Insulin-like growth factor-1 reverses diabetes-induced wound healing impairment in rats

Impaired wound healing is an enigmatic and debilitating complication of diabetes. A consensus as to the pathogenesis of this disorder has yet to emerge. Recent concepts suggest that IGF-1 is an important regulator of the healing process. The level of this growth factor is reduced in the wound environment of diabetics. We tested the premise that IGF-1 administration may prevent or ameliorate wound healing impairment in streptozotocin (STZ, 55 mg/kg, iv) diabetic rats. IGF-1 (15 micrograms/day) or placebo was infused via mini-osmotic pumps into standardized stainless steel dorsal wound chambers. Wound-related parameters including protein, DNA, hydroxyproline and macrophages were decreased as a function of diabetes. A 14-day treatment with IGF-1 reversed the diabetes effect and increased total hydroxyproline, DNA, protein and macrophage numbers by 48%, 52%, 31% and 40% above vehicle-control values, respectively. The data support the premise that diabetes, related suppression of IGF-1 and/or macrophage function within the wound environment is responsible, at least in part, for the wound healing impairment in this disease state.