Seitz H J, Krone W, Tarnowski W
Acta Endocrinol (Copenh). 1977 Jun;85(2):389-97. doi: 10.1530/acta.0.0850389.
The effect of re-feeding glucose, protein or fat and the effect of insulin injection on the activity of hepatic phosphoenolpyruvate carboxykinase (GTP: oxaloacetate carboxy-lyase (transphosphorylating) EC 4.1.1.32), the concentration of hepatic cyclic AMP and the level of serum insulin was investigated in starved rats. Under all conditions examined the concentration of serum insulin was elevated to a high degree. However, only rats re-fed with glucose responded to the increase in serum insulin with a decrease in PEP carboxykinase activity, while the activity of the enzyme remained unchanged or was elevated after re-feeding protein or fat or after insulin injection, respectively. Since under all conditions there was a close correlation between cyclic AMP concentration and PEP carboxykinase activity, but not between the insulin level and enzyme activity, it is concluded that the hormone physiologically regulates PEP carboxykinase activity by decreasing the intrahepatic cyclic AMP concentration rather than by the postulated cyclic AMP-independent inhibition of specific mRNA translation.
研究了在饥饿大鼠中重新喂食葡萄糖、蛋白质或脂肪的效果以及注射胰岛素对肝磷酸烯醇式丙酮酸羧激酶（GTP：草酰乙酸羧基裂解酶（转磷酸化），EC 4.1.1.32）活性、肝环磷酸腺苷（cAMP）浓度和血清胰岛素水平的影响。在所有检测条件下，血清胰岛素浓度均大幅升高。然而，只有重新喂食葡萄糖的大鼠随着血清胰岛素的增加，磷酸烯醇式丙酮酸羧激酶活性降低，而分别在重新喂食蛋白质或脂肪后或注射胰岛素后，该酶的活性保持不变或升高。由于在所有条件下，环磷酸腺苷浓度与磷酸烯醇式丙酮酸羧激酶活性之间密切相关，而胰岛素水平与酶活性之间无相关性，因此得出结论：该激素通过降低肝内环磷酸腺苷浓度而非通过假定的不依赖环磷酸腺苷对特定mRNA翻译的抑制来生理调节磷酸烯醇式丙酮酸羧激酶活性。
