ABSTRACT
The present study was undertaken to find out the role of NO on cataractogenesis in the experimenally-induced uveitis(EIU) model. Nitrite and nitrate, stable oxidative products of nitric oxide(NO), were measured in the aqueous humor and the progression of inflammations and lens opacities were evaluated with slit lamp biomicroscope. Immunoperoxidase staining and immunofluorescent staining for inducible NO synthase(iNOS) and peroxynitrite were performed to confirm the site of production of NO and peroxynitrite. The grades of inflammation were peaked at 24 hours inflammation was gradually decreased after 48 hours and lens opacity after 72 hours. These changes returned to the baseline level by one week after LPS injection. Similarly, NO concentration in aqueous humor was peaked at 24 hours. And it was then decreased after 48 hours and returned to the baseline level by one week. These inflammatory signs and lens opacities were significantly decreased in NG-nitro-L-arginine methyl ester(L-NAME) administrated group. Inflammatory cells in anterior chamber, iris, and ciliary body expressed highly iNOS which was coincide with peroxynitrite immunolocalization. Therefore, these results suggest that cataract formation in EIU is related to the NO production in aqueous humor. Furthermore, lipid peroxidation by peroxynitrite is possibly related with cataractogenesis in EIU. But, we need a further evaluation to seek the relationship between cataractogenesis and increased nitric oxide concentration, combined with studies of other biochemical changes in anterior chamber and lens.