Effects of intermittent high glucose on oxidative stress in endothelial cells

The objective of this study is to explore the mechanism of oxidative stress induced by intermittent high glucose in porcine iliac endothelial cells (PIECs). The PIECs were exposed to intermittent or constant high glucose for 3 or 6 days, and the mean fluorescent intensity (MFI) was measured via intracellular reactive oxygen species (ROS) captured by flow cytometry. The NADPH oxidase activity was measured by chemiluminescence with lucigenin. Intermittent high glucose induced a greater over-production of ROS than constant high glucose in PIECs; the NADPH oxidase activity was increased under both constant and intermittent high glucose conditions, being more marked in the latter (P < 0.05). In conclusion, intermittent high glucose induced more ROS in PIECs than constant high glucose, this effect seemed to be, at least in part related to the enhanced activation of NADPH oxidase. Glucose fluctuation may be involved in the development of vascular complications.