The Action of Chelating Agents on ²¹²Pb in the Blood: The Particular Value of the Steady State after ²²⁸Th Administration to the Beagle

Summary

An animal that has previously been injected with ²²⁸Th has a significant steady-state concentration of ²¹²Pb in its blood. The steady-state nature of the system offers several unusual aspects for the study of removal of lead from blood by chelating agents. First, the system regenerates itself so that one animal can be used for a series of studies. Second, since ²¹²Pb is being produced continuously, the temporal course of effect of the chelating agent can be followed. Third, since there is ²¹²Pb elsewhere in the animal, the effect of the chelating agent in removing lead from tissue deposits can be determined. This model applied to the beagle has been used to investigate the effect of amount of chelating agent administered, the comparative effectiveness of equimolar amounts of three chelating agents, and the comparative effectiveness of subcutaneous and oral administration.