EP2 receptor and ocular inflammatory responses in the mice.

Abstract

Abstract: : Purpose: To evaluate the role of prostaglandin E₂ receptor subtype EP₂ in ocular inflammation induced by different inflammatory agents Methods: . Wild Type (+/+) and knock Out (–/–) mouse eyes were topically treated with PGE₂, RANTES, SDF–1 and PAF. For fluorescein angiography, 0.1 ml of 5% Sodium fluorescein was injected intra–peritoneally, fifteen minutes after administration of the inflammatory agent. The eyes were then photographed with a slit–lamp camera (Topcon) under a blue light After 30–40 minutes of treatment, mice were euthanized with carbon–dioxide and the aqueous humor was collected by paracentesis of anterior chamber. LPS was administered by intravitreal injections and aqueous humor was collected after 24 hours of treatment. Protein from the aqueous humor was measured in a spectrophotometer using Lowry’s method.A separate group of (+/+) and (–/–) mice were treated with EP₄ antagonist to determine the involvement of EP₄ receptor in the ocular inflammation. Results:There was a significant reduction in the protein values in the aqueous humor of the knockout mice treated with PGE2 and LPS as compared to the wild type animals. The protein value in PGE2 (+/+) was 7.7 mg/ml and that of (–/–) was 3.6 mg/ml. Protein value of LPS (+/+) was 23.5 mg/ml and (–/–) was12.57 mg/ml.The aqueous humor protein values of the (–/–) mice treated with RANTES, SDF–1 and PAF also were reduced as compared with the (+/+) but not to the same extent as LPS and PGE₂. Conclusions:From the results it is evident that the LPS, and PGE₂ induced ocular responses are mediated by EP₂ receptor. The effects of RANTES are partly mediated by EP₂ receptor, but that of PAF and SDF–1 are not mediated by EP₂ receptor.

Keywords: pharmacology • pharmacology • pharmacology