间断高浓度葡萄糖对胰岛β细胞的损伤机制研究  

Damage Mechanism of Intermittent Exposure to High Concentrations of Glucose to β Cell Lines(HIT-T15 cell)

作　　者：邱平[1] 赵铁耘[1] 李秀钧[1] 刘述益[1] 李小玉[2] 

机构地区：[1]四川大学华西医院内分泌科,成都610041 [2]四川大学华西口腔医学院生物实验室

出　　处：《四川大学学报（医学版）》2008年第1期69-71,93,共4页Journal of Sichuan University(Medical Sciences)

摘　　要：目的探讨间断高浓度葡萄糖对培养的胰岛β细胞(HIT-T15细胞)的损伤机制。方法实验分为对照组(葡萄糖5.5mmol/L)、持续高浓度葡萄糖组(葡萄糖16.7mmol/L)、间断高浓度葡萄糖组(葡萄糖16.7mmol/L培养2h后更换为5.5mmol/L的葡萄糖3h,每天重复共3次,夜间9h维持在5.5mmol/L的培养基中)、抗氧化剂(NAC1.0mmol/L)+持续高糖组和NAC+间断高糖组。放免法测定胰岛素分泌水平;罗丹明123染色线粒体,激光共聚焦显微镜测量线粒体膜电位(MMP);荧光素酶方法检测细胞内ATP含量;硫代巴比妥酸法测量脂质过氧化物丙二醛(MDA)水平;流式细胞仪测定活性氧簇(ROS)的水平。结果高糖刺激后胰岛素分泌量在间断高糖组〔(3.13±1.11)μIU/mL〕和持续高糖组〔(5.18±0.95)μIU/mL〕分别较对照组〔(9.33±0.62)μIU/mL〕均明显减少(P<0.05);MDA水平、ROS水平明显升高(P均<0.05),并且间断高糖组较持续高糖组产生更多的ROS(P<0.05);间断高糖组和持续高糖组细胞内ATP含量、MMP水平明显降低(P<0.05或P<0.01)。结论间断高浓度葡萄糖与持续高糖均使培养的β细胞线粒体氧化应激水平增高,且间断高糖组较持续高糖组产生更严重的氧化应激,从而使β细胞分泌胰岛素功能受损,其机制可能是由于氧化应激使线粒体的膜电位下降,细胞ATP含量减少所致。Objective To test the effect of intermittent exposure to high concentrations of glucose on HIT- T15 cells. Methods The HIT-T15 cells （pancreatic βcell lines） were exposed to 16.7 mmol/L of glucose for two hours, at an interval of three hours. Such intermittent exposure was repeated three times a day. Otherwise, the cells were exposed to 5.5 mmol/L of glucose. The control groups included continuing exposure to 5.5 mmol/L of glucose （normal control group） and continuing exposure to 16.7 mmol/L of glucose. The impact of N-acetyl-L- cysteine （NAC） was also tested in the groups with intermittent and continuing exposure to 16. 7 mmol/L of glucose. The insulin was detected by radioimmunoassay （RIA）. The mitochondrial membrane potential （MMP） was measured by laser scanning confocal microscope. The ATP levels of β cells were examined by the luciferinluclferase kit. The Malonaldehyde （MDA） was measured through thiobarbituric acid reaction （TBA）. The intracellular reactive oxygen species （ROS） was observed by flow cytometry. Results The HIT-T15 cells exposed to intermittent and continuing high glucose secreted C（3.13±1.11） μIU/mL] and C（5.18±0. 95） μIU/mL] of insulin, significantly less than the control [（9. 33μ0. 62） μIU/mL, P〈0. 053. The MDA and ROS levels increased while the ATP and MMP levels decreased significantly in the cells exposed to intermittent and continuing high glucose （P〈0.05）. The cells exposed to intermittent high glucose produced more ROS than the cells exposed to continuing high glucose （P〈0.05）. Conclusion Exposure of HIT-T15 to high glucose leads to oxidative stress of mitochondrial. Intermittent exposure causes more serious stress than continuing exposure. Such response might be a result of decreased MMP level and ATP contents.

关 键 词：间断高浓度葡萄糖 Β细胞 氧化应激 

分 类 号：R587.1[医药卫生—内分泌]