a hydroxyurea-resistant mouse l-cell line was used to show that the degree of inhibition caused by bleomycin can be greatly enhanced if ribonucleotide reductase has been previously exposed in vivo or in vitro to agents , such as hydroxyurea , which destroy the tyrosine free radical of subunit m2 .
C0020402
resistant
C0035547
ribonucleotide reductase