EFFECTS OF DIFFERENT ANTIOXIDANTS ON LENS-INDUCED UVEITIS

For evaluation of the effects of different free-radical scavengers on biochemical changes in lens-induced uveitis (LIU), ten male Wistar rat s were sensitized for 8 weeks using bovine lens protein and Freund's a djuvant. The uveitis was induced by disruption of the lens capsule. On e group of animals received superoxide dismutase and catalase (SOD/CAT ); a second group of animals was treated with vitamin E. Lipid peroxid es (LPO) of the retinal tissue and aqueous humor served as parameter o f oxidative tissue damage. Glutathione (GSH/GSSG) of the aqueous humor was evaluated as a parameter of the tissue's redox state. For evaluat ion of the inflammatory response, myeloperoxidase activity (MPO) was d etermined in the iris/ciliary-body complex. SOD/CAT produced no improv ement in the significantly (P<0.05) elevated MPO and LPO values record ed for untreated control animals. Following vitamin E treatment the GS H/GSSG and LPO values in aqueous humor were markedly improved as compa red with controls. Retinal LPO values were significantly (P<0.05) redu ced as compared with controls. No change in MPO levels was observed. T he results demonstrate that enzymes such as SOD and CAT do not influen ce tissue damage at a significant level, whereas radical chain breaker s such as vitamin E can do so. However, the inflammatory response itse lf is not reduced. To achieve global results, drugs are necessary that act on both free radicals produced by noninflammatory pathways and th ose originating from inflammation.