The article provides an overview of the most significant works of domestic and foreign authors devoted to the Ehrlich ascites carcinoma biological model. The analysis of the available literary sources showed that despite the long history of the existence of this model and its application in biomedical research, it has not yet become widespread in veterinary medicine. It should be noted that the Ehrlich ascites carcinoma model has a number of peculiarities that allow it to be used for the needs of veterinary medicine, in particular, experimental pharmacology at the stage of drug design and its preclinical testing. The high resistance of malignant cells and tumor survival in experimental animals, as well as the ease of its cultivation and relatively rapid tumor growth, make this model a convenient biological object for research. The effect of tumor cells on the body of the animal with a tumor leads to a change in a number of biochemical indicators of various tissues and organs, and a general toxic effect. In this case, an imbalance of the free-radical and antioxidant systems is observed, the body is exposed to oxidative stress. The immune system under the effect of Ehrlich ascites carcinoma also undergoes a number of changes. Thus, in response to the development of tumor-induced pathological processes, recruitment of immunocompetent cells and an antitumor immune response are observed, which at the same time is suppressed as carcinoma cells grow under the action of immunosuppressive physiologically active compounds produced by the tumor, escape of tumor cells from immunological surveillance and remodelling of immune cells in the tumor microenvironment. These processes lead to suppression of the immune system and as a result to the death of animals. These peculiarities make it possible to use the Ehrlich transplantable ascites carcinoma model for testing new veterinary drugs with potential antiblastoma, immunomodulatory, antitoxic properties, as well as medicinal formulations for restoring biochemical indicators and redox homeostasis under conditions of tumor-induced immunosuppression and chronic inflammatory process, and also to study the mechanisms of cell adaptation, including the immune system, under the action of carcinogenesis factors.

The aim of this work was to study the antimutagenic and DNA-protective effects of lipophilic cryofractions of bovine spleen and placenta in mice with mitomycin (MM)-induced genotoxicity. The effect of lipophilic cryofraction of bovine spleen (LCSC), lipophilic cryofraction of bovine placenta (LCPC) and their mixture in equal proportions (LCSPC) was studied. Outbred male mice were used in the experiments. The effects of a single administration of the substances separately and simultaneously with an intraperitoneal injection of MM were studied, as well as with three-time administration of the substances with an interval of 24 hours before the administration of MM relative to the negative and positive control groups. Afterwards, bone marrow samples were obtained from the animals for the micronucleus test and liver samples to determine the amount of mitochondrial DNA (mtDNA) damage in the 12S-16S and ND5 fragments. A single administration of LCSC, LCPC and LCSPC reduced the frequency of polychromatophilic erythrocytes with micronuclei (MNPCE) by 4.1, 3.9 and 2.4 times (p < 0.05), respectively, relative to the positive control group mice. With a course of administration of LCSPC, the frequency of MNPCE decreased by 31.3% (p < 0.05) relative to the positive control group. Administration of LCSC and LCSPC reduced the amount of mtDNA damage by 96.5 and 68.3% (p < 0.05), respectively, in the 12S-16S fragment relative to the positive control group mice. A course of administration of LCSPC before MM reduced the amount of mtDNA damage by 52.2% (p < 0.05) in the ND5 fragment. The antimutagenic effect of the studied cryofractions and the DNA-protective effect of LCSC and LCSPC in relation to mtDNA were revealed.

The problem of the birth of piglets with hypotrophy in the conditions of modern industrial pig farming causes great economic damage to this industry. Various forms of immunodeficiency are of great importance in the pathogenesis of hypotrophy. In this regard, an active search is underway for effective drugs for veterinary use to combat this pathology. One of these drugs is "Prostimul", which includes a signal peptide of the first type belonging to the cytokine group, as well as vitamins A, E, C. This article describes studies conducted on a group of hypotrophic piglets in order to determine the effect of the drug on immunological blood parameters, namely, an assessment of weasels, helmets, general IG, CEC, CT, SP, ETC. "Prostimuli" were administered twice to a group of hypotrophic piglets, on the first and third days of life in a dose 0.1 ml/kg of body weight. Blood samples for the study were taken on the 1st, 7th, 14th and 21st days. According to the results of the experiment, it was found that the double use of the drug "Stimul" contributed to the normalization of immune functions, which was already visible on the 7th day of the experiment. Thus, in hypotrophic piglets of the experimental group and normotrophics, the indicators of BASK, WEASEL, CEC and general IG were identical. In piglets with hypotrophy treated with the drug "Prostimul", there was a significant increase in the level of Ifn-α expression by days 7 and 14 – by 56.73 times compared with normotrophics. By day 14, an increase in the level of Tgf-β expression was also noted, indicating activation of immune processes in piglets with hypotrophy. Interestingly, by day 21, there was a decrease in the level of Ifn-α expression by 5.33 times compared with normotrophics after using the drug "Prostimul", which may indicate a decrease in inflammatory processes. Two-time use of the drug, in our opinion, should be considered optimal due to its stable effect throughout the experiment.

The article presents the data on immunological and morphological blood indicators of the newborn piglets. In the experiment, 20 sows of the 3rd-4th farrowing and the offspring obtained from them were selected. During the farrowing period, the piglets underwent clinical examination and weighing. The animals that did not reach 900 g were counted as hypotrophic piglets, the animals over 900 g – normotrophic, respectively. The first group (n=10) - hypotrophic piglets, and the second (n=10) - normotrophic piglets. Morphological blood examination in the hypotrophic piglets showed a decrease in the concentration of hematocrit and hemoglobin. The mean cell hemoglobin (MCH) assumed the values at the upper limit of the physiological norm, while the mean cell hemoglobin concentration (MCHC) in the normotrophics was by 17% higher than in the hypotrophics (p<0.05). The red cell distribution width (RDW) in the normotrophics was by 2.3 times higher than in the hypotrophics (p<0.05). When studying the immunological status of piglets, it was noted that the serum lysozyme activity in the hypotrophics was by 16% lower than in the normotrophics. The PAL in the normotrophics was 79.6±1.58, which was by 4.8% higher than in the hypotrophics (p<0.05). The PhN in the hypotrophics was by 11% less than in the normotrophics (p<0.05). The phagocytic index in the normotrophics was by 10% higher than in the hypotrophics (4.68±0.16) (p < 0.05). The PR of the normotrophics was by 1.5 times higher than that of the hypotrophics and was 3.03±0.2 (p<0.05).

In conditions of environmental distress and high anthropogenic load in agricultural activities, the task of maintaining the integrity of the animal genome arises. One way to solve this problem is to use drugs that have an antimutagenic effect. Pharmaceutical substances obtained from animal tissues are promising components of such drugs due to their antioxidant and radioprotective effects. In this regard, the purpose of this work was to study the genoprotective effect of hydrophilic cryofraction of the placenta (HCPC) and its mixture with hydrophilic cryofraction of the spleen of cattle (HCSPC) in mice with cytogenetic instability induced by the genotoxicant - mitomycin C (MMC). The genoprotective effect of the studied substances was assessed by reducing the frequency of micronuclei of polychromatophilic erythrocytes (MNPCE) in the bone marrow of mice after administration of MMC. The amount of damage in mitochondrial DNA (mtDNA) in mouse liver was also determined using quantitative polymerase chain reaction. As a result of the studies, it was established that HCPC and HCSPC did not exhibit toxic, mutagenic or DNA-damaging effects. A course of administration of HCPC and HCSPC caused a decrease in the frequency of MNPCE in the bone marrow of mice, with induced cytogenetic instability by 38.8 and 42.3% (p<0.05), relative to animals that were administered only MMC. With a course of administration of HCPC and HCSPC to mice that received MMC, a tendency was found to reduce the amount of mtDNA damage in the liver of mice. Thus, with a course of administration of HCSPC, a decrease in the amount of mtDNA damage was observed by 48.0% and 32.4% in two mtDNA fragments, respectively, relative to mice that were administered only MMC. Thus, with a course of administration of HCSPC, the tendency towards a DNAprotective effect was more pronounced relative to HCPC. These data indicate that HCPC and HCSPC have antimutagenic and DNA protective effects, which are more pronounced by HCSPC, probably due to the high antioxidant effect.

Maintaining the genetic stability of farm animals under adverse environmental conditions is often associated with the state of the antioxidant system and is a pressing issue in veterinary medicine. Our data demonstrate that pharmaceutical substances containing hydrophilic bovine spleen cryofraction (HBSC), lipophilic bovine spleen cryofraction (LBSC), and a mixture of lipophilic bovine spleen and placenta cryofraction (LBSPC) exerted an antimutagenic effect on the animals; however, the mechanism of this effect is far from fully understood. Therefore, the aim of this study was to investigate the effects of HBSC, LBSC, and LBSPC on certain parameters of lipid peroxidation (LPO) and antioxidant defense (AOD) in the blood of rats under conditions of oxidative stress induced by cyclophosphamide (CP). The effects of separate intramuscular administration of pharmaceutical substances at a dose of 0.5 ml/kg and their combined administration with an intraperitoneal injection of CP at a dose of 40 mg/kg in white laboratory male rats were studied. The effects of three doses of HBSC, LBSC, and LBSPC administered 24 hours apart before the CP injection were also studied. A single administration of HBSC, LBSC, and LBSPC did not induce statistically significant changes in lipid peroxidation and antioxidant protection in the blood of rats. A course of HBSC, LBSC, and LBSPC administered to rats reduced oxidative stress induced by CP due to its effect on antioxidant enzymes. This was reflected in a significant (more than 2-fold) increase in catalase activity, as well as glutathione peroxidase activity (by 71-79%), and a decrease in the levels of intracellular reactive oxygen species, diene conjugates, and ketodienes relative to animals in the positive control group. Thus, HBSC, LBSC, and LBSPC possessed an antioxidant effect, manifested by modulating the activity of the enzymatic component of the antioxidant system.