AIM: To investigate the effect of intermittent hypoxia on the apoptosis of mouse pancreatic β cells and its possible mechanism.METHODS: Thirty healthy male C57BL/6J mice were randomly divided into 3 groups: control group, sustained hypoxia ( SH )group and intermittent hypoxia ( IH )group.Insulin tolerance test was performed immediately after experiment.The level of malondialdehyde ( MDA ) and superoxide dismutase ( SOD ) were detected by chemical colorimetry.Real - time PCR was used to measure the mRNA expression of manganese superoxide dismutase( MnSOD ) and glutathione peroxidase( GPx1 ).The apoptosis of pancreatic β cells was determined by the method of TUNEL.RESULTS : The levels of insulin resistance and content of MDA in the pancreatic tissue in IH group were significantly higher than those in control group and SH group ( P ＜0.01 ).The activity of SOD and the mRNA expression of MnSOD and GPx1 in IH group were significantly lower than those in control group and SH group ( P ＜0.01 ).The apoptotic rate of IH group was significantly elevated as compared with control group and SH group ( P ＜0.01 ).No significant difference of all above indexes between control group and SH groups was observed ( all P ＞0.05 ).CONCLUSION: Apoptosis of pancreatic β cells induced by oxidative stress associated with IH in the pancreatic tissue may be involved in the pathogenesis of obstructive sleep apnea hyponea syndrome with insulin resistance and type 2 diabetes.%目的:探讨间歇低氧对小鼠胰腺β细胞凋亡的影响及其可能机制.方法:将30只雄性C57BL/6J小鼠随机分为间歇低氧组、持续低氧组和正常对照组,每组10只.实验结束后测定各组小鼠的胰岛素耐量;采用化学比色法测定胰腺组织丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性;用real-time PCR检测小鼠胰腺组织中锰超氧化物歧化酶(MnSOD)和谷胱甘肽过氧化酶(GPx1) mRNA的表达水平;并用TUNEL染色检测胰腺β细胞凋亡.结果:间歇低氧组小鼠胰岛素抵抗水平及胰腺组织中MDA水平显著高于正常对照组和持续低氧组 (P<0.01);胰腺组织SOD活性显著低于正常对照组和持续低氧组(P<0.01);抗氧化酶MnSOD和GPx1 mRNA的表达水平显著低于正常对照组和持续低氧组 (P<0.01);而胰腺β细胞凋亡率显著高于正常对照组和持续低氧组(P<0.01).持续低氧组与正常对照组上述各种指标的比较均无显著差异(均P＞0.05).结论:间歇低氧可导致胰腺组织氧化应激状态和胰腺β细胞凋亡,这可能是阻塞性睡眠呼吸暂停低通气综合征患者胰岛素抵抗及2型糖尿病的病理生理基础之一.
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