CYCLIC-AMP AND FREE FATTY-ACIDS IN THE LONGER-TERM REGULATION OF PYRUVATE-DEHYDROGENASE KINASE IN RAT SOLEUS MUSCLE
CYCLIC-AMP AND FREE FATTY-ACIDS IN THE LONGER-TERM REGULATION OF PYRUVATE-DEHYDROGENASE KINASE IN RAT SOLEUS MUSCLE
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DOI：
10.1016/0167-4889(92)90137-z
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发表时间：
1992-06-10
期刊：
影响因子：
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通讯作者：
RANDLE, PJ
中科院分区：
文献类型：
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作者：
STACE, PB;FATANIA, HR;RANDLE, PJ
饥饿增加丙酮酸脱氢酶（PDH）激酶活性的提取物新鲜切除大鼠比目鱼肌2.2倍（从0.6分钟-1在喂养大鼠1.31分钟-1在48小时饥饿大鼠）。在进食的大鼠中，在培养基199中培养24小时后活性不变，但在用50 μ M二丁酰cAMP加1 mM正辛酸盐培养24小时后增加2.1倍，单独使用任一种试剂增加1.6-1.7倍。约在培养基199中培养24小时后，70%的由饥饿诱导的PDH激酶增加消失; 50 μ M二丁酰cAMP加1 mM正辛酸盐防止了这种损失。新鲜比目鱼肌中cAMP浓度为1 nmol/g（进食大鼠）和1.6 nmol/g（饥饿大鼠）。培养20-60分钟后，饥饿-进食差异消失，[cAMP]降至0.4 nmol/g。降钙素基因相关肽（CGRP）使大鼠比目鱼肌cAMP增加3倍，在培养24 h内持续增加，但在培养30 min或培养24 h后，用无CGRP的培养液培养60 min即可逆转。它的结论是，文化可能会扭转饥饿对PDH激酶活性的影响，通过降低cAMP和去除循环游离脂肪酸的体内效应;饥饿和CGRP没有检测到的长期影响，在比目鱼肌cAMP系统。
Starvation increased pyruvate dehydrogenase (PDH) kinase activity in extracts of freshly excised rat soleus 2.2-fold (from 0.6 min-1 in fed rats to 1.31 min-1 in 48-h-starved rats). In fed rats, activities were unchanged following 24 h of culture in medium 199, but increased 2.1-fold on 24 h of culture with 50-mu-M dibutyryl cAMP plus 1 mM n-octanoate and 1.6-1.7-fold with either agent alone. Approx. 70% of the increase in PDH kinase induced by starvation was lost following 24 h of culture in medium 199; the loss was prevented by 50-mu-M dibutyryl cAMP plus 1 mM n-octanoate. cAMP concentrations in fresh soleus muscle were 1 nmol/g (fed rats) and 1.6 nmol/g (starved rats). After 20-60 min of culture the fed-starved difference disappeared and [cAMP] fell to 0.4 nmol/g. Calcitonin-gene-related peptide (CGRP) increased cAMP 3-fold; the increase was maintained throughout 24 h of culture, but was readily reversed at 30 min or 24 h of culture by 60-min incubation with CGRP-free medium, Starvation of the rat (48 h) had no effect on the sensitivity of soleus towards the [cAMP]-increasing efffect of CGRP. It is concluded that culture may reverse effects of starvation on PDH kinase activity by lowering cAMP and by removal from the in vivo effects of circulating free fatty acids; and that starvation and CGRP had no detectable long-term effects on the cAMP system in soleus muscle.