[VIOLATION OF THE PROOXIDANT-ANTIOXIDANT BALANCE IN THE SPLEEN TISSUE UNDER EXPERIMENTAL CARCINOGENESIS].

This study was devoted to the investigation of antioxidant homeostasis in spleen tissue of white rats in the dynamics of development of colon adenocarcinoma induced by the introduction of sym-dimethylhydrazine (DMH). The effectiveness of the antioxidant barrier (Cu,Zn-superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, reduced glutathione) and oxidative damage products (TBARS, advanced oxidation protein products, diene and triene conjugates, Schiff bases) were measured in the homogenate of spleen tissue. A violation of the redox balance due to the accumulation of lipid peroxidation products, a decrease in the activity of antioxidant enzymes and antioxidant mediators of non-enzymatic nature was established. The development of oxidative stress leads to disruption of the synthesis of glutathione peroxidase and glutathione reductase in the endoplasmic reticulum, i.e., to inhibition of the functional activity of the glutathione-dependent unit of the antioxidant system. DMH-induced carcinogenesis is associated with enzymatic/non-enzymatic redox imbalance as well as increased oxidative damage to proteins and lipids. Evaluation of redox biomarkers can be potential diagnostic indicator of colon adenocarcinoma advancement.