Биохимические показатели крови норок при жировом гепатозе

In recent years, in veterinary medicine, growing number of the hepatobiliary system pathologies, affecting negatively the animal organism physiological status, has become particularly relevant problem, leading to further study of the main markers, including biochemical ones, which allow diagnosing such pathologies even at an asymptomatic level

In the modern world, liver pathologies of a non-infectious nature, in particular, such as fatty degeneration of the liver (fatty hepatosis), are superior in percentage terms to absolutely all non-infectious pathologies in fur animals (and minks in particular) both in terms of the number of detections and in terms of coverage as well as the financial damage caused to producers

The main reason for the occurrence of fatty hepatosis (fatty liver) is either a violation of the norm of feeding during the fattening (winter) period, since high-calorie feeds with a high fat content are given, which creates a significant burden on the fat metabolism of the body as a whole and leads to pathological fat deposition in hepatocytes. On the other side use of low-quality feed in the diet of fur-bearing animals, contain fat oxidation products – aldehydes, ketones, low molecular weight acids, hydroxy acids, which have cytotoxic properties

The main goal of the study is to identify and analyze the main biochemical markers indicating the development of fatty hepatosis (fatty liver) in animals with specific clinical manifestations of such a pathology.

The experiments were carried out in 2022 at the Mermeriny fur farm (Mermeriny village, Kalinin district, Tver region). Palomino minks (Mustela vison Schreber, 1777) were chosen as model animals.

Before the study, the results of clinical examination recived at the fur farm were analyzed, after which, based on the anamnesis and physical examination, candidate animals (10 females and 10 males, age – 1 year) were selected with suspected fatty liver disease. Subsequently, the presumptive diagnosis was confirmed on the basis of clinical and biochemical studies.

Blood sampling from animals was carried out taking into account the rules of asepsis and antisepsis by cutting the tip of the tail into vacuum test tubes for biochemical analysis, improvacuter with a coagulation activator.

The content of the main biochemical parameters, such as total protein, albumin, total bilirubin, alkaline phosphatase, glucose, cholesterol, total bile acids, aspartate aminotransferase and alanine aminotransferase (with further calculation of the de Ritis coefficient) was determined on a biochemical analyzer URIT 8021A VET (URIT Medical Electronic Group Co., Ltd, China). The de Ritis coefficient was calculated as the ratio of the activity of serum aspartate aminotransferase and alanine aminotransferase, the amount of total bilirubin was determined by the colorimetric diazomethod according to Jendrashik-Cleghorn-Groff with sodium nitrate (JSC LenReaktiv, Russia), albumins - by the colorimetric method using bromcresol green (JSC LenReaktiv, Russia), total protein - by the biuret method based on a color reaction with copper sulfate (JSC LenReaktiv, Russia) in an alkaline medium. Cholesterol content was assessed by the standard Ilka method (manufacturer of the Ilka reagent, JSC LenReaktiv, Russia), glucose content, by the glucose oxidant method (manufacturer of glucose oxidase, LLC BioPreparat, Russia).

Statistical processing of the results was carried out in the Statistica 6.0 software. Mean values of indicators (M), standard errors of means (±SEM) were calculated.

Biochemical parameters of the blood of the studied groups are presented in Table 1. The lack of reliability calculation was due to the exploratory nature of the study and the absence of control groups.

Analyzing the data obtained, it can be concluded that males and females with suspected fatty hepatosis have a significant increase in alkaline phosphatase activity (one of the main biochemical markers of liver pathologies), minor pigment metabolism disorders, and there is also a violation of fat metabolism characteristic of this pathology. So, the indicator of alkaline phosphatase in fatty degeneration of the liver, on average, increases by 3-3,5 times (however, this indicator is difficult to consider as a high-prognostic indicator, since it tends to increase with any cytotoxic effect on hepatocytes); total bilirubin and cholesterol in minks increase slightly, the maximum increase in total bilirubin – by 54,85%, cholesterol - by 49,0%. It should be noted that cholesterol increases most significantly in males than in females, which is primarily due to their pronounced physiological tendency to deposit fat molecules.

Of the greatest interest is the mutual change in the activity of transaminases (ALT and AST) and their ratio. Transaminases, or transferases, are enzymes that catalyze chemical reactions of nitrogen metabolism, the main task of which is to transport amino groups to form new amino acids. Biochemical processes requiring their participation are carried out mainly in the liver. The liver has transaminases that synthesize and break down amino acids and convert energy storage molecules. Serum (non-cellular part of the blood) concentrations of these transaminases are usually low. However, if the liver is damaged, the membrane of the liver cells (hepatocytes) becomes more permeable and some enzymes enter the bloodstream. This indicator is a reliable prognostic marker by which one can judge the pathologies of the hepatobiliary system, but its values in various animal species are not fully understood. However, in this particular case, we noted a significant decrease in the de Ritis coefficient below the reference value, which indicates the presence of a pathological process specifically in the liver.

Thus, it is the change in these indicators relative to the reference intervals that should be considered as metabolic markers of liver pathologies in fur-bearing animals (minks in particular). Further studies require confirmation using morphological methods of research with the analysis of modern statistical methods.

One of the main problems in addressing the prevention and treatment of hepatopathy in fur animals is the lack of a relevant diagnostic base for the timely detection of this type of pathology. Most liver diseases pass latently or with nonspecific symptoms with the rapid development of pathological processes, while clinical and biochemical manifestations, although highly variable for further differentiation of the pathology, are at the same time considered the most promising and easily reproducible.