Persistence of the effect of insulin on pyruvate dehydrogenase activity in rat white and brown adipose tissue during the preparation and subsequent incubation of mitochondria.
Persistence of the effect of insulin on pyruvate dehydrogenase activity in rat white and brown adipose tissue during the preparation and subsequent incubation of mitochondria.
复制标题
在线粒体的制备和随后的孵育过程中，胰岛素对大鼠白色和棕色脂肪组织中丙酮酸脱氢酶活性的持续影响。
DOI：
10.1042/bj2170441
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
S. Marshall
中科院分区：
文献类型：
--
作者：
R. Denton;J. G. Mccormack;S. Marshall
大鼠附睾脂肪组织中丙酮酸脱氢酶的活性非磷酸化形式的量的增加，作为与胰岛素孵育的结果，不仅在线粒体的制备过程中持续存在，而且在随后的呼吸底物存在下的偶联线粒体孵育过程中也持续存在。如果在存在或不存在附加质膜的情况下将激素直接添加到线粒体，则未发现对胰岛素的影响。几种可能的调节剂的丙酮酸脱氢酶激酶（ATP，ADP，NADH，NAD+，乙酰辅酶A，辅酶A和钾）的浓度进行了测量，在大鼠附睾脂肪组织线粒体培养的条件下，在丙酮酸脱氢酶活性的差异持续作为胰岛素作用的结果。没有发现改变，这表明抑制激酶不是胰岛素激活丙酮酸脱氢酶的主要手段。线粒体内的镁浓度也不受影响。肩胛间棕色脂肪组织中丙酮酸脱氢酶活性的差异与冷适应大鼠血浆胰岛素浓度的操纵也被证明在制备过程中持续存在，随后孵育的线粒体在GDP的存在或不存在。有人指出，胰岛素对丙酮酸脱氢酶在孵育的线粒体的影响的持久性将促进认识的激素的这种行动的机制。有证据表明，胰岛素的短期作用涉及丙酮酸脱氢酶磷酸酶活性的增加，而不是抑制丙酮酸脱氢酶激酶进行了讨论。
Increases in the amount of the active non-phosphorylated form of pyruvate dehydrogenase in rat epididymal adipose tissue, as a result of incubation with insulin, persist not only during the preparation of mitochondria but also during subsequent incubation of coupled mitochondria in the presence of respiratory substrates. No effect on insulin was found if the hormone was added directly to mitochondria in the presence or absence of added plasma membranes. Concentrations of several possible regulators of pyruvate dehydrogenase kinase (ATP, ADP, NADH, NAD+, acetyl-CoA, CoA and potassium) were measured in rat epididymal-adipose-tissue mitochondria incubated under conditions where differences in pyruvate dehydrogenase activity persist as a result of insulin action. No alterations were found, and it is suggested that inhibition of the kinase is not the principal means by which insulin activates pyruvate dehydrogenase. The intramitochondrial concentration of magnesium was also unaffected. Differences in pyruvate dehydrogenase activity in interscapular brown adipose tissue associated with manipulation of plasma insulin concentrations of cold-adapted rats were also shown to persist during the preparation and subsequent incubation of mitochondria in the presence or absence of GDP. It is pointed out that the persistence of the effect of insulin on pyruvate dehydrogenase in incubated mitochondria will facilitate the recognition of the mechanism of this action of the hormone. Evidence that the short-term action of insulin involves an increase in pyruvate dehydrogenase phosphate phosphatase activity rather than inhibition of that of pyruvate dehydrogenase kinase is discussed.