The Effect And Mechanism Of Transection Of The Cervical Sympathetic Trunk In Reducing Cerebral Ischemia-reperfusion Injury In Rats

BackgroundIschemia is a common cause of stroke,and brain injury caused by ischemia-reperfusion is the main reason for the poor clinical prognosis of stroke patients.The current main clinical treatment methods show disadvantages in acute stroke management.Stellate Ganglion Block（SGB）has been widely used in a variety of clinical diseases,and has shown good efficacy in recent years.The rat of Transection of the cervical sympathetic trunk（TCST）is considered to be a satisfactory animal model to simulate long-term human SGB [1].Our previous study found that TCST can alleviate cerebral ischemia-reperfusion injury（CI/R）,but the underlying mechanism is unknown.ObjectiveThe purpose of this study was to investigate the effect and mechanism of cervical sympathetic nerve dissection on cerebral ischemia-reperfusion injury.MethodsThirty male SD rats were randomly divided into three groups: sham operation group（Sham group）,cerebral ischemia-reperfusion group（I/R group）,I/R group + TCST group（TCST group）,10 rats in each group.Only the blood vessels were exposed in the Sham group,and the remaining two groups were reperfused for 24 hours after the middle cerebral artery was blocked for 90 minutes.The left sympathetic nerve was cut off in the TCST group after reperfusion.The neurological function of the rats was evaluated after 24 hours,the volume of cerebral infarction was detected by 2% 2-3-5-triphenyltetrazolium chloride（TTC）,the expression of serum TNF-α was detected by Elisa method,and the Western blot（WB）experiment was used to detect Expression of TLR4,Caspase3,cleaved-caspase-3,IL-6,IL-1β protein.Results1.The neurological function of the rats in the Sham group was normal,and there was no brain infarction;compared with the Sham group,the I/R group had higher neurological function scores and increased cerebral infarction volume（P < 0.05）;the TCST group had higher neurological function scores and cerebral infarction volumes than I/R group decreased（P < 0.05）.2.Elisa analysis showed that the expression of serum inflammatory factors:Compared with the Sham group,the expression of TNF-α in the I/R group was increased（P< 0.05）;compared with the I/R group,the expression of TNF-α in the TCST group was decreased（P < 0.05）.3.Western blot analysis of protein expression: Compared with Sham group,the expression of TLR4,Caspase3,cleaved-caspase3,IL-6,IL-1β protein in I/R group increased（P < 0.05）;The protein expressions of TLR4,Caspase3,cleaved-caspase3,IL-6 and IL-1βwere decreased in TCST group（P < 0.05）.ConclusionTCST can reduce the inflammatory response and brain injury caused by CI/R,and the protective effect of TCST may be related to the reduction of TLR4.