Distribution of polyoma virus in the organs of newborn Wistar rats after subcutaneous inoculation

Summary Polyoma virus of the Stuart Eddy strain was tritium-labelled by cultivating the virus in phosphate free Hepes buffered medium in presence of tritium labelled nucleotide triphosphates. The distribution of labelled virus in the organs and in the blood of newborn Wistar rats was examined at graded time intervals from two hours until 40 days after inoculation. The highest amounts of virus per organ was refound in the liver and the highest amount per mg organ weight in the spleen. The virus concentration in most organs exceeded by far the concentration found in the blood, indicating adsorption of virus in these organs. It was found that the distribution of tritium in the target organs for tumor appearance (kidneys and brain) did not differ basically from that in the non-target organs. As a consequence, the distribution of virus in the organs does not explain the fact that the kidneys and the brain are the predilection sites for tumor induction. Tritium labelling did not measurably influence the oncogenicity, infectivity and hemagglutinating activity of the virus.