Dawley(SD) rats were randomlyallocated to four groups. Group RC (n=10) underwent right sided stellateganglion block(SGB)with bupivacaine and cardiopulmonary bypass(CPB) for60minutes, Group C (n=10) underwent CPB only for60minutes (min),GroupR(n=10) underwent right sided SGB with0.25%bupivacaine. Group S(n=10)sham groups did not undergo SGB and CPB. All animals were anesthetized(350mg·kg-1of chloraldurat for intramuscular), ware cannulated， orallyintubated and mechanically ventilated. The rats in RC group and C groupconnected to CPB underwent CPB for60minutes. The rat of S group and Rgroup were monitored for four hours after vane and artery was cannulated.During the procedure, rats haemodynamical parameters, body-temperature (T) were monitored, while arterial blood gas,electrolytes and hemodilutionparameters were analyzed. The hippocampus tissue was collected afterexperiment. Immunohistochemistry staining were used to detect proteinexpressions of caspase-3in hippocampus tissue. Hippocampal caspase-3mRNAexpressions were determined with reverse transcriptase polymerase chainreaction (RT-PCR) method. Electron microscopy was used to observe theultrastructure of the hippocampus.Results The CPB and SGB model was successfully established in rats.Expression of caspase-3mRNA and protein increased at the C and RC group thatunderwent cardiopulmonary bypass, compare with the S group (P<0.05).Theexpression of caspsase-3mRNA and protein at RC group was lower than Cgroup,SGB can reduced the caspsase-3mRNA and protein expression afterCPB(P<0.05). After CPB the ultrastructure of the hippocampus was damaged.The damage degree of ultrastructure of hippocampus in RC group wassignificantly reduced than C group.Conclusion The SGB and CPB model of rat is an effective model toinvestigate physiological mechanism of SGB and pathophysiologicalmechanism of CPB related injury. Stellate ganglion block attenuate CPBinduced cerebral injury by suppressing the expression of caspase-3gene inhippocampi after cardiopulmonary bypass．...