Ozcan G, Shenaq S, Chahadeh H, Spira M
Division of Plastic Surgery, Baylor College of Medicine, Houston, Tex.
Plast Reconstr Surg. 1993 Sep;92(3):480-4. doi: 10.1097/00006534-199309000-00016.
Chronic exposure to ultraviolet-A radiation causes changes in the biochemistry of dermal connective tissue. To investigate its effects on wound healing, we irradiated Sprague-Dawley rats for 4 months using a black ray ultraviolet-A radiation source (560 J/cm2). Full thickness skin wounds of 2 cm in diameter were then created on the back of each animal and silicone cubes were implanted subcutaneously into the irradiated area of the back. Wound contraction in the irradiated animals (n = 28) was significantly slower than that of the controls (n = 29) (p < 0.001). Postoperatively, the hydroxyproline content of the contracted wounds and the implant capsules was assessed at 6 and 12 weeks, respectively. In the irradiated animals, it was found to be significantly less than that of the controls (p < 0.001). A delay in wound contraction and a decrease in hydroxyproline content of healing wounds and implant capsules, reflecting an alteration in collagen metabolism, are two effects of prolonged intermittent ultraviolet-A radiation pretreatment.
