| Abstract: | Hydroxyurea when injected intraperitoneally into rats either as a single dose or as three consecutive daily doses, markedly inhibited thymidine kinase activity in cerebellum on 7th day. The inhibitory effect of the drug was found to be both dose and time dependent. The drug has however, failed to exert any inhibitory action when added to the reaction mixture in vitro. It is concluded that the well established inhibition on DNA synthesis by hydroxyurea may not be solely due to its action on ribonucleotide reductase (EC 1.17.4.1) but probably due to its interference at several other sites including thymidine kinase. |
