目的:研究二氮嗪(diazoxide,DZ)预处理对H2O2损伤L6骨骼肌成肌细胞(skeletal myoblast,SKM)的保护作用,并探讨其与磷脂酰肌醇3激酶(phosphatidylinositol-3 kinase,PI3K)/Akt信号通路的关系。方法:体外培养的L6 Sk Ms随机分为4组:对照组、H2O2损伤组(H2O2group;0.40mmo1/L H2O2作用24h),DZ预处理组(DZ group;200μmol/L DZ预处理30 min后,0.40mmo1/L H2O2作用24 h),LY294002抑制剂组(LY group;200μmol/L DZ和50μmol/L LY294002共同孵育30 min后,0.40mmo1/L H2O2作用24 h)。采用MTT比色法检测各组细胞存活率;Annexin V-FITC/PI流式细胞术检测各组细胞凋亡率;Western blotting法检测各组细胞P-Akt、Caspase-3、Caspase-9的表达水平。结果:与对照组相比,H2O2损伤可诱导细胞凋亡,显著降低细胞存活率,降低P-Akt蛋白表达而增加Caspase-3,9蛋白表达。与H2O2组比较,DZ组的细胞存活率显著上升,凋亡率显著下降,P-Akt蛋白表达明显增加而Caspase-3,9表达明显降低。而PI3K抑制剂LY294002能够显著抑制DZ预处理对细胞的保护和抗凋亡作用,同时使P-Akt蛋白表达显著降低,Caspase-3,9蛋白表达显著增加。结论:DZ预处理可激活PI3K/Akt信号通路,下调凋亡蛋白caspase-3,9,从而抑制H2O2引起的L6 SKMs的凋亡。 OBJECTIVE: To investigate the protective effect of diazoxide (DZ) preconditioning on skeletal myoblast (SKM) induced by H2O2 injury and its relationship with phosphatidylinositol 3 kinase (PI3K) / Akt signaling pathway. Methods: L6 Sk Ms cultured in vitro were randomly divided into four groups: control group, H2O2 group (H2O2group; 0.40mmo1 / L H2O2 for 24h), DZ group (200μmol / L DZ pretreatment for 30min, 0.40mmo1 / L H2O2 for 24 h), LY294002 inhibitor group (LY group; 200μmol / L DZ and 50μmol / L LY294002 incubated for 30 min, 0.40mmo1 / L H2O2 for 24 h). The cell viability was measured by MTT assay. The apoptosis rate of each group was detected by Annexin V-FITC / PI flow cytometry. The expressions of P-Akt, Caspase-3 and Caspase-9 were detected by Western blotting Level. Results: Compared with the control group, H2O2 injury induced cell apoptosis, significantly decreased cell viability, decreased P-Akt protein expression and increased Caspase-3, 9 protein expression. Compared with H2O2 group, the cell survival rate of DZ group was significantly increased, the apoptosis rate was significantly decreased, P-Akt protein expression was significantly increased and Caspase-3, 9 expression was significantly reduced. The PI3K inhibitor LY294002 could significantly inhibit the protective effect of DZ preconditioning on cells and anti-apoptotic effect, at the same time, the expression of P-Akt protein was significantly decreased and the expression of Caspase-3, 9 protein was significantly increased. Conclusion: DZ pretreatment can activate PI3K / Akt signaling pathway and down-regulate the expression of caspase-3 and 9, thereby inhibiting the apoptosis of L6 SKMs induced by H2O2.