Oxidative modification of proteins and antioxidant status in blood of the rats with experimental acute generalized peritonitis against the background of streptozotocin-induced diabetes

Modern aspects of the pathogenesis of acute inflammation of the peritoneum that is concurrent with diabetes involves analysis of metabolic mechanisms, in particular peroxidaton of proteins – antioxidant defense. Therefore, the objective of our study was to examine the interrelation between the processes of free-radical oxidation of proteins and antioxidant system in the dynamics of development of acute generalized peritonitis against the background of streptozotocin-induced diabetes. The study was performed on 56 non-linear white mature male rats. Diabetes mellitus was modeled by a single intraperitoneal injection of streptozotocin (60 mg/kg). On the 14th day of the development of streptozotocin-induced diabetes, we injected 10% filtrated faeces suspension (0.5 mL) into the abdominal cavity, thus initiating acute generalized peritonitis. Oxidative modification of proteins in blood serum was studied using the I. F. Meshchyshen’s method and the condition of antioxidant protection was monitored according to the activities of superoxide dismutase, catalase, content of reduced glutathione, and the level of ceruloplasmin. The study of the parameters of free-radical oxidation of proteins and study of the condition of antioxidant system in blood of the rats with experimental acute generalized peritonitis against the background of streptozotocin-induced diabetes demonstrated that oxidative protein modification grew, while the parameters of the activity of antioxidant system were being inhibited, depending on the stage of acute inflammation of the peritoneum. We determined inverse correlation relationships between the products of free-radical oxidation of proteins and parameters of antioxidant system on the third and on the seventh days of modelling of combined pathology. Manifestation of acute generalized peritonitis concurring with streptozotocin-induced diabetes was accompanied by a gradual accumulation of the products of free-radical oxidation of proteins and exhaustion of the antioxidant defense during all stages of the development of acute inflammation of the peritoneum, peaking on the seventh day after administration of faecal suspension (terminal stage of peritonitis). The observed inverse correlations between the levels of oxidative modification of proteins and the activity of superoxide dismutase, catalase, reduced glutathione, and ceruloplasmin on the third and on the seventh days of modelling of combined pathology indicate a predictive role of the processes of free-radical oxidation of proteins in exhaustion of antioxidant-defense resources.