Endothelin 1 is a growth factor for corneal endothelium

Endothelin 1 (ET1) is a newly discovered peptide found in various tissues, which exerts its biological effects through autocrine or paracrine pathways. Its presence and binding sites in the anterior chamber of the eye have recently been reported. Using a binding assay, we found the presence of a single class of receptors for ET1 on bovine corneal endothelial cells, whereas no ET1 could be detected in their conditioned medium. ET1 receptors appeared to be involved in BCE cell proliferation and migration. Furthermore, ET1 effects were additive to that of basic Fibroblast Growth Factor. Thus, we have shown for the first time that ET1 acts as a growth factor on corneal endothelium through a paracrine mediated action. This research suggests that ET1 has a role in corneal endothelium physiology and might provide a new field of investigation in the pharmacology of corneal endothelial healing.