Tashima Y, Mizunuma H, Shima H, Kobayashi R, Tanaka S, Maeda N, Kumegawa M
J Biochem. 1984 Sep;96(3):805-13. doi: 10.1093/oxfordjournals.jbchem.a134898.
In fetal mouse liver fragments maintained in organ culture, the activities of fructose 1,6-bisphosphatase and glucose 6-phosphatase are elevated in the presence of dibutyryl adenosine 3',5'-monophosphate (Bt2-cAMP). Isobutyl-1-methylxanthine at 2.5 mM increased the two enzyme activities. The enzyme activities returned to the normal levels following removal of Bt2-cAMP from the culture medium. Glucagon at concentrations from 10(-11) M to 10(-6) M induced both enzyme activities. The developmental increases in the two gluconeogenic enzymes are supported by cyclic AMP elevated by glucagon. Only at unphysiologically high concentrations did prostaglandin-E1 show weak stimulatory effects. alpha-Adreno-agonists did not stimulate the enzyme activities. Actinomycin D and cycloheximide reduced the enzyme activities stimulated by Bt2-cAMP. Both inhibitors and removal of Bt2-cAMP prevented the incorporation of [3H]leucine into the bisphosphatase. The kinetic properties, subunit-size, and antigenic nature of the bisphosphate showed that the type of enzyme induced by Bt2-cAMP in vitro is identical to the adult liver type. The results are interpreted as indicating that cyclic AMP acts at certain sites in the syntheses of these two gluconeogenic enzymes in the fetal mouse liver.
在器官培养中维持的胎鼠肝组织块中，在二丁酰腺苷3'，5'-单磷酸（Bt2-cAMP）存在下，果糖1,6-二磷酸酶和葡萄糖6-磷酸酶的活性升高。2.5 mM的异丁基-1-甲基黄嘌呤增加了这两种酶的活性。从培养基中去除Bt2-cAMP后，酶活性恢复到正常水平。浓度为10（-11）M至10（-6）M的胰高血糖素诱导了这两种酶的活性。这两种糖异生酶的发育性增加得到了胰高血糖素升高的环磷酸腺苷的支持。仅在非生理性高浓度下，前列腺素-E1才显示出微弱的刺激作用。α-肾上腺素能激动剂不会刺激酶活性。放线菌素D和环己酰亚胺降低了Bt2-cAMP刺激的酶活性。这两种抑制剂以及去除Bt2-cAMP都阻止了[3H]亮氨酸掺入二磷酸酶中。二磷酸酶的动力学性质、亚基大小和抗原性质表明，Bt2-cAMP在体外诱导的酶类型与成年肝型相同。结果被解释为表明环磷酸腺苷在胎鼠肝中这两种糖异生酶的合成中的某些位点起作用。
