Previous studies from this and other laboratories suggest that an intraocular generation of certain reactive oxygen species (ROS) constitutes a major risk factor in the pathogenesis of cataracts. The PI has also demonstrated that the ROS can be effectively scavenged by pyruvate preventing cataracts in selenite and galactose models. In addition, he has recently observed that it inhibits lens protein glycation and polyol synthesis as well. Hence, he hypothesizes that such ketoacids and their esters can perform a useful role in cataract prevention. It is commonly known that the bio-effectiveness of the esters is greater than that of the parent compound because of their enhance translocation into the cell. Therefore, further studies will be conducted with the following specific aims. 1. Study the antioxidant effect of ethyl pyruvate in vitro by assessing its ability to prevent against oxidative damage to the lens active transport, loss GSH, ATP, and of soluble proteins due to their oxidative in solubilization. The hydrolysis of the ester will also be studied. 2. Extend these studies with alpha- ketoglutarate and its ester in view of its slower metabolism and consequently a more sustained bio- availability. 3. Study the in vivo effectiveness of the esters against oxidative stress and cataract formation induced by sodium selenite and galactose. 4. Determination of the anti-glycating effect of the keto compounds using purified bovine lens crystallins. The preventive process supposedly involves their ROS scavenging properties and/or competitive inhibition of the Schiff base formation between the keto group of the sugars and the lens protein -NH2. 5. Study the prevention of such glycation by these compounds in vivo in diabetic and galactosemic animals.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001292-22
Application #
2608550
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1978-09-01
Project End
1999-11-30
Budget Start
1997-12-01
Budget End
1998-11-30
Support Year
22
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Maryland Baltimore
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
003255213
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Kronschläger, Martin; Löfgren, Stefan; Yu, Zhaohua et al. (2013) Caffeine eye drops protect against UV-B cataract. Exp Eye Res 113:26-31
Varma, Shambhu D; Kovtun, Svitlana; Hegde, Kavita R (2011) Role of ultraviolet irradiation and oxidative stress in cataract formation-medical prevention by nutritional antioxidants and metabolic agonists. Eye Contact Lens 37:233-45
Varma, Shambhu D; Hegde, Kavita R (2010) Kynurenine-induced photo oxidative damage to lens in vitro: protective effect of caffeine. Mol Cell Biochem 340:49-54
Varma, Shambhu D; Hegde, Kavita R (2010) Prevention of oxidative damage to lens by caffeine. J Ocul Pharmacol Ther 26:73-7
Hegde, K R; Varma, S D (2009) Electron impact mass spectroscopic studies on mouse retinal fatty acids: effect of diabetes. Ophthalmic Res 42:9-14
Hegde, Kavita R; Kovtun, Svitlana; Varma, Shambhu D (2007) Induction of ultraviolet cataracts in vitro: prevention by pyruvate. J Ocul Pharmacol Ther 23:492-502
Varma, S D; Hegde, K R; Kovtun, S (2006) Oxidative damage to lens in culture: reversibility by pyruvate and ethyl pyruvate. Ophthalmologica 220:52-7
Hegde, K R; Varma, S D (2005) Combination of glycemic and oxidative stress in lens: implications in augmentation of cataract formation in diabetes. Free Radic Res 39:513-7
Hegde, K R; Varma, S D (2005) Prevention of cataract by pyruvate in experimentally diabetic mice. Mol Cell Biochem 269:115-20
Hegde, K R; Varma, S D (2005) Cataracts in experimentally diabetic mouse: morphological and apoptotic changes. Diabetes Obes Metab 7:200-4

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