Effects of 5-Br-Deoxyuridine and 5-F-Deoxyuridine on Nucleic Acid Metabolism by Rabbit Bone Marrow Cells. ∗

Summary

The effects of 5-Br-deoxyuridine and 5-F-deoxyuridine on thymidine-2-C¹⁴, formate-C¹⁴, and P³² incorporation into rabbit marrow DNA in vitro were studied. 5-Br-deoxyuridine competitively inhibits incorporation of thymidine-2-C¹⁴ into rabbit marrow DNA, and is apparently used in lieu of thymidine for DNA biosynthesis. The bone marrow is quite sensitive to the action of 5-Br-deoxyuridine. 5-F-deoxyuridine does not appreciably affect incorporation of thymidine-2-C¹⁴ or P³² into marrow DNA or formate-C¹⁴ into RNA but greatly inhibits utilization of labeled formate for DNA synthesis indicating an interference with thymidine formation.