Fibronectin is produced by blood vessels in response to injury.

Abstract

During the time of tissue repair that ensues subsequent to tissue injury, blood vessel wall fibronectin increases concomitantly with endothelial proliferation and angiogenesis. The source of this blood vessel fibronectin had not been delineated. Microvascular fibronectin is produced in situ by the proliferating vessels surrounding excisional wounds. This finding was established by extirpating 3 mm of skin from the center of a well-healed rat xenograph on the flanks of immunosuppressed mice, harvesting the injured skin sites at various stages during the healing process and staining the specimens with reciprocal species-specific antifibronectin. The proliferating donor vessels that surrounded the wounded graft had increased fluorescence staining with FITC [fluorescein-isothiocyanate dextran] conjugated mouse anti-rat fibronectin and no staining with rat anti-mouse fibronectin. Apparently, the fibronectin was produced in situ by the rat vessels and not derived from circulating mouse plasma.