Assessment of wound healing in the alloxan-induced diabetic rabbit ear model

The enhancement of diabetic wound healing represents a major clinical challenge to researchers. The challenge faced is to identify a suitable animal model that best represents the human situation. However, the majority of diabetic wound healing models are in rodents and are hindered by rapid contraction and thus do not reflect epithelial cell migration, as seen in the human wound. The alloxan-induced diabetic rabbit model is a cheap, reproducible model and offers the advantage of providing a noncontractile avascular wound bed. This study aimed to compare the effects of acute hyperglycemia in the alloxan model to normal rabbit controls on wound healing, using methods of stereology. Alloxan was administered 7 days prior to surgery. Four full-thickness punch biopsy wounds were created on each ear (n = 4). Wounds were excised at 7 and 14 days and prepared for stereological analysis from Masson's trichrome-stained histological sections. It was noted that the alloxan-treated animals showed an increase in the number of inflammatory cells and fibroblasts at 14 days. In addition, it was noted that the length density of blood vessels was reduced in the alloxan-induced diabetic rabbits, representing a greater radial diffusion distance between vessels and a less efficient network for nutrient exchange. This is the first study to take a stereological approach to defining the effects of diabetes mellitus on wound healing in a noncontractile model.