RT Journal Article A1 Shiratori, Kenji A1 Ohgami, Kazuhiro A1 Ilieva, Iliyana Bozhidarova A1 Koyama, Yoshikazu A1 Yoshida, Kazuhiko A1 Ohno, Shigeaki T1 Inhibition of Endotoxin-Induced Uveitis and Potentiation of Cyclooxygenase-2 Protein Expression by α-Melanocyte–Stimulating Hormone JF Investigative Ophthalmology & Visual Science JO IOVS YR 2004 DO 10.1167/iovs.03-0492 JF Investigative Ophthalmology & Visual Science VO 45 IS 1 SP 159 OP 164 SN 1552-5783 AB purpose. The efficacy of α-melanocyte–stimulating hormone (α-MSH) on endotoxin-induced uveitis (EIU) was investigated in rats. Several studies have demonstrated that there are various inflammatory reactions mediated by an α-MSH receptor in macrophages. In addition, as it is known that cyclooxygenase (COX)-2 is induced by a variety of stimuli and plays an important role in inflammation, COX-2 expression was also investigated in macrophage cells treated with α-MSH in vitro to clarify its anti-inflammatory effect. methods. EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). The number of infiltrating cells and protein concentration in the aqueous humor collected 24 hours after the LPS treatment was determined. The levels of prostaglandin (PG)-E2, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1 production were determined. RAW 264.7 cells were pretreated with various concentrations of α-MSH for 24 hours and subsequently incubated with 10 μg /mL LPS for 24 hours. COX-2 protein expression was analyzed by Western blot analysis. results. α-MSH suppressed the development of EIU in a dose-dependent fashion. The treatment with α-MSH reduced the PGE2, TNF-α, IL-6, and MCP-1 concentrations in aqueous humor. The COX-2 protein expression in the α-MSH group decreased. conclusions. This study suggests that α-MSH has an antiocular inflammatory effect, by suppression of PGE2, TNF-α, IL-6, and MCP-1 production and blocking of COX-2 expression. RD 12/15/2019 UL https://doi.org/10.1167/iovs.03-0492