Further Studies on the Effect of Prostanoid EP4 Receptor Stimulation on Aqueous Humor Dynamics in Monkeys

Abstract

Abstract: : Purpose: The EP₄ receptor is unique among ocular prostanoid receptors in that its effect on intraocular pressure (IOP) do not involve increased uveoscleral outflow. Previous outflow studies revealed an effect on pressure–dependent outflow rather than uveoscleral outflow. These studies have now been extended by examining the effect of the selective EP₄ receptor agonist 3,7–dithia PGE₁ isopropyl ester on aqueous humor flow. Methods: Aqueous humor flow was measured with a scanning ocular fluorophotometer in both eyes of female cynomolgus monkeys rendered unilaterally ocular hypertensive by circumferential laser treatment. Results: A single dose 3,7–dithia PGE₁–isopropyl ester 0.01% did not influence aqueous humor flow in either normotensive or hypertensive eyes. Values ± SEM obtained are as follows: Vehicle treatment hypertensive eyes 1.98 ± 0.53, normotensive eyes 2.50 ± 0.44 = 3,7–dithia PGE₁–isopropyl ester 0.01% treatment hypertensive eyes 1.85 ± 0.21, normotensive eyes 2.39 ± 0.26. These effects were statistically insignificant. Conclusions: Prostanoid EP₄ receptor stimulation does not exert a meaningful influence on aqueous humor flow in primates .. .

Keywords: eicosanoids • inflow/ciliary body • aqueous