ACTIVITY OF FREE RADICAL OXIDATION AND CYCLOOXYGENASE EXPRESSION IN RATS KIDNEYS UNDER EXPERIMENTAL THERAPY OF OXALATE NEPHROLITHIASIS WITH TETRAPEPTIDE Leu-Ile-Lys-Met

The aim of the study was to investigate the effect of Leu-Ile-Lys-Met tetrapeptide on the activity of free radical oxidation (FRO) and the level of cyclooxygenase-1 (COX-1) and COX-2 expression in rat kidney with experimental oxalate nephrolithiasis. Material and methods. The experiments were carried out on 30 male rats Wistar runoff, divided into 3 groups: the comparison group (10 intact rats), the control group (6 weeks of experimental oxalate nephrolithiasis simulation, n = 10), the experimental group (6 weeks of experimental simulation oxalate nephrolithiasis + oral administration of Leu-Ile-Lys-Met tetrapeptide at a dose of 12 mg/kg from the 3rd to the 6th week, n = 10). The oxalate nephrolithiasis was simulated according to conventional ethylene glycol model. COX-1 and COX-2 concentration in rat urine at baseline and after 6 weeks of experimental nephrolithiasis was determined by enzyme immunoassay using the prostaglandin-endoperoxide synthase 1 and 2 (PTGS 1, 2) kit from «Cloud-Clone Corp.». In rat kidney homogenate, the activity indicators of FRO processes were determined by common methods. Results and discussion. At the background of the Leu-Ile-Lys-Met tetrapeptide, free radical kidney damage was weakened, which was manifested in the complete absence of morphological signs of nephrolithiasis, decrease of thiobarbituric acid-reactive product concentration and overall prooxidant activity as compared to the control group; glutathione peroxidase activity, on the contrary, increased by 1.5 times.