IMMUNOLOCALIZATION OF BASIC FIBROBLAST GROWTH-FACTOR DURING WOUND REPAIR IN RAT RETINA AFTER LASER PHOTOCOAGULATION

Background: Basic fibroblast growth factor (bFGF) stimulates the mitog enesis of various cells and plays a key role in wound repair. We studi ed the immunohistochemical localization of bFGF during wound repair in the rat retina after laser photocoagulation. Methods: Krypton laser p hotocoagulation was performed on the eyes of pigmented rats. The eyes were enucleated on days 1, 3, 7, 14 and 28 after the photocoagulation, and the immunohistochemical localization of bFGF was assessed. Two di fferent monoclonal antibodies and one polyclonal antibody against bFGF as first antibodies were used. Results: Marked immunoreactivity for b FGF was found in the ganglion cell layer, and weak immunoreactivity fo r bFGF was found in the retinal pigment epithelial (RPE) cells of the normal adult rat retina. On day 3 after laser photocoagulation, the nu clei and cytoplasm of proliferating RPE cells at the center of the pho tocoagulated lesion showed intense bFGF immunoreactivity. The nuclei o f RPE cells around the lesion showed intense bFGF immunoreactivity. Ma crophages that migrated into the lesion showed positive staining for b FGF. These immunoreactivity decreased with time. Controls (0.05 M Tris -HCl buffer, normal serum, or these same antibodies preabsorbed with b FGF) did not show positive staining. Conclusion: The finding of an ele vated expression of bFGF immunoreactivity in the photocoagulated lesio n suggests that bFGF may play a role in wound repair in the rat retina after laser photocoagulation.