Becker J F, Bartholomew J C
Chem Biol Interact. 1979 Aug;26(3):257-66. doi: 10.1016/0009-2797(79)90029-2.
The inducibility of aryl hydrocarbon hydroxylase (AHH) by benzo[a]-pyrene (BaP) has been studied in synchronously grown cultures of mouse liver cells. These cells (NMuLi cl 8) have low basal levels of AHH which can be induced greater than 100-fold by BaP. Cells were synchronized in G1(G0) by serum starvation and in S by release from serum starvation in combination with excess thymidine. When released from G1(G0) by replating at lower cell density in fresh medium with 20% serum, cells began entering S with a lag of 12 h. Addition of BaP (1 microgram/ml) 8 h before serum stimulation, at the time of stimulation or 7.5 h after stimulation all gave similar induction kinetics: the AHH activity peaked as the cells began entering S regardless of when the BaP was added. Cells blocked in various parts of S by excess thymidine were inducible for AHH activity as efficiently as cells moving through S and into G2. These results indicate that the inducibility of AHH is greater when cells are actively proliferating and may be a contributing factor to why growing cells are more sensitive to mutagenesis and transformation than quiescent cells.
在小鼠肝细胞同步生长培养物中，研究了苯并[a]芘（BaP）对芳烃羟化酶（AHH）的诱导作用。这些细胞（NMuLi cl 8）的AHH基础水平较低，BaP可将其诱导至100倍以上。通过血清饥饿使细胞同步于G1（G0）期，通过血清饥饿释放并结合过量胸苷使细胞同步于S期。当以较低细胞密度接种于含20%血清的新鲜培养基中从G1（G0）期释放时，细胞开始进入S期有12小时的延迟。在血清刺激前8小时、刺激时或刺激后7.5小时添加BaP（1微克/毫升），均呈现相似的诱导动力学：无论何时添加BaP，随着细胞开始进入S期，AHH活性均达到峰值。被过量胸苷阻滞在S期不同阶段的细胞，其AHH活性的诱导效率与穿过S期进入G2期的细胞相同。这些结果表明，当细胞活跃增殖时，AHH的诱导性更强，这可能是生长细胞比静止细胞对诱变和转化更敏感的一个促成因素。
