Immunologic effects of acute hyperglycemia in nondiabetic rats

Background: This study was designed to determine the consequences of acute hyperglycemia on the immune function of peripheral neutrophils, peritoneal macrophages, and alveolar macrophages in nondiabetic rats. Methods: The animals were randomly divided into nonsurgical (normal) and surgical groups. The postoperative rats were further divided into normoglycemic (control) and hyperglycemic (glucose) groups. The hyperglycemic condition was maintained by constant infusion of glucose to raise plasma glucose concentration to 300 mg/dL for 3 hours. The immune cells were then harvested to determine their phagocytic and oxidative capacities via flow cytometry. Results: The results showed that hyperglycemia significantly decreased the respiratory burst of alveolar macrophages (p < .05). In contrast, hyperglycemia enhanced phagocytosis in these cells (p < .002). There was a significant activation of the respiratory burst in peripheral neutrophils by surgery (p < .002), but no effect of hyperglycemia. Conclusions: We conclude that hyperglycemia itself can influence immune function in some phagocytic cells, which may be an important factor in postsurgical infection.