An immunohistochemical study of endothelin-1 converting enzyme in the human eye.
OBJECTIVE
The important role of ET-1 in vasoconstriction has been shown for the vasoregulation in the retina, choroid and optic nerve. ET-1 induced vaso-constriction, however, can be treated effectively at the level of endothelin-1 converting enzyme (ECE-1) by ECE-1 inhibitors because ECE-1 converts biologically almost inactive big endothelin to endothelin-1 (ET-1), the most potent vasoconstrictor known. The purpose of this study was to clarify the anatomical distribution of ECE-1 in the human eye.


METHODS
11 post-mortem eyes were fixed in 4% formalin and embedded in paraffin. 4 microm thin sections were analyzed immuno-histochemically using a self-produced monoclonal primary antibody against human ECE-1 and a polyclonal alpha-actin antibody for comparison.


RESULTS
ECE-1 -IR was demonstrated in the corneal epithelium, vascular smooth muscle and endothelial cells, and in the non-vascular smooth muscle cells of the ciliary body, the dilator and sphincter muscle of the iris.


CONCLUSIONS
A strong immunoreactivity for ECE-1 can be found in the blood vessels of the retina, optic nerve and choroid. Therefore, it should be possible to treat ET-1-induced vaso-constriction in the eye using ECE-1 inhibitors, especially in diseases like hypertensive vasculopathy, vasospasm, vaso-occlusions or low tension glaucoma.
University Eye Clinic Dresden, Dresden, Germany. gwollens@hotmail.com
Gregor
G
Wollensak
Bernd
B
Löffler
Beate
B
Beyermann
Christian
C
Ihling
D000328:Adult; D000911:Antibodies, Monoclonal; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D002924:Ciliary Body / Q000201:enzymology; D000072396:Endothelin-Converting Enzymes; D019573:Epithelium, Corneal / Q000201:enzymology; D005123:Eye / Q000201:enzymology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007498:Iris / Q000201:enzymology; D008666:Metalloendopeptidases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D012171:Retinal Vessels / Q000201:enzymology; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; C000606923:ECE1 protein, human; D000072396:Endothelin-Converting Enzymes