Oxidative and carbonyl stress as a factors of the modification of proteins and DNA destruction in diabetes

Aim. To study the oxidative damage of biopolymers (proteins and nucleic acids) in blood of patients with type 2 diabetes mellitus (DM). Materials and methods. In the blood of 50 patients with DM and 25 patients without disorders of carbohydrate metabolism were estimated: the level of oxidized low-density lipoprotein (oxLDL) by immunochemical method, the content of SH-groups in plasma proteins, the activity of Cu, Zn-superoxide dismutase (SOD) in erythrocytes, the length of telomere in leukocyte DNA, the level of 8-hydroxy-2'-deoxygunosine (8-oxo-dG) in plasma and urine. Results and discussion. It is shown that in DM patients the level of oxLDL increases and the content of SH-groups in proteins and peptides of the blood plasma decreases, which indicates the development of oxidative stress. In addition, a carbonyl-dependent modification of erythrocyte SOD was detected in DM patients, as well as oxidative DNA destruction (decrease in telomere length in leukocytes and an increase in the level of 8-oxo-dG in blood plasma and urine). Conclusion. On the basis of the definition of a complex of correct indicators, a multiple oxidative modification of biopolymers of blood (proteins and DNA) was detected in patients with DM.