Stimulation of macrophage function by interphotoreceptor retinoid-binding protein: production of nitric oxide.

Bae,  Sun Ryang

doi:1999.13.2.57

Korean J Ophthalmol > Volume 13(2); 1999 > Article

Research Support, Non-U.S. Gov't

Korean Journal of Ophthalmology 1999;13(2):57-64.
DOI: https://doi.org/10.3341/kjo.1999.13.2.57 Published online December 30, 1999.

Stimulation of macrophage function by interphotoreceptor retinoid-binding protein: production of nitric oxide.

Sun Ryang Bae

Department of Ophthalmology, Taejon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Korea.

Abstract

In this study, we investigated whether retinal soluble proteins, such as interphotoreceptor retinoid-binding protein(IRBP), play a role in the induction of nitric oxide by macrophages in vitro. Cells from the murine macrophage cell line RAW 264.7 and rat and rabbit peritoneal macrophages were incubated in the presence of retinal soluble protein. The nitrite level in the cultured supernatant was evaluated for nitric oxide production using the Griess reaction. IRBP induced significant, dose-dependent nitrite production in both RAW 264.7 and rat peritoneal macrophages. Induction of inducible nitric oxide synthase (iNOS) by retinal proteins was inhibited by the iNOS-specific inhibitor, aminoguanidine, and the tyrosine inhibitor, genistein. These results show that soluble retinal proteins significantly induce nitric acid production by macrophages. Increased production of reactive oxygen species by macrophages in the presence of this soluble retinal protein in vivo may accelerate photoreceptor degeneration in uveitis.