Evaluation of the relationship between serum levels of insulin, cortisol and growth hormones and wound healing in normal and diabetic rats

Introduction: Several factors such as diseases, medications and humoral agents can delay or speed up wound healing process. Because of the limited information about the hormonal changes during wound healing, in this study the relationship between serum levels of growth hormone, insulin and cortisol and wound healing in normal and diabetic rats was evaluated. Methods: Male Wistar rats )weighing 250 ± 20 g( were divided into three groups: control, normal (non-diabetic) and diabetic (induced by streptozotocin). The wound size made on the back of normal and diabetic rats was measured at days 0, 7, 14 and 21, and the serum levels of growth hormone, insulin and cortisol were measured. Results: The speed of wound healing in normal rats was higher than diabetic rats. Serum insulin concentrations were less in the diabetic rats in comparison with the normal and control groups (p<0.001, and showed correlation with wound healing process in diabetic rats (p<0.01). Serum cortisol concentrations decreased in normal and diabetic groups during wound healing (p<0.001) but did not show significant correlation with this process. Serum growth hormone levels did not significantly change in any of the groups, and did not show significant correlation with wound healing process, too. Conclusion: Reduction of serum insulin level is probably responsible for delayed wound healing in diabetes, and intrinsic mechanisms facilitate wound healing in normal and diabetic conditions by reducing the release of cortisol.