Characteristics of redox status in male and female rats with experimental diabetes mellitus, Guerin's carcinoma and associated pathology

Taking into account cancer and diabetes comorbidity, the role of free radicals in these conditions and the dependence of pathological processes on the gender of animals, the aim of the study was to examine lipid peroxidation (LPO) intensity and the activity of the key antioxidant enzyme superoxide dismutase (SOD) in the heart, kidneys, liver, and in tumors of male and female rats with diabetes mellitus (DM), Guerin's carcinoma (GC) or both diseases. Materials and Methods. The study included 80 white nonlinear male and female rats (180-220 g). The animals were divided into 4 groups, each group included 10 animals (either male or female). At the time of GC inoculation, the blood glucose level in animals with alloxan diabetes was 25.4±1.2 mmol/L. The authors used conventional spectrophotometric methods to examine the content of malondialdehyde (MDA), diene conjugates (DC), and SOD activity. Statistical analysis was performed using Statistical analysis software Statistica 10.0. Results. The most pronounced changes in the studied parameters were found in the heart of female rats with isolated GC and associated diabetes mellitus: more than a threefold increase in MDA, a significant increase in DC against the background of an increase in SOD activity (by 5.5-6.3 times in comparison to intact animals). The amount of MDA in GC tissue depended on the tumor size: the maximum increase in both parameters was observed in male rats with GC growth and associated DM. Conclusion. The changes in the content of LPO products and SOD activity in the heart, kidneys, and liver of rats with diabetes mellitus and tumor growth depend on the type of the examined tissue and the gender of the animals. Disorders of the redox status found in the heart tissue can make a significant contribution to cardiopathology, which is often observed in diabetes mellitus and malignant tumor growth.