Fibronectin synthesis by the rabbit cornea: effects of mouse epidermal growth factor and cyclic AMP analogs

We investigated whether the cornea can synthesize fibronectin which participates in corneal wound-healing. We also examined the effects of epidermal growth factor (EGF) and cyclic AMP analogs on fibronectin synthesis by the cornea. Rabbit corneal blocks were cultured in medium without serum, and the amount of fibronectin in culture medium was determined by ELISA assay. When rabbit corneal blocks were cultured in the medium alone, fibronectin contents in the medium increased with increase in the incubation period. This increase was enhanced by the addition of EGF to the culture medium, and was inhibited by addition of a protein synthesis inhibitor, cycloheximide. The addition of cAMP analogs, 8-bromo cyclic-AMP and dibutyryl cAMP, to the culture medium also increased the rate of fibronectin production by the cornea. These results show that the cornea can synthesize fibronectin and its synthesis is stimulated by EGF and cAMP analogs.