The Role of free radical reactions and antioxidants in diabet induced rat lens

Ill ABSTRACT Master Thesis THE ROLE OF FREE RADICAL REACTIONS AND ANTIOXIDANTS IN DIABET INDUCED RAT LENS Mehmet TUZCU Fırat University Graduate School of Natural and Applied Sciences Department of Biology 2000, Page:64 Cataract is the clouding of the lens of the eye, which reduces the amount of incoming light and results in the deterioration of vision. The increases in malondialdehyde (MDA) level in the cataractous lenses is the cataract formation. MDA reacts in vivo and in vitro with free amino groups of proteins, phospholipids, or nucleic acids. As a result of this, advanced glycation end products (AGE) of proteins occur in lens. In this study, the possible role of antioxidant drugs aspirin and aminoguanidine was investigated in STZ induced diabetic rat lens. For this, the MDA content was measured and disulphide bond formation of proteins investigated in the diabet induced rat lens. It was found that the increased glycation (non-enzymatic glycosylation) of lens proteins caused by diabetes was less in the diabetic rats treated with aspirin and aminoguanidine. In diabetic lens samples, water soluble proteins were decreased whereas, water-insoluble proteins increased when compared to other groups. In addition, MDA level was found to be lower in diabetes supplemented with aspirin and aminoguanidine than diabetic group. These results indicated that, antioxidant drugs aspirin and aminoguanidine have possible protective effect against cataract development in diabetic rats. Key Words: Diabet, Free radicals, Cataract, Lens proteins, Antioxidant, SDS-PAGE, Malondialdehyde. *,:,?'. i. '?;>,