Acute Blood Glucose Fluctuation Induces Myocardial Apoptosis through Oxidative Stress and Nuclear Factor-ĸB Activation

Abstract

It was the aim of this study to investigate whether acute blood glucose fluctuation induces myocardial apoptosis and to examine the potential mechanisms. Wistar rats were infused intermittently or continually with 50% glucose solution for 48 h. Serum and myocardium were taken to measure the levels of malondialdehyde and glutathione peroxidase. The expression of nuclear factor (NF)-ĸB and apoptosis in myocardial cells was determined with immunohistochemisty and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Expressions of B-cell lymphoma/leukemia-2-associated X protein and B-cell lymphoma/leukemia 2 in myocardium were tested with Western blot analysis. The levels of malondialdehyde and B-cell lymphoma/leukemia-2-associated X protein in the acute blood glucose fluctuation group (AFG) were enhanced, but glutathione peroxidase and B-cell lymphoma/leukemia-2 were reduced compared with levels in the continually high blood glucose group (p < 0.05). The expression of NF-ĸB in the nuclei of myocardial cells in the AFG was significantly higher than that in the continually high blood glucose group (p < 0.05). Apoptotic myocytes were observed in myocardium of the AFG. Acute blood glucose fluctuation induces myocardial apoptosis, apparently associated with enhanced oxidative stress and activation of NF-ĸB.