WEIGHTINGS IN EXPERIMENTAL BLV INFECTION IN LABORATORY RATS
Authors:   Michurinsky State Agrarian University, Krasnikova E.S. , Radionov R.V. ,   Michurinsky State Agrarian University, Krasnikov A.V. ,   Michurinsky State Agrarian University, Svetozarova A.Yu. ,   Michurinsky State Agrarian University
Published: January 2022

The causative agent of bovine enzootic leukemia (BLV) has a tropism to lymphoid tissue and, due to the presence of these cell elements in various organs, can contribute to changes at the organ level, both due to hyperplasia and malignant proliferation of lymphoid elements, and due to inflammatory, dystrophic and atrophic processes in organs. The pathogen is able to infect heterologous organisms, in particular white laboratory rats of the Wistar line, in connection with which the goal of our studies was a comparative analysis of the vesometric characteristics of the internal organs of BLV-infected and intact rats, including relative to the body weight of animals in the dynamics of the experiment. Rats were divided into three groups. The first group of rats was fed milk of intact cows, the second - milk of BLV-infected cows and the third - milk of clinically treated cows with leukemia. The adult rats and their offspring, showing the presence of proviral DNA in the blood, were subjected to a quarterly study within a year of the start of the experiment. A comparative analysis of rat body weight dynamics showed that at the beginning of the experiment, animals actively gained weight, but by the end of the experiment, their body weight gain sharply decreased compared to the control, both in absolute and relative values, up to negative, and cachexia developed. This was most clearly seen in the offspring of the third group of rats, where positive dynamics were completely absent. The relative liver mass of the experimental rats was initially negative, and in the second half of the experiment - sharp positive dynamics. The dynamics of rat spleen relative weight initially had a negative tendency in rats treated with BLV-infected cow milk, which was replaced by positive by the end of the experiment. In rats of the third group, a persistent downward trend in organ volume was observed. The tendency to change the relative weight of the kidneys indicates an initial decrease in the index against the background of an increase in the body weight of animals, and then an increase in the relative weight of the organ in all experimental groups. The exception was the offspring of animals of the third group: their relative kidney weight increased in the dynamics of the entire experiment. In rats of the third group, the relative weight of the lungs increased sharply, which can be associated with the development of most of them with one- or bilateral pneumonia. The relative heart weight of animals in the experimental groups decreased 2.5-3 times compared to the control, despite the development of cachexia. Thus, experimental BLV infection of rats is accompanied by natural trends and changes in the ratio of body weight of animals and their internal organs, probably due to metabolic disorders and the development of various kinds of pathological processes: inflammatory, dystrophic, atrophic and proliferative.