ACTIVITY OF THE THIOREDOXIN SYSTEM IN THE LIVER OF RATS UNDER CONDITIONS OF PARTIAL HEPATECTOMY AFTER TOXIC INJURY

The work is dedicated to evaluating the activity of thioredoxin, thioredoxin reductase, and selenocysteine β-lyase in the cytosolic fraction of rat liver under conditions of partial hepatectomy after toxic injury by acetaminophen. The experiments were carried out on white non-linear rats, which were divided into two groups by the method of randomization: control animals, which received partial hepatectomy according to the Mitchell and Willenbring method (C/PH), and rats, which had partial resection of 2/3 of the liver tissue following acute toxic injury by acetaminophen through prior two-day administration at a dose of 1250 mg/kg of animal body weight (TI/PH). The study was performed at 0 hours (control), 24 hours (initiation phase), 48 hours (proliferative phase), 72 hours (termination phase), and 168 hours (distant period) after partial hepatectomy. The performance of partial hepatectomy after acetaminophen-induced injury modeling (TI/PH) is accompanied by a statistically significant decrease in thioredoxin activity in liver cells at the initial stages of regeneration (24 h and 48 h) compared to control values (0 h). The established changes occur against the background of suppression of selenium-dependent thioredoxin reductase and selenocysteine β-lyase activities during the initiation period (24 h), active cell proliferation (48 h), and termination (72 h). Depletion of the functional reserves of the thiol-dependent thioredoxin redox system and the suppression of selenide production efficiency, due to the demonstrated impairment in the conversion of organic selenium forms involving selenocysteine β-lyase in animals with acetaminophen-induced injury following partial hepatectomy (TI/PH), can be considered one of the factors reducing the regenerative potential of the liver under conditions of toxic injury. Keywords: thioredoxin, thioredoxin reductase, selenocysteine β-lyase, partial hepatectomy, acetaminophen, toxic injury, liver