Acute blood glucose fluctuation induces myocardial apoptosis through oxidative stress and nuclear factor-ĸB activation

Objective: It was the aim of this study to investigate whether acute blood glucose fluctuation induces myocardial apoptosis and to examine the potential mechanisms.

Methods: 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.

Results: 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.

Conclusion: Acute blood glucose fluctuation induces myocardial apoptosis, apparently associated with enhanced oxidative stress and activation of NF-ĸB.