胰高血糖素和肾上腺素对大鼠肝脏支链2-氧代酸脱氢酶的体内激活作用。
Activation of rat liver branched-chain 2-oxo acid dehydrogenase in vivo by glucagon and adrenaline.
作者信息
Block K P, Heywood B W, Buse M G, Harper A E
出版信息
Biochem J. 1985 Dec 1;232(2):593-7. doi: 10.1042/bj2320593.
The activity of liver branched-chain 2-oxo acid dehydrogenase complex was measured in rats fed on low-protein diets and given adrenaline, glucagon, insulin or dibutyryl cyclic AMP in vivo. Administration of glucagon or adrenaline (200 micrograms/100 g body wt.) resulted in a 4-fold increase in the percentage of active complex. As with glucagon and adrenaline, treatment of rats with cyclic AMP (5 mg/100 g body wt.) resulted in marked activation of branched-chain 2-oxo acid dehydrogenase. Insulin administration (1 unit/100 g body wt.) also resulted in activation of enzyme; however, these effects were less than those observed with glucagon and adrenaline. In contrast with the results obtained with low-protein-fed rats, administration of adrenaline (200 micrograms/100 g body wt.) to rats fed with an adequate amount of protein resulted in only a modest (14%) increase in the activity of the complex. The extent to which these hormones activate branched-chain 2-oxo acid dehydrogenase appears to be correlated with their ability to stimulate amino acid uptake into liver.
在以低蛋白饮食喂养并在体内给予肾上腺素、胰高血糖素、胰岛素或二丁酰环磷腺苷（dibutyryl cyclic AMP）的大鼠中，测定了肝脏支链2-氧代酸脱氢酶复合体的活性。给予胰高血糖素或肾上腺素（200微克/100克体重）导致活性复合体的百分比增加了4倍。与胰高血糖素和肾上腺素一样，用环磷腺苷（5毫克/100克体重）处理大鼠会导致支链2-氧代酸脱氢酶显著激活。给予胰岛素（1单位/100克体重）也会导致该酶激活；然而，这些作用小于用胰高血糖素和肾上腺素观察到的作用。与用低蛋白饮食喂养的大鼠所获得的结果相反，给摄入适量蛋白质的大鼠注射肾上腺素（200微克/100克体重）只会使复合体的活性适度增加（14%）。这些激素激活支链2-氧代酸脱氢酶的程度似乎与其刺激氨基酸摄取到肝脏中的能力相关。
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