Abstract
Purpose: :
Prostaglandin E2 (PG), arachidonic acid (AA) and endothelin (ET–1) are proposed to cause apoptosis of retinal pigmented epithelium (RPE) under ischemia conditions. We determine the direct efffects of PGE2, AA and ET–1 on bovine RPE cells under normoxic condition.
Methods: :
Bovine RPE cells were incubated with PGE2 (1–1000ng/ml), AA (1–50 µM) and ET–1 (1–1000ng/ml) under normoxic condition (21%O2 and 5% CO2 at 37ºC) for 72 hours. Viability was determinated using the Cell Proliferation Kit (XTT) method.
Results: :
Higher concentrations of PGE2 (0.1–1 µg/ml), AA (20–50µM) and ET–1 (0.1–1µg/ml) induced apoptosis of RPE in dose dependent manner. While low concentrations of these compounds had no effect. When RPE cells were incubated with COX–2 inhibitor (NS 398, 1µM), COX–1 and 2 inhibitor (diclofenac, 1µM) for 72h also had no effect.
Conclusions: :
We observed apoptosis only at high concentrations of PGE2, AA and ET–1, indicating that apoptosis may be induced by COX–2 and ET–1 under ischemic conditions.
Keywords: eicosanoids • retinal pigment epithelium • apoptosis/cell death