Figure 3.

Blood vessel staining in murine skin wounds. CD-31 (PECAM-1) is expressed by endothelial cells and CD-31 immunostaining is commonly used to identify blood vessels (indicated by arrows, brown staining). Representative images are shown of normal skin or the center of 3-mm excisional wounds after 5, 7, or 14 days of healing in FVB mice. This is a standard laboratory mouse strain named for its sensitivity to Friend leukemia virus B. (a) A basal number of blood vessels are present in normal skin to maintain homeostasis. (b) After 5 days of healing, an increase in CD-31 staining can be seen and new vascular structures are starting to form. (c) At 7 days, vessels with a more defined structure can be observed. (d) By 14 days post injury, the number of blood vessels has started to decline and eventually the density of blood vessels will return close to the level found in uninjured skin. Scale bar=100 μm. D, dermis; E, epidermis. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/wound