The Role Of PI3K/Akt/GSK-3? Pathway In Lipid Emulsion To Reverse The Hippocampal Neurons Cytotoxicity Induced By Bupivacaine In Rats

Objective To investigate whether lipid emulsion reverses the hippocampal neurons cytotoxicity induced by bupivacaine through the regulation of PI3K/Akt/GSK-3? signaling pathway in rat,and to clarify the possible mechanism of lipid emulsion in the treatment of bupivacaine-induced neurotoxicity.Methods SD rat hippocampal neurons primary cultured in vitro were divided into 6groups : The blank control group(Ctrl group),Bupivacaine group(BPV group),Lipid emulsion group(LE group),Bupivacaine + lipid emulsion group(BPV + LE group),Bupivacaine + lipid emulsion + PI3K/Akt inhibitor group(BPV + LE + LY294002 group),Bupivacaine + lipid emulsion + GSK-3? inhibitor group(BPV + LE + SB216763 group).After the cells were treated for 24 h,cell viability was measured by CCK-8 method.Western blot was used to detect the expression of protein pAkt/Akt,pGSK-3?/GSK-3? and Cleaved caspase-3.The changes of action potential were detected by electrophysiological patch clamp technique.Nissl staining was used to observe the intracellular nissl body and cells growth state under light microscope.Results 1.Comparison of cell viability of hippocampal neurons in each group:compared with group Control,the cell viability of BPV group,BPV + LE group,BPV + LE +LY294002 group and BPV + LE + SB216763 group were decreased.Compared with group BPV,the cell viability of LE group,BPV + LE group and BPV + LE + SB216763 group wereincreased.Compared with group BPV + LE,the cell viability of BPV + LE + LY294002 group was decreased.All the differences were statistically significant(P < 0.05).2.Comparison of the expression of protein pAkt/Akt,pGSK-3?/GSK-3? and Cleaved caspase-3 of hippocampal neurons in each group: compared with group Control,the expression of protein pAkt/Akt was decreased in BPV group,LE group,BPV + LE group and BPV + LE + LY294002 group,the expression of protein pGSK-3?/GSK-3? was decreased in BPV group,LE group,BPV + LE group,BPV + LE + LY294002 group and BPV + LE +SB216763 group,while the expression of protein Cleaved caspase-3 was increased in BPV group,BPV + LE group,BPV + LE + LY294002 group and BPV + LE + SB216763 group.These differences were statistically significant(P < 0.05).Compared with group BPV,the expression of protein pAkt/Akt was increased in LE group,BPV + LE group and BPV + LE +SB216763 group,while the expression of protein pGSK-3?/GSK-3? and Cleaved caspase-3were decreased in LE group,BPV + LE group,BPV + LE + LY294002 group and BPV + LE+ SB216763 group.These differences were statistically significant(P < 0.05).Compared with group BPV + LE,the expression of protein pAkt/Akt was decreased in BPV + LE +LY294002 group and increased in BPV + LE + SB216763 group,the expression of protein pGSK-3?/GSK-3? and Cleaved caspase-3 were decreased in BPV + LE + SB216763 group.All the differences were statistically significant(P < 0.05).3.Comparison of action potential of hippocampal neurons in each group: compared with group Control,the action potential duration was increased while the number was decreased in BPV group.Compared with group BPV,the action potential duration was shortened and the number was increased in BPV + LE group.These differences were statistically significant(P< 0.05).The difference was not statistically significant in other indexes of action potential between groups(P >0.05).Conclusion Lipid emulsion may reduce the effect of bupivacaine on apoptosis andaction potential of hippocampal neurons by regulating PI3K/Akt/GSK-3? pathway,so as to reverse the cytotoxicity of hippocampal neurons induced by bupivacaine in rats.