Optimum marker selection of acute liver damage in rats in the experiment

Relevance. Assessment of liver damage and functional state is one of the leading tasks of clinical and laboratory diagnostics. Traditionally used methods for determining the activity of a number of indicator enzymes in blood with relative organ-specificity, such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, sorbitol dehydrogenase, alkaline phosphatase, and γ-glutamyl transferase, have low specificity for liver diseases. In this regard, the determination of the optimal marker of acute liver injury is an urgent problem. Aim. The purpose of the study is to determine the dynamics of changes in liver damage markers in rats at different periods of reperfusion after 20 minutes of ischemia in order to select the indicators that most informatively characterize the state of test-animals under conditions of correction of ischemia-reperfusion syndrome. Materials and methods: the study was performed on 120 white nonlinear male rats weighing 200–250 grams. The animals were divided into 8 groups of 15 test-animals; all of them were simulated liver ischemia by clamping the analog of the hepatoduodenal ligament with a vascular clamp for 20 minutes. Then, blood was taken from different groups of rats at different reperfusion times – 5, 15, 30, 60, 120, 180 minutes, 8 hours and a day. In the blood plasma of laboratory animals, the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), glutathione transferase (GST), and lactate concentration were determined. Results: the results obtained allowed us to characterize two main peaks of indicators: a 5-minute period after restoration of blood flow – the maximum activity of glutathione transferase and lactate concentration, increased by 3.9–4.7 times; 60–180 minutes of reperfusion is the peak of aminotransferase activity, a significant increase in the activity of which begins 60 minutes after the restoration of blood flow and reaches its maximum by the 3rd hour of reperfusion, and LDH, the peak of which is recorded already by the 60th minute of revascularization. At the same time, after 8 hours of reperfusion, an obvious tendency for a decrease in all studied parameters was determined, which ends a day after modeling ischemia with a decrease to the level of control values. Conclusion: the assessment of organ damage in the ischemic period and the anti-ischemic effect of metabolic drugs can be carried out with the determination of an increase in lactate concentration and glutathione transferase activity almost immediately after restoration of blood flow. The development of injuries during the reperfusion period is more expedient to assess by determining AST, ALT and LDH after a 3-hour period of blood flow restoration, at which time the maximum values of markers are recorded under the condition of 20-minute total liver ischemia.