Sorimachi K
Biochim Biophys Acta. 1985 Jan 18;844(1):55-61. doi: 10.1016/0167-4889(85)90233-2.
Both phenolic and nonphenolic ring deiodinase activities in monkey hepatocarcinoma cells (NCLP-6E) were increased by addition of serum in a concentration-dependent manner: the stimulatory effect of serum was evident at a concentration as low as 1.5%, and was maximal at 5%. Lineweaver-Burk analysis showed that the increases in the deiodinase activities are due to the increase in Vmax, but not in Km. The addition of cycloheximide at concentrations ranging from 0.1 to 50 micrograms/ml inhibited the stimulatory effect of serum on phenolic ring deiodinase activity progressively. On the other hand, nonphenolic ring deiodinase activity was increased as much as 4-fold by the addition of 0.5-5 micrograms/ml cycloheximide together with 0.5% serum; a high concentration of the drug, 50 micrograms/ml, however, did not elicit such an increase. Actinomycin D at 5 micrograms/ml completely abolished the increase in nonphenolic ring deiodinase activity by serum or cycloheximide. In addition, actinomycin D inhibited the increase in phenolic ring deiodinase activity by serum in a dose-dependent manner at concentrations ranging from 0.05 to 5 micrograms/ml. It is concluded that phenolic and nonphenolic ring deiodinases are regulated by different mechanisms in monkey hepatocarcinoma cells (NCLP-6E).
在猴肝癌细胞（NCLP - 6E）中，酚环脱碘酶和非酚环脱碘酶的活性均随着血清添加量的增加而呈浓度依赖性升高：血清浓度低至1.5%时，刺激作用就很明显，在5%时达到最大值。Lineweaver - Burk分析表明，脱碘酶活性的增加是由于Vmax的增加，而非Km的增加。添加浓度范围为0.1至50微克/毫升的放线菌酮可逐渐抑制血清对酚环脱碘酶活性的刺激作用。另一方面，添加0.5 - 5微克/毫升放线菌酮与0.5%血清一起时，非酚环脱碘酶活性增加了多达4倍；然而，高浓度的该药物（50微克/毫升）并未引起这种增加。5微克/毫升的放线菌素D完全消除了血清或放线菌酮对非酚环脱碘酶活性的增加作用。此外，放线菌素D在浓度范围为0.05至5微克/毫升时，以剂量依赖性方式抑制血清对酚环脱碘酶活性的增加作用。得出的结论是，在猴肝癌细胞（NCLP - 6E）中，酚环脱碘酶和非酚环脱碘酶受不同机制调控。
