[Endothelin-1 and intraocular inflammation in pigmented rabbit eyes]

We assessed the role of endothelin-1 (ET-1) in the development of anterior chamber inflammation in pigmented rabbit eyes. After the injection of ET-1 (10(-13), 10(-11), 10(-9) or 10(-7) M) into the anterior chamber, aqueous protein concentration increased significantly in a dose-dependent fashion, with a peak at 1 to 2 hours after treatment, and it returned to the normal level 8 hours after the injection. Pupillary diameter was significantly reduced when 10(-9) M or 10(-7) M ET-1 solution was injected. These effects were blocked by pretreatment with anti-prostaglandin agents, i.e., topical indomethacin or venous diclofenac sodium. In the endotoxin-induced experimental uveitis model, ET-1 concentration in the aqueous humor was significantly higher than that of normal controls as well as the plasma ET-1 level. These results suggest that ET-1 is an important mediator in the ocular inflammatory reactions through the arachidonic acid cascade.