Effects of granulocyte-macrophage colony-stimulating factor on incisional wound healing in an experimental diabetic rat model

The exact nature of poor wound healing in diabetes is uncertain. Neutrophil s play a critical role in the host defense mechanism, and it is suggested t hat impaired neutrophil functions cause healing difficulties with or withou t infections in diabetic patients. Granulocyte-macrophage colony-stimulatin g factor (GM-CSF) is used clinically when given systematically to increase the circulating neutrophils, but its wound-healing effects have not been sy stematically studied. This study was undertaken to examine the effects of G M-CSF on incisional wound healing in an experimental diabetic rat model. Fo rty rats were randomly divided into three groups, group I receiving saline as control, diabetes-induced group II receiving saline and diabetes-induced group III receiving GM-CSF. The anesthetized rats in all groups were wound ed 21 days after diabetes induction by streptozotocin. Blood neutrophil cou nts and neutrophil fractions were also determined three days after wounding . Tensile strengths of wounded skin and the hydroxyproline (hyp) level of t he wound were determined and wound healing processes were evaluated by ligh t and electron microscopy, fourteen days after wounding. Neutrophil counts and phagocytosis were significantly increased in group III and neutrophil c ounts decreased in group II (p < 0.05). Although the hydroxyproline level o f wound tissue significantly decreased in group II as compared with group I II (p < 0.05), there was no differences of tensile strength between group I I and III (p < 0.05). Wound score in group II was less than that in groups I and III (p < 0.05). It is concluded that PMN may have a role in modulatin g wound healing. GM-CSF may be useful for creating better wound healing hea ling. GM-CSF may be useful for creating better wound healing in risky patie nts such as diabetics.