Tissue distribution kinetics of 2,2',4,4',5,5'-hexachlorobiphenyl in ringdoves after oral dosing

Ring doves were provided contaminated food spiked with [(13)C]-2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) over a period of 63 days. Animals were sacrificed after 0.33, 0.5, 1, 2, 4, 8, 18, 36 and 63 days following access to contaminated food. At each time point, chemical concentrations in blood, liver, brain, gonad, adipose and remaining whole carcass was determined. Whole body concentrations of PCB 153 increased linearly with time over the experiment indicating that the birds did not reach steady state with their food after 63 days. Tissue/plasma concentration ratios were plotted as a function of time to determine time to inter-tissue steady state for fast and slowly perfused tissues. Liver, brain and gonad achieved steady state concentrations with plasma in less than 3 days, whereas fat and carcass tissues required 9.7 and 11.5 days, respectively. The results indicate that inter-tissue distribution kinetics for PCBs in birds is relatively rapid and completed within a little over a week following exposure to a contaminated diet.