Pool of bile acids, its predictor functions and influence on the pathology of the hepatobiliary system (review)

Abstract

The creation of a highly effective model for diagnosing liver diseases of various genesis (including subclinical forms) in animals is one of the most urgent problems of veterinary science. Currently, there is a need to create more specific than "classical" tests for a clear differentiation of various pathologies of the hepatobiliary system, including diseases characterized by the absence of pathognomonic clinical or laboratory signs. One of the extremely promising predictors of such pathologies is bile acids (BA) and their pool. The main goal of the study is to search and analyze information from scientific publications dedicated to the study of the BA’s pool in various animal species, its changes in various pathologies of the hepatobiliary system and its diagnostic value. In English and Russian, in accordance with the recommendations of H. Snyder, various bibliographic databases (Elibrary, Pubmed, Scopus (Elsevier), Web of Science (Clarivat)) were searched for thematic publications by keywords with further highlighting the most cited ones. Articles published before 2015 were used only if they contained information critical to the better understanding of the topic, or it was not found in later publications. Based on the literature analysis, it can be concluded that liver diseases affect the synthesis and metabolism of bile acids. Therefore, BAs separately and their pool are studied and utilized as diagnostic and prognostic markers. However, it is not yet clear how the etiology of liver diseases affects the composition of bile acids. It should also be noted that in different animals there are differences in the BA pool, as well as in the details of their metabolism. This indicates differences in the specificity, affinity, and activity of enzymes involved in BA synthesis. Thus, BAs also affect the etiopathogenesis of diseases of the hepatobiliary system differently for each animal species, and, conversely, etiopathogenetic factors change the pool of BAs depending on the individual characteristics of the species.

Peculiarities of clinical and laboratory manifestations of hepatopathy: The path to medical consensus

“…The value of bile acids as a way to diagnose liver pathologies lies in their specificity and uniqueness. It is also worth noting their potential for use in monitoring the therapy of liver diseases [17][18][19][20][21][22][23][24].…”

“…From the data presented above, it is clear that hepatopathy in all animal species manifests itself as pathological syndromes of the same type. Cytolysis syndrome, which occurs as a result of the destruction of hepatocyte membranes and the release of cell contents into the intercellular space, manifests itself biochemically as an increase in the enzymes contained in the cytoplasm and mitochondria of liver cells (AST, ALT, and LDH) and an increase in the concentration of bilirubin (urobilinuria) [17][18][19][20][21][22][23][24]. Cholestasis syndrome, which occurs due to disorders in the biliary system of the liver, manifests itself in the form of increased alkaline phosphatase and an increase in bilirubin in the blood.…”

Etiology and pathogenesis of non-infectious hepatopathy in cattle under industrial production conditions

“…Animals that ingest these substances through the skin or mouth are at risk of developing liver disease. The use of pesticides, herbicides, and anti-parasitic drugs, as well as contact with industrial waste or contaminated water, can become a source of toxic hepatitis in cattle [19].…”

Clearance tests to assess liver function state of animals using compounds with high hepatic metabolism

“…Therefore, about 90% of medicinal substances are metabolized by 5 isoenzymes: CYP3A4, CYP2D6, CYP2C9, CYP2C19, and CYP1A2. [12][13] As a result, the original foreign substance changes its chemical structure, which may lead to changes in pharmacological activity. Metabolites may have a less active and less toxic effect on the body.…”