FEATURES OF THE DYNAMICS OF LUNGS’ CATALASE ACTIVITY IN POST-TRAUMATIC PERIOD ON THE BACKGROUND OF EXPERIMENTAL ISCHEMIA-REPERFUSION OF THE LIMB

Abstract

Summary. The antioxidant protection system is both a sensitive indicator of the increase of reactive oxygen species and a primary front against peroxidation. Ischemic-reperfusion syndrome (IRS), which occurs in an organ that has undergone temporary ischemia, is studied very actively, but the systemic consequences in organs localized far from ischemia are no less important. Establishing the tissue catalase activity at different stages of the reperfusion period is important for understanding the mechanisms of further treatment of limb ischemia-reperfusion, combined with massive blood loss.

The aim of the study – to investigate the activity of catalase in 10 % of the lung homogenate in different periods of development of limb IRS.

Materials and Methods. 260 white adult male rats were used (200 –250 g) and divided into 5 groups: control, EG-1 – simulation of isolated ischemia-reperfusion (IR) of the limb, EG-2 – simulation of isolated heavy blood loss, EG-3 – a combination of limb IR with blood loss, EG-4 – modeling of isolated skeletal injury of the thigh, EG-5 – a combination of limb IR and skeletal injury. Catalase activity was established in 10 % lung homogenate.

Results. When comparing the degree of inhibition of catalase activity between groups with modifications of the experimental intervention, it was found that the presence of IR worsened the course of both isolated blood loss and isolated skeletal injury of the limb. Thus, after 1 h in EG-3 catalase activity was lower compared to EG-1 3.5 times, and compared with EG-2 by 29.2 %. On day 1 in EG-3 catalase activity was lower compared to EG-1 and EG-2 6.4 times and 38.5 %, respectively. On day 3, which was critical for the degree of depression in EG-3, the activity rate enzyme was lower than EG-1 and EG-2 by 9 times and 24.6 %, respectively. The expressed suppression was noted and in the following periods when on the 7th day the indicator of EG-3 was lower than data of EG-1 and EG-2 in 7.4 times and on 32.4 %, and on the 14th day remained lower, in comparison with EG-1 and EG-2 6 times and 43.1 %, respectively. As for the effect of IR on the consequences of skeletal trauma, which in itself also reduced the activity of lung catalase, on day 3, the EG-5 was lower than the data of EG-1 and EG-4 by 3.4 times and 22.3 %, respectively, while on the 14th day remained reduced, compared with EG-1 and EG-4 in 2.9 times and 30.3 %, respectively.

Conclusions. The experimental study confirmed that ischemia-reperfusion of the limb, in addition to local effects on the limb, has a systemic pathogenic effect on the body, which is especially dangerous in conditions of massive blood loss from the main vessel of the limb, as well as in combination with skeletal trauma. In this case, if isolated ischemia-reperfusion stimulated catalase activity of the lungs, the combination of IR with hemic hypoxia or trauma led to significant depression in the antioxidant defense system of the studied organ.