Montiel F, Aranda A, Villa A, Pascual A
J Neurochem. 1986 Nov;47(5):1336-43. doi: 10.1111/j.1471-4159.1986.tb00762.x.
We have compared the effects of norepinephrine, forskolin, and dibutyryl cyclic AMP (Bt2cAMP) on the regulation of the cytosolic enzyme glycerol phosphate dehydrogenase (GPDH) in the C6 rat glioma cell line. Forskolin and Bt2cAMP elicit a dose-dependent increase in the levels of the enzyme that was, however, unaffected by norepinephrine. The half-maximal effect of forskolin was obtained at 7-8 microM, and the effect was maximal at 30 microM. Dexamethasone at a 50 nM concentration produced a two- to sixfold induction of GPDH after 48 h. The combination of dexamethasone with forskolin or Bt2cAMP leads to an elevation in GPDH levels that is higher than that produced by one of the compounds alone. This potentiation is found when both agents are added together with or after the glucocorticoid. The increase in uninduced and dexamethasone-induced GPDH activity was blocked by cycloheximide and actinomycin D, indicating that de novo protein and RNA synthesis are required. The activity of cytosolic lactate dehydrogenase activity did not change after incubation with dexamethasone, but increased with forskolin or Bt2cAMP.
我们比较了去甲肾上腺素、福斯高林和二丁酰环磷腺苷（Bt2cAMP）对C6大鼠胶质瘤细胞系中胞质酶磷酸甘油脱氢酶（GPDH）调节的影响。福斯高林和Bt2cAMP可引起该酶水平呈剂量依赖性增加，然而，去甲肾上腺素对此无影响。福斯高林的半数最大效应在7 - 8微摩尔时获得，在30微摩尔时效应最大。50纳摩尔浓度的地塞米松在48小时后可使GPDH诱导增加2至6倍。地塞米松与福斯高林或Bt2cAMP联合使用会导致GPDH水平升高，且高于单独使用其中一种化合物时产生的水平。当两种药物与糖皮质激素一起添加或在其之后添加时，均可发现这种增强作用。环己酰亚胺和放线菌素D可阻断未诱导和地塞米松诱导的GPDH活性增加，表明需要从头合成蛋白质和RNA。与地塞米松孵育后，胞质乳酸脱氢酶活性未发生变化，但福斯高林或Bt2cAMP可使其增加。
