【摘要】 目的研究左旋精氨酸/一氧化氮通路对胰岛β细胞凋亡的影响,初步探讨一氧化氮(NO)诱导胰岛β细胞凋亡的作用。方法体外培养的NIT-1小鼠胰岛β细胞,用不同浓度的L-精氨酸(L-arg)处理,6h后采用Griess化学显色法检测细胞培养液内的NO水平,Annexin-V/PI双染流式细胞术检测细胞的凋亡。而后联合应用hemoglobin处理细胞,分为3组:对照组;L-arg组;L-arg+hemoglobin组;6h后检测NO的水平和细胞的凋亡,并用Western Blot检测P53蛋白的表达。结果与对照组比较,L-arg4mg/mL处理组的NO水平最高(P<0.05),细胞凋亡最明显(P<0.05);hemoglobin干预后,NO水平和细胞凋亡率均较L-arg单独处理组明显降低(P<0.05),与正常对照组之间差异没有显著性(P>0.05);Western Blot提示L-arg组的P53蛋白的表达水平明显高于对照组和hemoglobin处理组(P<0.05)。结论L-arg/NO通路可诱导NIT-1小鼠胰岛β细胞凋亡,并呈现一定程度的剂量依赖性;NO可能通过P53的活化诱导NIT-1胰岛细胞凋亡。更多还原

【Abstract】 [Objective] To investigate the effect of L-arginine/Nitric Oxide pathway on apoptosis of pancreatic β-cell and to study the potential mechanism of apoptosis in islet cell induced by Nitric Oxide (NO). [Methods] After the exposure of NIT-1 murine pancreatic β-cells to L-arginine (L-arg) at various concentrations for six hours, NO levels were measured by Griess reagent assay and the cells apoptosis were measured by flow cytometry. Next, treated with hemoglobin, cells were divided into three groups: control group; L-arg group; L-arg + hemoglobin group, then the above same points were detected and the P53 protein level were detected by western blot. [Results] NO level and apoptosis percentage achieved to max (P <0.05) at the concentration of 4 mg/mL, compared with the control group. After treated with hemoglobin, NO level and apoptosis percentage were significantly inhibited (P <0.05) compared with the L-arg group, while not different (P >0.05) compared with the control group. Western Blot indicated that P53 protein level of L-arg group significantly increased, compared with that of control group and hemoglobin group (P <0.05). [Conclusion] L-arg/NO pathway induces the apoptosis of NIT-1 murine pancreatic β-cells in a dose-dependent manner. The mechanisms that NO induces apoptosis in NIT-1 murine pancreatic β-cell may be associated with P53 activation.更多还原