Hydroxyurea does not prevent synchronized G1 chinese hamster cells from entering the DNA synthetic period

摘要: Using very high concentrations of radioactively labeled thymidine, we show that synchronized G/sub 1/ cells treated with hydroxyurea entered the DNA synthetic period at a time and rate indistinguishable from untreated cells, although synthesis was greatly reduced in drug-treated cultures. The synthesized presence less than or equal to 1 x 10/sup 7/ daltons, all which could be chased into bulk approximately 3.5 8/ daltons within 3 hr after removal hydroxyurea. Hydroxyurea are apparently not blocked 1//S boundary but S phase itself.