Effects of rhG-CSF on neutrophil functions and bone marrow parameters in diabetic rats

Neutrophils have an important role in the host defense. The elevated serum glucose levels of diabetics affect traditional host defenses such as neutrophil counts and functions. The causes of these impairments are not clear. We aimed to investigate changes of peripheral neutrophil counts and functions and their relation with bone marrow cells in diabetic rats. Thirty-two rats were divided into four equal groups. Group 1 were controls and Groups 2 and 4 were made diabetic by a single intraperitoneal injection of streptozotocin. Granulocyte colony stimulating factor (G-CSF) was injected subcutaneously into Groups 3 and 4. White blood cell count, neutrophil counts and function and bone marrow cell count were determined. Peripheral blood cell counts, neutrophil phagocytosis index were decreased but neutrophil adhesivity index was not different in the diabetes-induced group. There was a difference in circulating white blood cell counts and neutrophil counts between the rhG-CSF treated and non-treated groups. The phagocytosis index of neutrophil in diabetic rats was significantly diminished by rhG-CSF treatment. A hyperplasia of early cells of the myeloid series in G-CSF treated groups was observed when compared with those of nontreated groups (p<0.001). A significant decrease was noted in the number of mature marrow segmented cells diabetic groups (p<0.001). Finally, G-CSF has been shown to cause neutrophilia by acting as a releasing factor for mature marrow neutrophils in diabetic rats. These results suggest that G-CSF may be used to improve nonspecific immunity in diabetic patients.