The hematobiochemical status of Wistar rat line under the bovine leukemia virus experimental infection

This study aimed to elucidate the ability of the bovine leukemia virus (BLV) to integrate into cells of heterologous organisms, in particular, Wistar rats, and examine the manifestations of the pathological process that could be seen in them.

Wistar rats - were divided into three groups. The first group (I) was fed milk of intact cows, the second (II) - milk of BLV-infected cows, and the third (III) - milk of cows, clinically BLV sick. Rats of all groups were divided into two subgroups: In the subgroup "a", there were adult rats, and in the subgroup "b", their offspring were included. At 3, 6, 9, and 12 months from the start of the experiment, the animals' blood of each group was examined by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay for the presence of BLV provirus and specific anti-leukemia antibodies. A general and biochemical blood test was performed; pathological changes in the internal organs were recorded.

Using the PCR, the BLV infection was established in all experimental rats, whose immune response was expressed in varying degrees. At the initial stage of the infection, offspring rats were born healthy. The rats of the control groups Ia and Ib were intact to the BLV throughout the experiment. The biochemical blood tests have shown several signs of intoxication, endocrine disorders, and development of malignant processes in the experimental animals. There are also signs of liver, kidney, and myocardial damages, regardless of whether milk is infected or the cows are clinically leukemic. By the time, the experimental rats developed persistent thrombocytosis with an increase in the average volume of the blood platelets, which may be evidence of the leukemia infection by the megakaryocytic type. The most pronounced character of the change was in the offspring generation.

Wistar rats can be considered as a suitable laboratory model to study the BLV pathogenesis. Rats are not BLV natural host, however, they developed the pathognomonic BLV infection symptoms when they were fed infected and leukemic cow's milk.