A comparative clinical study on the generation of nitrosative stress in cataractous lenses of smokers and non-smoker tobacco patients

Abstract

Aim: To quantify the levels of nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine in cataractous lenses of smokers and smokers who chewed tobacco in comparison with non-smokers and non-smokers who chewed tobacco. Study design: A total of 80 cataractous lenses from smokers, non-smokers, smokers with tobacco chewing habit, and non-smokers with tobacco chewing habit were collected from the patients who had enrolled in the Department of Ophthalmology, Mahatma Gandhi Medical College & Research Institute, Puducherry. Methods: Levels of nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine were quantified using commercially available enzyme-linked immunosorbent assay kits. Results: The mean concentrations of lens nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine are as follows: (a) smokers—112.01, 59.57, and 88.91 µmol/L; (b) smokers who chewed tobacco—175.15, 93.95, and 128.72 µmol/L; (c) non-smokers—76.15, 40.65, and 70.20 µmol/L; and (d) non-smokers who chewed tobacco—96.56, 52.87, and 83.88 µmol/L, respectively. Conclusion: Nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine at high levels are the major causative agents for cataractogenesis. The results of this study suggest that smoking and tobacco chewing habit generate nitrosative stress that could enhance the pathogenesis for early cataractogenesis.