An immunohistochemical study of endothelin-1 in the human eye

Purpose. Endothelin-1 (ET-1) is a potent vasoconstrictive and neural peptide that has been demonstrated to be present and functionally active and important in the eye. This study was undertaken to examine for the first time the cellular distribution of ET-1 in the whole human eye. Methods. Twelve human eyes were examined by immunohistochemical staining of paraffin sections, using an anti-ET-1 primary antibody and an ABC-detection system. Results. Endothelin-1-immunoreactivity (ET-1-IR) was detected primarily in the fibrovascular stroma of the iris, ciliary body and choroid, in the retinal blood vessels, the ciliary and optic nerves, and in the corneal and the non-pigmented ciliary epithelium. Conclusion. In the eye, ET-1-IR is present in fibrovascular, neural and epithelial structures. Changes in the distribution and concentration of ET-1 may be relevant to a variety of ocular diseases including diabetes mellitus, hypertension, sickle cell disease, optic neuritis, AION, papilledema, corneal ulcer, corneal epithelial dystrophy or after keratoplasty.