The inactivation of phosphorylase and activation of glycogen synthase in the adipose tissue.
The inactivation of phosphorylase and activation of glycogen synthase in the adipose tissue.
复制标题
脂肪组织中磷酸化酶的失活和糖原合酶的激活。
DOI：
10.1111/j.1432-1033.1980.tb04789.x
复制
发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Hers,HG
中科院分区：
文献类型：
--
作者：
Sobrino,F;Hers,HG
已经证实，在长时间禁食后重新进食时，大鼠在脂肪组织中积累的糖原浓度可以达到非禁食动物的100倍。在精炼动物的脂肪组织中，研究了糖原磷酸化酶和糖原合成酶两种形式的相互转化，这种方法使得在几乎不受磷酸化酶干扰的情况下测定磷酸化酶成为可能。在Sephadex G-25过滤的提取物中，糖原磷酸化酶最初主要以活性形式存在，在25°C孵育滤液后20至60分钟内变得不活跃；在葡萄糖、咖啡因或葡萄糖6-磷酸存在时，这种失活较快，而在EDTA或无机磷存在时，这种失活速度较慢。在同一滤液中，糖原合成酶最初主要以非活性形式存在，并在潜伏期后被激活。所有有利于磷酸化酶失活的药剂均能缩短这一潜伏期，而延缓该酶失活的药剂可延长这一潜伏期。肌肉磷酸酶对糖原合成酶的激活也有抑制作用。所有这些数据都与磷酸化酶是脂肪组织中合成酶磷酸酶抑制剂的假设一致。在分离的脂肪垫中添加葡萄糖或胰岛素会导致磷酸化酶失活，而糖原合成酶在短暂的潜伏期后激活。甘露糖而不是果糖具有与葡萄糖相似的效果。在葡萄糖+胰岛素或果糖+胰岛素存在的情况下，组织中葡萄糖6-磷酸的浓度大致相同，尽管第一种情况下糖原的合成和合成酶的激活比第二种情况下要大得多。给麻醉大鼠注射葡萄糖和胰岛素后，附睾体脂肪体内的磷酸化酶和糖原合成酶依次失活和激活。
It has been confirmed that, upon refeeding after a prolonged fast, rats accumulate glycogen in their adipose tissue at a concentration which can reach 100‐fold that of non‐fasted animals. The inter‐conversion of the two forms of glycogen phosphorylase and glycogen synthase has been investigated in the adipose tissue of refed animals with a methodology which makes it possible to measure phosphorylaseawith little or no interference of phosphorylaseb. In an extract filtered on Sephadex G‐25, glycogen phosphorylase was initially predominantly in the activeaform and became inactive within 20 to 60 min upon incubation of the filtrate at 25°C; this inactivation was faster in the presence of glucose, caffeine or glucose 6‐phosphate and was retarded in the presence of EDTA or inorganic phosphate. In the same filtrate, glycogen synthase was initially predominantly in the inactivebform and became activated after a latency period. This latency period was shortened by all agents which favoured the inactivation of phosphorylase and was prolonged by the agents which retarded the same inactivation. The activation of glycogen synthase was also inhibited by muscle phosphorylasea. All these data are in agreement with the hypothesis that phosphorylaseais an inhibitor of synthase phosphatase in the adipose tissue.The addition of glucose or insulin to isolated fat pads caused an inactivation of phosphorylase; an activation of glycogen synthase occurred after a short latency. Mannose but not fructose had an effect similar to that of glucose. The concentration of glucose 6‐phosphate in the tissue was about equally increased by incubation in the presence of glucose plus insulin or fructose plus insulin although the synthesis of glycogen and synthase activation were much greater in the first condition than in the second.The administration of glucose and insulin to anaesthetized rats caused a sequential inactivation of phosphorylase and activation of glycogen synthase in the epididymal fatin vivo.