RNAL BLEEDINGAbstract. Traumatism is one of the urgent problems of today. Their structure is dominated by combined and multiple lesions with secondary damage to internal organs and the formation of multi- organ failure. Much more serious consequences arise in the case of direct impact of the traumatic factor on the body cavities. Under the conditions of traumatic damage to the abdomen, there is a direct impact of the impact energy on the internal organs and blood loss. However, until now there are no convincing data to what extent the presence of blood in the peritoneal space can deepen the manifestations of insuffi ciency of the organs of the gastrointestinal tract, in particular, the liver.Goal. To fi nd out the activity of lipid peroxidation in the liver, manifestations of cytolysis syndrome and endotoxicosis under the conditions of closed abdominal trauma complicated by internal bleeding.Material and methods. 132 sexually mature white male Wistar rats were used in the experiments. In experimental group 1, under thiopental sodium narcosis, TTS was simulated. In experimental group 2, external bleeding (20% of circulating blood volume) was additionally induced by transection of the femoral vein. In experimental group 3, also after TTS, bleeding was induced in a similar volume, which was administered intraperitoneally. After 1, 3, 7 and 14 days, the content of reagents to thiobarbituric acid (TBK-active products of POL) was determined in the homogenate of the liver of the experimental rats, in the blood serum – alanine aminotransferase activity (AlAT activity) and the content of the fraction of molecules with an average mass of 280 nm (MSM280). The probability of diff erences was assessed by the non-parametric Mann- Whitney test.The results. Applying only TTZ signifi cantly deepens the processes of lipid peroxidation in the liver, activates the processes of cytolysis and endotoxicosis. The content of TBK-active processes of LPO gradually increases with a maximum after 7 days, AlAT activity and the content of the MSM280 fraction in blood serum reach a maximum by the 3rd day of the experiment, followed by a decrease that does not reach the control level by the 14th day. Applying TT in combination with acute blood loss naturally leads to deepening of the studied processes. Compared with rats that were modeled only with TSH, the content of TBC-active products of LPO, ALT activity, and the content of the MSM fraction in blood serum signifi cantly increased. Comparison of the depth of violations under conditions of blood loss of diff erent origins. showed that the same volume of blood loss with blood fl ow into the intraperitoneal space compared to external blood loss is accompanied by signifi cantly greater violations of the studied indicators.Conclusions. Internal bleeding against the background of TTS, compared to blood loss of a similar volume after external bleeding, causes greater violations of the studied indicators of lipid peroxidation with the maximum manifestation after 3-7 days of the experiment, cytolysis – after 7 days, endotoxicosis – after 7-14 days.