THE REGULATION OF ADIPOSE CELL-METABOLISM
THE REGULATION OF ADIPOSE CELL-METABOLISM
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DOI：
10.1079/pns19820027
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发表时间：
1982-01-01
影响因子：
7
通讯作者：
WALLIS, S
中科院分区：
文献类型：
--
作者：
GALTON, DJ;WALLIS, S
增加了来自组织的能量平衡169的调节。因此，葡萄糖和脂肪酸通过底物循环的活动相互联系，独立于激素控制，这就提供了在进食和禁食状态之间燃料经济性的变化。胰岛素除了调节葡萄糖进入细胞外，还可能对参与葡萄糖代谢的胞内酶的调节产生直接影响(Denton等人)。1977年)。我们的实验室最近一直在研究人类脂肪细胞中丙酮酸激酶的活性(Stansbie等人。1982年)。这种酶的活性很高，似乎受到胰岛素的急性调节(图3)。这可能涉及磷酸化-去磷酸化反应，通过类似于肝脏中的丙酮酸激酶，将高K转化为低K形式(Denton&Halestrap，1979)。如果禁食的受试者被静脉输注葡萄糖(和胰岛素)，30分钟后就有可能检测到丙酮酸激酶的变化。胰岛素对脂肪组织中丙酮酸激酶和其他关键调节酶如己糖激酶和磷酸果糖激酶相互转化的作用机制需要进一步的研究，这可能有助于阐明成年糖尿病患者发生各种胰岛素抵抗状态的原因。
Vol. 41 Regulation of energy balance 169 from the tissue is increased. Thus, glucose and fatty acids are linked reciprocally by the activity of this substrate cycle, independently of hormonal controls, and this provides for the changes in fuel economy between fed and fasted states. Insulin, apart from regulating the entry of glucose into cells, may also have direct effects on the regulation of intracellular enzymes involved in glucose metabolism (Denton et al. 1977). Our laboratory has been recently studying the activity of pyruvate kinase in human adipocytes (Stansbie et al. 1982). This enzyme is present in high activities and appears to be under acute regulation by insulin (Fig. 3). This may involve phosphorylation-dephosphorylation reactions converting a high K, to a low K, form of the enzyme by analogy with pyruvate kinase in the liver (Denton & Halestrap, 1979). If fasted human subjects are given intravenous infusions of glucose (and insulin) it is possible to detect changes in the K,,, of pyruvate kinase after 30 min. The mechanism of insulin action on the interconversion of pyruvate kinase, and other key regulatory enzymes such as hexokinase and phosphofructokinase in adipose tissue requires further study and may help to clarify the cause of various insulin-resistant states occurring in adult diabetics.