Fibronectin appears at the site of corneal stromal wound in rabbits

Abstract

Fibronectin (FN) is present both in plasma and in extracellular matrix, and is postulated to be involved in wound healing. The appearance of FN was investigated in the wounded rabbit cornea after corneal stroma was injured with a sharp knife or after lamellar keratoplasty was performed. An indirect immunofluorescence technique was employed to detect the presence of FN. Normal, unwounded rabbit cornea showed an intensive fluorescence at Descemet's membrane. Strong specific fluorescence was observed at the edge of a stromal wound and beneath the sliding epithelial cells after non-perforating incisions. These could be detected as early as 3 hours after injury. The fluorescence became the strongest at 6 hours, and then gradually decreased in its intensity, disappearing by about 7 days when epithelial cells entirely filled the stromal wound. In case of lamellar keratoplasty, FN was detected at the interface of the graft and the recipient cornea. These results suggest that FN plays an important role in the stromal wound hea1ing.