[57Co-bleomycetin pharmacokinetics in the body of mice with LIO-1 lymphosarcoma]

Pharmacokinetics of 57Co-bleomycetin was studied on mice with lymphosarcoma LIO-1. It was found that at early periods of intravenous administration of the labeled antibiotic, i.e. within the period from 5 minutes to 1 hour its higher levels are detected in the liver, kidneys, blood serum, lungs, intestine and tumor. At later periods the drug levels in the organs and tissues gradually decrease and by the 72nd hour the concentration of 57Co-bleomycetin in the blood serum appears to be 30 times lower as that after 5 minutes. In the muscles and tumor its concentrations by that period are 15 and 2 times lower respectively. Radiometry of the animals showed that within the first 24 hours more than 85 per cent of 57Co-bleomycetin was excreted from the mice.