Onset and Localization of Collagen Synthesis during Wound Healing in Open Rat Skin Wounds 1

Summary

Previous studies suggest that there is an initial “lag” or “latent” phase following wounding. During this 4- to 6-day period, there is very little collagen synthesis as judged by tensile strength measurements, light and electron microscopy, and changes in the specific activity of hydroxyproline. In the present study a sensitive biochemical method was used to measure collagen synthesis during the initial phase of open wound repair in rat skin and a significant increase in collagen synthesis was detected as early as 24 hr. Analysis of various wound components demonstrated that the early increased collagen synthesis was localized in the panniculus carnosis. Collagen synthesis continued to increase with the greatest activity occuring on day 7 and by day 11 had returned to normal skin levels. We conclude from these studies that collagen synthesis begins by 24 hr after wounding and that the initial phase of wound repair is not preceded by a “lag phase”.