Experimental Skin Graft In Hairless Descendants Of Mexican Hairless Dogs

Abstract

In order to enhance the successful rate of skin transplantation, tie-over method and occlusive dressings were investigated using the skin of hairless dogs. Tie-over method had no accelerative effects of the skin grafting of hairless dogs. In contrast, at 2 weeks after grafting, the graft skin has taken well under the moist environment. The hydrocolloid dressing accelerated wound healing in the donor sites. In both the graft and the donor sites, wound contraction and crust formation were not found throughout the study, although the skin of hairless dogs lagged considerably behind that of other haired dogs in wound healing. At 2 weeks after the skin grafting, histologically, the epidermis of the grafts showed thickening and irregular hyperplasia with prominent rete ridges, suggesting a relatively high rate of cell proliferation and/or differentiation. In the dermis, the formation of granulation tissues was found, and neovascularization was obscure. At 4 weeks after skin grating, the epidermis remained thick and hair follicles with well-developed sebaceous glands were observed in some portions. In the donor sites, at 2 weeks after the treatment with hydrocolloid dressing, there was reepithelialization arising from the wound margin. In the dermis, dense granulation tissues containing many fibroblasts and collagen fibers were formed. At 4 weeks after the treatment, the regenerated skin exhibited a remarkable thickening of the epidermis, especially the granular layer, and well-developed rete ridges. These findings revealed that the treatment with the hydrocolloid dressing was a valuable measure in accelerating graft take and wound healing in the donor sites of hairless dogs.