In vivo Release of Radiocarbon from Labeled Ehrlich's Ascites Carcinoma Cells

Summary

Ascites cells labeled with radiocarbon from leucine-2-C¹⁴ were injected into mice. The amounts of radioactivity remaining in the acid-soluble, lipides, proteins and nucleic acids of the transplants for periods up to 5 days was measured. A marked loss of C¹⁴ from all of these components occurred within the first day but did not appear to be due to a reaction of the host against the inoculated cells. Between the 2nd and the 5th day a small but significant amount of the C¹⁴in the proteins and nucleic acids was lost per day. These results suggest that the transfer of labeled nitrogenous constituents from the tumor to the host tissues occurs to some extent. The possibility that these results may be due to the destruction of the cells must also be considered.