The retention of metallic radionuclides in experimental abscesses in rats.

The retention of 67Ga, 203Hg, 175 + 181Hf, 239Pu and 241Am in turpentine-induced abscesses and in normal muscle has been studied in rats for periods of up to 126 days after radionuclide injection (129 days after turpentine). The results show that although the uptake of 203Hg is about 7 times greater in the abscess than in control muscle, the half time of the nuclide is similar in both tissues, T1/2 = 5 days. The remaining radionuclides studied all show a similar retention time in control muscle, average T1/2 = 12.5 days, and a more prolonged retention in the abscess tissue, average T1/2 = 47 days, although in both control and abscess tissue the uptake of the radionuclides showed quite large metal-specific variations. It is concluded that for radionuclides which are transported on transferrin in the blood and which deposit in lysosomes within cells a common metal clearance mechanism may operate in normal muscle and a second general mechanism may operate in abscess tissue. The radionuclide concentration difference between normal and abscess tissue ranged from 8 (67Ga) to 27 (239Pu); thus the radiation dose delivered to the inflamed tissue was between about 30 and 100 times greater than in normal muscle.