Carbon dioxide metabolism in the Jensen and JA sarcomas in vitro.

A requirement for carbon dioxide or bicarbonate has been demonstrated for the growth and survival of the Jensen, JA-1, and JA-2 sarcomas in vitro. When the cells were grown in the presenee of C140~, isotope was isolated in incorporated aspartic acid, glutamic acid, and proline as well as in the purines and pyrimidines. Although the relative specific activity of the purines and thymine was approximately the same, it was much lower in cytosine and slightly higher in uracil. From this information carbonate-sparing experiments were performed, and uracil partially spared this requirement, whereas the other organic bases were inactive.