Effects of Endothelin-1 on Choroidal Vessels: 2. Study Using Indocyanine Green Videoangiography

PURPOSE: The effects of intravenous administration of endothelin-1(ET-1) on choroidal arteries were studied using indocyanine green videoangiography. METHODS: The changes in caliber of the choroidal arteries in eight albino rabbits were examined using indocyanine green videoangiography with a scanning laser ophthalmoscope and an image analysis system. RESULTS: Administration of 10(-9) mol/kg of ET-1 induced a significant reduction in diameter of 50.5-80.1%(median = 64.15%) 5 minutes after administration. The constriction continued for more than 60 minutes. CONCLUSION: This study demonstrates that intravenous administration of ET-1 induces long-lasting constriction of choroidal arteries. This suggests that ET-1 may participate in the regulation of choroidal artery tone.