DISTURBANCE OF PRO-OXIDANT-ANTIOXIDANT BALANCE IN RATS WITH CEREBRAL ISCHEMIA

Excess of reactive oxygen can lead to membrane damage, accumulation of lipid, protein, and nucleic acid oxidation products, deficiency of reduced pyridine nucleotides and phospholipids of mitochondrial membranes, and then to electrolyte imbalance, mitochondrial swelling, uncoupling of oxidation and phosphorylation processes, and ischemic neuronal death. Thus, the study of oxidative stress and antioxidant system activity is relevant. The aim of the study is to examine the changes in the pro-oxidant-antioxidant balance in rats with ischemic brain damage of different degrees of severity (subtotal and total cerebral ischemia). Materials and Methods. The experiments were performed on 30 male outbred white rats weighing 260±20 g in compliance with the requirements of the Directive of the European Parliament and the Council of the European Union No. 2010/63/EU of September 22, 2010 on the protection of animals used for scientific purposes. Results. A more significant decrease in the content of total SH-groups of proteins and glutathione (by 58 (51; 64) % (p<0.05)), and GSH concentration (by 29 (19; 35) % (p<0.05)) was observed under 24-hour subtotal brain ischemia (SBI) compared with 1-hour SBI. Changes in the glutathione peroxidase activity were multidirectional: in 1-hour SBI, the activity increased by 12 (9; 18) % (p<0.05compared to the control level, and in 24-hour SBI, it decreased by 74 (67; 81) % (p<0.05). In 1-hour SBI, the content of total SH-groups of proteins and glutathione was higher by 60 (54; 65) % (p<0.05), and GSH concentration was higher by 42 (39; 56) % (p<0.05) compared with 1-hour total brain ischemia (TBI). The content of products that react with thiobarbituric acid increased by 59 (51; 63) % (p<0.05). In 24-hout SBI, the content of total SH-groups of proteins and glutathione was higher by 36 (29; 45) % (p<0.05), and GSH concentration was higher by 63 (59; 75) % (p<0.05) compared with 24-hour TBI. The content of products that react with thiobarbituric acid increased by 83 (78; 91) % (p<0.05). The glutathione peroxidase activity in TBI was equal to zero. Conclusions. Thus, the most pronounced disturbances in the pro-oxidant-antioxidant balance were observed in 24-hour TBI. Similar, but less pronounced disturbances were observed in 24-hour SBI.