Effect of fluctuant high glucose to pancreatic β-Cell lines INS-1 / 中华胰腺病杂志

ABSTRACT

Objective To investigate the damage mechanism of fluetuant high glucose on the INS-1 cells (pancreatic β-cell lines).Methods The cells were divided into five groupsthe control groups (A group5.5 mmol/L of glucose),the continuing high glucose group (B group16.7 mmoL/L of glucose),the fluctuant glucose group ( C group16.7 mmol/L of glucose for cultivation for 2 h,then the concentration changed to 5.5 mmol/L for cultivation for 3 h,which was repeated 3 times per day;the ceils were kept in the medium containing 5.5 mmol/L of glucose during night time for 9 h),the continuing high glucose plus NAC ( 1.0 mmo/L) group ( D group),the fluctuant glucose plus NAC group ( E group).The intracellular reactive oxygen species (ROS) was observed by the flow cytometry.The activity of glucose-6-phosphate dehydrogenase (G6PD) was estimated by the tetrazolium linked cytochemical method.Results 72 h after intervention,the levels of ROSwere 37.77±2.31,86.97±7.97,124.27±10.04,60.92±2.61 and 51.47±3.36,respectively,in A～E group;the activities of G6PD were 1.25±0.03,1.09±0.02,1.03±0.01,1.12±0.02 and 1.21±0.01,respectively;the levels of NADPH were (0.123±0.003) mmol/mg prot,(0.112±0.004) mmoL/mg prot,(0.099±0.002 ) mmol/mg prot,( 0.116±0.005 ) mmol/mg prot and ( 0.120±0.002) mmol/mg prot,respectively.The level of ROS in the cells of the fluctuant glucose group were significantly higher than that in the continuing high glucose group ( P ＜ 0.01 ).The G6PD activity and NADPH was significantly lower in fluctuant high glucose group than those in the continuing high glucose group (P ＜0.01 ).NAC co-cultivation decreased the extent of cell's change.Conclusions Exposure of INS-1 to high glucose lead to increased oxidative stress, possible mechanism included decreased G6PD activity and subsequent imbalance between oxidation and reduction.