Effect of some antioxidants on retinal ischemia-reperfusion formed in guinea pigs

Ill ABSTRACT Master Thesis EFFECT OF SOME ANTIOXIDANTS ON RETINAL ISCHEMIA-REPERFUSION FORMED IN GUINEA PIGS İhsan EKİN Fırat University Graduate School of Natural and Applied Sciences Department of Biology 2002, Page: 42 This study shows the possible role of various forms of vitamin E on free oxygen radicals which formed during ischemia-reperfusion (I-R) in guinea pig retina. The animals were randomly divided into the five groups. These were named as group 1 (control), group 2 (I-R), group 3 (1-R+alpha tocopherol), group 4 (l-R+gamma tocopherol) and group 5 (I-R+vitamin E+TPGS). In the experiment, the right eyes of quinea pigs were used for ischemia-reperfusion. Group 3, 4 and 5 received three subcutaneous injections with alpha tocopherol, gamma tocopherol and vitamin E -TPGS during the reperfusion period of 24 hours. The animals were sacrificed after 24 hours of reperfusion. Then, retinas were isolated and processed for the quantification of malondialdehyde (MDA) and glutathione (GSH) levels. At the end of this experiment, all the three substances (alpha tocopherol, gamma tocopherol, vitamin E-TPGS) showed statistically significant protection aganist the formation of MDA when compared to I-R group. In addition, quantity of glutathione in samples was determined and according to the results, GSH level in group 4 was found close to the group 2 and GSH levels in group 3 and 5 were found higher than group 1 and 2. As a result, vitamin E forms; alpha tocopherol, gamma tocopherol and vitamin E-TPGS prevent formation of peroxidation substrat MDA and protect quantity of antioxidant GSH. Key Words: Ischemia-Reperfusion, Free Oxygen Radicals, Antioxidant, Glutathione, Malondialdehyde, Guinea Pig, Vitamin E, Retina