Slovenská chirurgia 4/2012

Excision model of wound healing in rat – histomorphological examination

The aim of the study was to elaborate the excision model of healing of the skin wounds in rats on a histological level in chosen intervals from the creating of the wounds. The study was designed to describe particular mechanisms during secondary healing in all phases of healing. Material and methods: Animals (Sprague Dawley rats, males, N=24) were divided into three groups according to interval of sampling of operating wound for histological evaluation. Four excision wounds of 4 mm diameter were made on the dorsum of rats. Wounds were sampled on the 2nd, 6th and 14th day of operating procedure. The samples were stained with hematoxylin and eosine and van Gieson. Semiquantitative method was used for evaluation of samples. Results: We observed proliferative phase of epidermal borders after 48 hours. PMNL were formed into the demarkation braid. Completly upperbridge of the wound with new epitel cells was seen after 144 hours. Macrophages dominated in inflamatory infiltrate. Granulation tissue consisted of fibroblasts, endothelial celles and extracellular matrix was found in the bed of wounds. Mostly of collagen was amorphous organized. New epidermis had 3 – 5 layers after 336 hours. Fibred collagen overweighted amourphous collagen. In conclusion, rat skin wounds can serve as a model for studying influence of different factors for enhancing of wound healing.

Keywords: secondary healing of the wounds, histological examination, model, rat.