Antimitotic Action of 5-(2′-Bromoacetamido)-Uracil on the Ehrlich Ascites Tumor. ∗

Summary

1. A single intraperitoneal injection of 5-(2′-bromoacetamido)-uracil (BAU) into mice bearing the Ehrlich ascites tumor produced marked mitotic abnormalities which persisted for long periods and resulted in appearance of tumor cells with pycnotic nuclei. 2. This chromosomal damage could be prevented by injecting glutathione or cysteine simultaneously with BAU. 3. It was suggested that BAU might act as an alkylating agent via free radical formation. 4. Administration of a single dose of 5-fluorouracil temporarily decreased the concentration of ascites cells in ascites fluid and also the mitotic frequency, but no morphological alterations were observed in the tumor cells. 5. It was concluded that the mechanism of action of the above two 5-substituted uracils on Ehrlich ascites cells was different.