69 children with acute (OGN) and 59 with chronic glomerulonephritis (CGN) hospitalized in the nephro-logic department were examined. Blood and urine for analysis in patients are taken during the period of activi-ty of OGN and exacerbation of CGN, for the first time the days of admission to the hospital. Patients with OGN and CGN showed distinct seasonal fluctuations in LPO activity (p <0.001), a significant increase in the phos-
pholipase activity of urine and blood compared to the control indices (p <0.001), a significant increase in the cytotoxic lipid lipophosphatidylcholine fraction (LFX) (p <0.001), a decrease in the level of phosphatidylcho-line (PX) (p <0.001), a reduction in mechanical resistance (p <0.001) and erythrocyte deformability (p <0.001). In the examined patients, the level of α-tocopherol (p <0.001) and the activity of superoxide dismutase
(SOD) (p <0.001), catalase and peroxidase in the blood (p <0.001) was decreased, while the activity of antiox-idant and antiperoxide enzymes in urine increased (p < 0.001). It has been established that in patients with acute respiratory depression and CGN in aggravation, the activity of lipid peroxidation is increased, the eryth-rocyte FLase activity of erythrocytes and A2 FLase decreases, the level of SOD of erythrocytes decreases, cata-lase and peroxidase activity of the blood, as well as the percentage of LFH in erythrocyte membranes, the me-chanical resistance and deformability decrease red blood cells