The influence of experimental diabetes and insulin treatments on the biochemical properties of rat skin incisional wounds.

The mechanical properties (tensile strength, extensibility, relative failure energy) of skin incisional wounds were analyzed after 7, 10 and 20 days of healing in normal rats, diabetic rats treated with insulin from the day of wound infliction and diabetic rats treated with insulin from the 5th preoperative day. Untreated diabetes resulted in a reduction of the failure energy of skin wounds during the 20 days of wound healing. After 7 days of wound healing, insulin treatment starting on the day of wound infliction or on the 5th preoperative day did not eliminate this reduction in failure energy of wounds induced by diabetes. However, a positive correlation was found between the duration of the insulin treatment and the failure energy of the wounds. After 10 and 20 days of wound healing, the mechanical parameters of wounds from diabetic rats treated with insulin from the day of wound infliction or from the 5th preoperative day did not differ from those of the control wounds. The experiment demonstrates that insulin treatment is essential for adequate wound healing in diabetes. Insulin treatment from the day of wound infliction or from the 5th preoperative day is not, however, sufficient to prevent the inhibitory effects of diabetes in the early phase of wound healing.