Abstract
Abstract: :
Purpose: To evaluate the effect of P2Y2 receptor agonist (INS542) on the outward permeability of retinal pigment epithelium (RPE) using differential vitreous fluorophotometry (DVF). Methods: One eye from each of 30 Dutch rabbits was assigned to one of three groups. Eyes in group 1 (n=11) received a vitreous injection of 0.1 mL of 1 mM INS542; eyes in group 2 (n=9) received a vitreous injection of 0.1 mL of 1 mM INS316 (UTP), which is structurally similar to INS542 but is presumably degraded by the time it diffuses across the retina and reaches the RPE; eyes in group 3 (n=10) received a vitreous injection of PBS alone. DVF was performed 180 minutes after the intravitreal injection. Then, the fluorescein (F) / fluorescein monoglucuronide (FG) ratio was calculated. If the outward permeability increases, the ratio decreases. Results: The averages (standard deviation) of the F/FG ratio were 0.18 (0.12), 0.40 (0.25), and 0.48 (0.27) in group 1, 2, and 3, respectively. The F/FG ratio in group 1 was significantly lower than those in group 2 and 3, respectively (p<0.05 and p<0.01). Conclusion: P2Y2 receptor on RPE plays an important role in the outward permeability. P2Y2 receptor agonist, INS542, may accelerate the outward active transport function of RPE.
Keywords: 567 retinal pigment epithelium • 541 receptors: pharmacology/physiology