Effects Of Stellate Ganglion Block On Wnt5a/Ca²⁺signaling Pathway And Inflammatory Response In Rats During Cardiopulmonary Bypass

Objective: Optimize modeling method of rat beating-heart cardiopulmonary bypass and SGB,and explore the protective mechanism of stellate ganglion block on brain injury during cardiopulmonary bypass in rats.and whether it is associated with Wnt5a/Ca2+ signaling pathway and inflammatory response.Methods: Grouping 64 healthy male SD rats into four groups by random number table method: sham group(group B),CPB group(group C),stellate ganglion block group(group S),and stellate ganglion block plus cardiopulmonary bypass group(group SC).A rat model of beating-heart cardiopulmonary bypass was established by connecting the right external jugular vein and the right femoral artery with cannulation,then connecting them with an CPB machine,an animal membrane lung,and some relative pipelines to make them a loop.Anterior approach with ropivacaine to establisha rat stellate ganglion block model,with Horner syndrome as a success sign.After the corresponding operation,Group B and group S were observed for two hours while group C and SC were subjected to extracorporeal circulation for 2hours.Serum samples were obtained immediately after the start of the experiment(T0),1 hour after the start of the experiment(T1),and 2 hours after the start of the experiment(T2);Each group of rats were sacrificed by excessive anesthesia,then take these brains.Elisa method was used to detect plasma IL-6and IL-10 concentrations at various time points.Western blot was used to detect the expression of Wnt5 a,p-Ca MK?,PKC and NF-?B in hippocampus.The m RNA expression of Wnt5 a,frizzled-2,p-Ca MKII and NF-?B in hippocampus were detected by real-time PCR.Results: There were no significant differences between the group B and group S(P > 0.05).Compared with the group B,the concentrations of plasma IL-6 and IL-10 in the group C and group SC at the T1 and T2 time points has a significant increase(P <0.05),and the concentration in T2 was higher than T1(P <0.05).Compared with the group C,the plasma IL-6 concentration in the group SC decreased at T1 and T2(P < 0.05).IL-10 plasma concentration increased at T1 and T2(P < 0.05).Compared with group B,the protein expression of Wnt5 a,p-Ca MKII,PKC and NF-?B in hippocampus of group C and SC were significantly increased(P <0.05),Compared with group C,the expression of Wnt5 a,p-Ca MKII,and PKC in hippocampal neurons were decreased(P < 0.05),while the expression of NF-?B was not significantlydifferent(P > 0.05).Compared with group B,the m RNA expression of Wnt5 a,frizzled-2,p-Ca MKII and NF-?B in hippocampal neurons of group C and SC were significantly increased(P <0.05).Compared with group C,the m RNA expression of hippocampal neurons of Wnt5 a,frizzled-2,p-Ca MKII and NF-?B were significantly decreased(P <0.05).Conclusion: Cardiopulmonary bypass can increase plasma inflammatory factors and the expression of related proteins in the Wnt5a/Ca2+ signaling pathway in hippocampus,these are associated with brain damage in rats.Stellate ganglion block can effectively alleviate the severity of brain injury after cardiopulmonary bypass in rats,and its protective effect may be related to inhibition of Wnt5a/Ca2+ pathway,reduction of neuronal calcium overload and inhibition of inflammatory response.