Action of 5-Bromodeoxyuridine on the Induction of Haemoglobin Synthesis in Mouse Leukaemia Cells resistant to 5-BUdR

The thymidine analogue 5-bromodeoxyuridine (BUdR) preferentially inhibits the synthesis of those proteins which are characteristic of the differentiated state of a cell1-5. The observed effects of BUdR have been suggested to be due to its incorporation into DNA1,4,6 and or due to its interference with the synthesis of carbohydrates needed for the formation of some cell membrane constituents7,8. There has been no direct evidence, however, in favour of any hypothesis and nothing is known about the actual mechanisms involved.