An experimental model for the study of drug effects on cutaneous healing

Purpose: Immunosuppressive agents are known to interfere with the healing of surgical wounds. The increasing use of these drugs warrants a better understanding of their effects on wound healing. The aim of this study was to develop an experimental model that would allow for a reliable and rapid assessment of drug effects on cutaneous wound healing. Methods: Thirty syngeneic Lewis rats underwent surgical incision on their dorsal region, in the presence or absence of a three-week regimen of immunosuppressant drug therapy (i.e., cyclosporin, azathioprine, and prednisone). Surgical site tissue was collected at intervals over 21 days after surgery and analyzed for cell number and collagen fiber content. Both of these quantitative assessments were performed using digital image capture with the Image Pro Plus 4.5 software. Results: Computerized histomorphometric analyses revealed an apparent inhibition of cellular responses and collagen fiber production in drug-treated animals compared to control animals. Conclusion: The experimental model was reproducible, easy to perform, and allowed for quantitative histological evaluations. It may be useful for the study of surgical healing in the presence of other drug classes.