The dynamics of endothelial changes in vivo following standardized skin injury.

Abstract

Vascular changes, that is, functional and cellular endothelial changes, are of essential importance in healing. Alongside these vascular changes, inflammatory factors and hypoxia may play an important role in recovery. To investigate the dynamics of functional and cellular endothelial changes and hypoxia in vivo following standardized skin damage caused by tape stripping. Vascular changes (endothelial cell proliferation, vascular network size, vessel diameter) and hypoxia-inducible factor-1α were examined immunohistochemically using a CD31/Ki67 double staining and HIF-1α single staining. Cutaneous perfusion was evaluated using the Twente Optical Perfusion Camera (TOPCam). The initial phase is seen to be dominated by endothelial cell proliferation, HIF-1α expression, and vasodilatation. Cutaneous perfusion intensity is particularly increased in the first 16hours. The late phase of recovery (after 72hours) is characterized by a peak of expansion of the vascular network and a second peak of endothelial cell proliferation and HIF-1α expression. Endothelial cell proliferation and HIF-1α expression appear to be (strongly) related, having maximum levels at 16hours and 72hours. Angiogenesis and HIF-1α expression are not continuous processes, but rather occur intermittently.