Résumé
The possible contribution of free-radicals in progression of retinitis pigmentosa [RP] was investigated by appraising the free radical scavenging enzymes superoxide dismutase [SOD] and catalase in 76 patients suffering from this disease compared to 20 healthy subjects as control. Blood haemoglobin and certain serum parameters viz., ceruloplasmin, total protein, albumin, globulin, vitamin E, copper and zinc were also estimated. This is to clarify their conceivable involvement in pathogenesis of RP. These parameters were additionally analyzed in blood, serum and retinal samples of control and UV-irradiated rabbits for comparison. Significant increased activity of erythrocyte SOD and catalase in RP patients with concomitant decrease of serum vitamin E and copper revealed an active role of these factors in the scavenging of free radicals that most probably associate RP. However, in RP patients haemoglobin and the other serum parameters remained relatively unchanged. The performance of erythrocyte scavenging enzymes and serum vitamin E antioxidant activity were significantly lowered in head-UV-irradiated rabbits. Meanwhile, retinal SOD and catalase activities were also reduced after deliberate exposure to UV. A strong relationship between the development of RP, environmental exposure to UV and the protective efficacy of SOD, catalase and vitamin E was suggested