title: Assessment of DNA base oxidation and glutathione level in patients with type 2 diabetes.
abstract: The first aim of the present study was to examine the relationship between reduced glutathione (GSH) level, a powerful cellular antioxidant, and oxidative damage to DNA; and secondly, to see the effect of glycemic control on oxidative DNA damage in type 2 diabetics. We determined GSH level and, using the comet assay, formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites which indicates oxidised guanine in freshly isolated blood from age-matched type 2 diabetics and controls. We found significant differences between men and women in the control group for both GSH and Fpg-sensitive sites. Therefore, we compared the controls and type 2 diabetics separately in men and women. GSH level of whole blood was found to be lower, Fpg-sensitive sites in leukocytes was found to be higher in the both type 2 diabetic men and women, as compared with their respective controls. When the diabetic group was divided into two groups as well-controlled diabetics and poorly-controlled diabetics with respect to glycosylated haemoglobine levels, it was found that Fpg-sensitive sites was significantly higher in the poorly-controlled diabetics than in the well-controlled diabetics in both the men and women. GSH level was lower in the poorly-controlled diabetics but not significantly. Fpg-sensitive sites were found to be moderately correlated with both glycosylated haemoglobine and GSH, and weakly correlated with glucose. Data indicate that decreased GSH level may be a contributory factor for enhanced oxidative DNA damage in type 2 diabetics; and chronic hyperglycemia derived from poorly-controlled diabetic conditions may induce oxidative DNA damage in these patients.
authors.affiliation: Department of Biochemistry, Cerrahpaşa Medical Faculty, Istanbul University, Turkey. stare63@yahoo.com
authors.forename: Yildiz
authors.initials: Y
authors.lastname: Dinçer
authors.forename: Tülay
authors.initials: T
authors.lastname: Akçay
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Alademir
authors.forename: Hasan
authors.initials: H
authors.lastname: Ilkova
mesh_terms: D020552:Comet Assay; D004247:DNA / Q000097:blood*; D004249:DNA Damage; D043382:DNA-Formamidopyrimidine Glycosylase; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis; D006147:Guanine / Q000737:chemistry; D006801:Humans; D006943:Hyperglycemia / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009699:N-Glycosyl Hydrolases / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D017382:Reactive Oxygen Species
chemical_list: D004247:DNA; D043382:DNA-Formamidopyrimidine Glycosylase; D005978:Glutathione; D006442:Glycated Hemoglobin; D006147:Guanine; D009699:N-Glycosyl Hydrolases; D017382:Reactive Oxygen Species