Kummel L, Pilkis S J
Department of Physiology and Biophysics, SUNY, Stony Brook 11794-8661.
Biochem Biophys Res Commun. 1990 Jun 15;169(2):406-13. doi: 10.1016/0006-291x(90)90346-o.
In the absence of hormone, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase mRNA rapidly declined to undetectable levels in primary cultures of rat hepatocytes. Dexamethasone increased mRNA levels and this effect was blocked by actinomycin D or cycloheximide. Insulin or thyroxine had no effect but potentiated the dexamethasone induction. Dibutyryl cyclic AMP decreased the stimulatory effect of dexamethasone at early times but after 24 hours the cyclic nucleotide increased mRNA levels compared with dexamethasone alone. It was concluded that expression of the bifunctional enzyme gene in hepatocytes is under a complex multihormonal control. Glucocorticoids are the most important transcriptional factor and their effect requires ongoing protein synthesis.
在缺乏激素的情况下，6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶的信使核糖核酸在大鼠肝细胞原代培养物中迅速下降至无法检测的水平。地塞米松可提高信使核糖核酸水平，而放线菌素D或环己酰亚胺可阻断此效应。胰岛素或甲状腺素无作用，但可增强地塞米松的诱导作用。二丁酰环磷腺苷在早期降低了地塞米松的刺激作用，但24小时后，与单独使用地塞米松相比，环核苷酸增加了信使核糖核酸水平。得出的结论是，肝细胞中双功能酶基因的表达受复杂的多激素控制。糖皮质激素是最重要的转录因子，其作用需要持续的蛋白质合成。
