title: DNA damage and antioxidant defense in peripheral leukocytes of patients with Type I diabetes mellitus.
abstract: We determined relationship among DNA damage, nitric oxide (NO) and antioxidant defense in leukocytes of patients with Type 1 DM. DNA damage was evaluated as strand breakage and formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites by the comet assay in DNA from leukocytes of the subjects. Nitrite level, as a product of NO, superoxide dismutase (SOD) activity and glutathione peroxidase (G-Px) activity of the leukocytes were measured by spectrophotometric kits. Serum glucose level and glycosylated haemoglobin (HbA(1c)) were higher in the patients, as expected. Differences in measured parameters between controls and patients were assessed in men and women separately. There was no significant difference between patient and control groups in neither men nor women for nitrite level. Strand breakage and Fpg-sensitive sites were found to be increased, SOD and G-Px activities of the leukocytes were found to be decreased in both men and women of patient group as compared to their respective controls. Significant correlations were determined between strand breakage and HbA(1c) (r = 0.37, P<0.05); Fpg-sensitive sites and HbA(1c) (r = 0.59, P<0.01); Fpg-sensitive sites and glucose (r = 0.45, P<0.02); Fpg-sensitive sites and SOD (r = -0.48, P<0.02); HbA(1c) and SOD (r = -0.50, P<0.02). In conclusion, impaired antioxidant defense in leukocytes of patients with Type 1 DM may be one of the responsible mechanisms for increased DNA damage in those patients.
authors.affiliation: Department of Biochemistry, Cerrahpaşa Medical Faculty, Istanbul University, Istanbul 34300, Turkey. stare63@yahoo.com
authors.forename: Yildiz
authors.initials: Y
authors.lastname: Dinçer
authors.forename: Tülay
authors.initials: T
authors.lastname: Akçay
authors.forename: Hasan
authors.initials: H
authors.lastname: Ilkova
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Alademir
authors.forename: Gülşen
authors.initials: G
authors.lastname: Ozbay
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D020552:Comet Assay; D004249:DNA Damage; D043382:DNA-Formamidopyrimidine Glycosylase; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007962:Leukocytes / Q000201:enzymology*; D008297:Male; D009699:N-Glycosyl Hydrolases; D009573:Nitrites / Q000032:analysis; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D043382:DNA-Formamidopyrimidine Glycosylase; D005979:Glutathione Peroxidase; D006442:Glycated Hemoglobin; D009699:N-Glycosyl Hydrolases; D009573:Nitrites; D013482:Superoxide Dismutase