RED CELL AND PLASMA RADIOACTIVE COPPER IN NORMAL AND ANEMIC DOGS.

Following ingestion of radioactive copper by the dog, the metal appears quickly in the plasma, the concentration reaching its peak in from 2 to 5 hours, after which it falls abruptly. Demonstrable amounts are still present after 2 days. The radioactive copper likewise appears rapidly in the circulating red blood cells, and there is a slow but gradual increase in its concentration over a 2 day period. It is suggested by the data that in the animals in which hematopoietic activity is accelerated the uptake of radio-copper is somewhat more extensive. The possibility that this is due to greater adsorption by the new red cells in these instances is not ruled out.