title: Ultraviolet-A induced delayed wound contraction and decreased collagen content in healing wounds and implant capsules.
abstract: 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.
authors.affiliation: Division of Plastic Surgery, Baylor College of Medicine, Houston, Tex.
authors.forename: G
authors.initials: G
authors.lastname: Ozcan
authors.forename: S
authors.initials: S
authors.lastname: Shenaq
authors.forename: H
authors.initials: H
authors.lastname: Chahadeh
authors.forename: M
authors.initials: M
authors.lastname: Spira
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism*; D006909:Hydroxyproline / Q000378:metabolism; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D012828:Silicones; D014466:Ultraviolet Rays; D014945:Wound Healing / Q000502:physiology / Q000528:radiation effects*
chemical_list: D012828:Silicones; D003094:Collagen; D006909:Hydroxyproline