PECULIARITIES OF BILIARY FUNCTION OF THE LIVER IN THE DYNAMICS OF POLYTRAUMA IN THE EXPERIMENT
Authors: Kozak D.V. 
Published: November 2020

Relevance. Severe trauma is accompanied by the development of multiple organ dysfunction and the insufficiency of internal organs. The dynamics of changes in the functional state of the liver didn't investigate fully. It is the central organ of detoxification of the body, whose activity occurs in close integration with other organs and systems of the body.
The objective is to find out the features of the biliary function of the liver in the dynamics of the developed model of polytrauma.
Materials and methods. Polytrauma was performed using 62 nonlinear white male rats weighing 180-200 g under conditions of thiopental-sodium anesthesia (40 mg 1kg-1 intraperitoneally). In surviving animals, the biliary function of the liver was studied in 2 h, 1, 3, 7, 14, 21, and 28 days after injury. For this purpose, the common bile duct was catheterized, and bile was collected for 1 hour in animals under thiopental-sodium anesthesia (60 mg kg-1). The rate of bile excretion and the concentration of total bile acids, cholesterol, direct and indirect bilirubin in the selected portion of bile were determined. Based on these data, the rate of excretion of the studied components of bile was calculated. Euthanasia of rats throughout the experiment was performed by total bloodletting from the heart after previous thiopental-sodium anesthesia (60 mg kg-1 intraperitoneally). The obtained digital data were subject to statistical analysis.
Results. In the conditions of experimental polytrauma, there is a violation of the biliary function of the liver. It is manifested in the period of an acute reaction to the trauma first (after 2 hours) by a significant it decreases, then (up to 1 day) development of polycholia - 1.52 times increased of bile secretion. Also increased excretion of the main components of bile, with their subsequent decrease to 7 days, development of the period of temporary improvement in 14 days with the repeated of exacerbation period in 21 days and approach to the norm - in 28 days.
The decrease in bile secretion corresponds to a period of shock, which is characterized by the centralization of blood circulation and reduced blood supply to the organs of the gastrointestinal tract. Increased bile secretion and excretion of main bile components in 1 day after a severe injury is associated with the increased biliary polarity of hepatocytes and unloading of the liver from endotoxins. It accumulates due to tissue damage, microcirculation, and hypoxia. Subsequently, the indicators of the biliary function of the liver changed by the identified patterns of lipoperoxidation deviations, antioxidant protection, cytolysis, and endogenous intoxication. The pathogenesis of biliary disorders is the damage of the endoplasmic reticulum membranes, where the synthesis of the main components of bile. As well as the development of edema of the organ, which prevents the outflow of bile.
Conclusion. The dynamics of the development of functional liver failure due to polytrauma coincides with the general pattern characteristic of the dynamics of other biochemical markers of traumatic disease. Namely: after 3 days of the post-traumatic period, there was a phase of maximum deepening of deviations of the studied indexes. After 7-14 days there was noted a phase of temporary improvement which is characterized by a change of indexes towards the norm. After 21 days there was a re-exacerbation of the pathological process. After 28 days the indexes changed towards the norm, but for most cases do not reach it.
This means that in a critical state of the body the organs and systems coupling is getting worse, which are remote from the site of injury. It can be considered as a factor of compensation and adaptation directed to the survival of the organism.