The changes in the parameters of antioxidant system (AOS) and energy metabolism of rats that have insulin resistance (IR) complicated by iodine deficiency (ID) have been analyzed in the paper. 90 rats-females have been investigated. They have been divided into three experimental groups: animals with ID, IR and IR complicated with ID. The state of ID has been reproduced by keeping the rats on two-month iodine-deficient diet. In order to simulate IR, a 10 % solution of fructose have being added into the drinking water of animals during 8 weeks. The activity of catalase (K), ceruloplasmin (Cp), superoxide dismutase (SOD), glutathione peroxidase (GP), glutathione reductase (GR) and saturation of transferrin by iron (FTr) has been found in AOS of serum. Studying of energy metabolism has been based on the activity of succinate dehydrogenase (SDH), malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) in blood serum.. It has been found that the development of ID has been accompanied by the changes of the AOS, primarily, the decreasing activity of GP (by 57.90 %) and GR (by 76.47 %) relatively to the initial indexes. Iodine deprivation has led to the changes of the system of cell energy supply, that has been manifested by a significant decrease of LDH activity.
Two straightened changes in the antiradical defense components have been found in the rats with IR. Thus, K activity has been lower by 66.73 %, while the GP activity has increased by 63.16 % comparely to the similar indexes in animals of the control group. The development of hyperglycemia has led to the disbalance of energy supply system. In particular, the activity of SDH and LDH has been decreased by 57.66 % and 97.58 % respectively in animals with IR, while the background of the activity of MDH has increased by 62.81 % relatively to the initial data. IR complicated by ID has led to the increasing of the activity of GP in 5,63 times, GR - in 4,50 times, on the contrary, the background of FTr has been decreased by 47,62 % in animals with iodine deprivation. In this case, the activity of SOD and CP in rats from the 3rd research group has been on 19.89 % and 46.96 % less than in in the conditions of isolated IR.
The changes in the system of energy metabolism of animals with endocrine pathology have been manifested by the suppression of serum dehydrogenases activity. In particular, the decrease of the activity of SDH (by 90.38 %), MDH (by 9.92%) and LDH (by 97.12 %) relatively to the control indexes, SDH (by 87.91 %) and LDH (by 45.93 %) relatively to the data about the rats with ID, SDH (by 71.45 %) and MDH (by 44.67 %) comparely to the rats with IR has been found. The predominant decrease of the activity of investigated enzymes in the energy balance can be regarded as a sign of the insufficient oxygen supply of the tissues and a malfunction of the biotransformation energy system that undergo more pronounced changes in the case of combined endocrine disorders.
Thus, the development of ID and IR has been accompanied by the changes of the activity of enzymes of antioxidant defense and macroenergy synthesis. The combined endocrine pathology has led to more severe changes of the studied parameters, that may indicate a violation of prooxidant- antioxidant homeostasis and cellular energy metabolism under the conditions of hyperglycemia against the background of ID. Violations of energy supply against the background of the suppression of antioxidant defense can be a pathogenic factor of diabetes mellitu disorders, the formation of which can potentiate ID.
Article recieved: 15.05.2018
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