The hypothesis proposed to test is that reactive species of O2 are the initiators of oxidative stress-induced damage to the lenticular plasma membrane lipids and proteins in cataract. The objective is to investigate the crucial areas of the mechanism of cataract involving oxidation of proteins and peroxidation of phospholipids of plasma membranes. Exposing the lens plasma membranes to various oxidative stresses in vitro, modification of the intrinsic membrane protein MP26, will be determined using SDS polyacrylamide gel electrophoresis. After identical treatment, membrane phospholipids will be assessed by measuring the formation of aminophospholipid.malondialdehyde adduct using TLC, HPLC and spectrofluorometry. Fatty acids will be analysed by gas chromatography and HPLC. Malondialdehyde(MDA) and lipid hydroperoxides will be estimated in lens to observe their possible correlation with the loss of unsaturated fatty acids in cataracts. Polarographic and ESR spectroscopic techniques will be used to detect O2.-, OH., H2O2 and adriamycin semiquinone free radical in aqueous humor, and in lens of rabbit by addition of calf lens microsomal NADPH oxidase system in vitro. Attempts will be made to identify Schiff base conjugate formed by polymerization of aminophospholipids of lens under oxidative stress and in cataracts in the human and animal using (14C-)MDA or phosphatidyl ethanolamine. Oxidative stress-induced cross linking of membrane-SH in vitro, and in precataract and early cataract induced in rabbits by galactose will be determined by using (14C-)iodoacetamide. To assess the role of enzymic defenses in cataracts, analysis of the bioactive and inactive forms of superoxide dismutase, catalase and GSH peroxidase will be done using spectrophotometric technique and radioimmunoassay. Tests of antioxidants in the therapy of experimental cataracts will be continued. Arrest of the progression of cataract in the human at an early stage will be of immense help to the patients. The economic benefit resulting from reduction of the number of surgical procedures for cataracts also must not be underestimated.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003012-13
Application #
3257331
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1978-09-01
Project End
1993-02-28
Budget Start
1990-09-01
Budget End
1993-02-28
Support Year
13
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Type
Schools of Medicine
DUNS #
City
New York
State
NY
Country
United States
Zip Code
10029
Bhuyan, D K; Reddy, P G; Bhuyan, K C (2000) Growth factor receptor gene and protein expressions in the human lens. Mech Ageing Dev 113:205-18
Reddy, P G; Bhuyan, D K; Bhuyan, K C (1999) Lens-specific regulation of the thioredoxin-1 gene, but not thioredoxin-2, upon in vivo photochemical oxidative stress in the Emory mouse. Biochem Biophys Res Commun 265:345-9
Bhuyan, D K; Huang, X; Kuriakose, G et al. (1997) Menadione-induced oxidative stress accelerates onset of Emory mouse cataract in vivo. Curr Eye Res 16:519-26
Bhuyan, D K; Master, R W; Bhuyan, K C (1996) Crosslinking of aminophospholipids in cellular membranes of lens by oxidative stress in vitro. Biochim Biophys Acta 1285:21-8
Bhuyan, D K; Bhuyan, K C (1994) Assessment of oxidative stress to eye in animal model for cataract. Methods Enzymol 233:630-9
Longas, M O; Bhuyan, D K; Bhuyan, K C et al. (1993) Dietary vitamin E reverses the effects of ultraviolet light irradiation on rat skin glycosaminoglycans. Biochim Biophys Acta 1156:239-44
Bhuyan, K C; Bhuyan, D K; Santos, O et al. (1992) Antioxidant and anticataractogenic effects of topical captopril in diquat-induced cataract in rabbits. Free Radic Biol Med 12:251-61
Bhuyan, K C; Bhuyan, D K; Chiu, W et al. (1991) Desferal-Mn(III) in the therapy of diquat-induced cataract in rabbit. Arch Biochem Biophys 288:525-32
Bhuyan, K C; Bhuyan, D K; Podos, S M (1991) Free radical enhancer xenobiotic is an inducer of cataract in rabbit. Free Radic Res Commun 12-13 Pt 2:609-20
Bhuyan, D K; Bhuyan, K C (1991) Oxy radicals in the eye tissues of rabbits after diquat in vivo. Free Radic Res Commun 12-13 Pt 2:621-7

Showing the most recent 10 out of 12 publications