Percent of total dose associated with blood cells and tissues following IV administration of ¹²⁵I-rmTPO. Mice received a single IV bolus injection of ¹²⁵I-rmTPO or ¹²⁵I-rmTPO + 8.8 μg rmTPO and were killed 3 hours later. Citrated blood was collected and the amount of radioactivity associated with the blood cells determined per animal based on 1.95 mL total blood volume. Whole tissues were dissected and the amount of radioactivity associated with each tissue determined. The data were expressed as percent of total dose. Black bars represent ¹²⁵I-rmTPO and striped bars represent ¹²⁵I-rmTPO + 8.8 μg rmTPO. *Indicates values are significantly different (P < .05).