RADIOISOTOPIC ASSAYS OF COASH AND CARNITINE AND THEIR ACETYLATED FORMS IN HUMAN SKELETAL-MUSCLE
RADIOISOTOPIC ASSAYS OF COASH AND CARNITINE AND THEIR ACETYLATED FORMS IN HUMAN SKELETAL-MUSCLE
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DOI：
10.1016/0003-2697(90)90292-h
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发表时间：
1990-03-01
影响因子：
2.9
通讯作者：
HULTMAN, E
中科院分区：
文献类型：
--
作者：
CEDERBLAD, G;CARLIN, JI;HULTMAN, E
用于测定乙酰辅酶A、Coash和乙酰肉碱的放射性同位素分析方法已被改进，以适用于可通过针刺活检获得的人体肌肉组织的数量。在这三种方法共有的最后一步，乙酰辅酶A与[14C]草酰乙酸酯在柠檬酸合成酶的作用下缩合得到[14C]-柠檬酸酯。为了测定Coash，Coash在磷酸转乙酰基酶的催化下与乙酰磷酸反应生成乙酰辅酶A。在乙酰肉碱的测定中，乙酰肉碱在肉碱乙酰转移酶的催化下与Coash反应生成乙酰辅酶A。还描述了在乙酰肉碱测定中加入新的简单步骤以及影响所有三种方法可靠性的条件。人腹直肌的乙酰肉碱和游离肉碱水平为3.0±-。1.5(SD)和13.5.+-。分别为4.0微克/克干重。乙酰辅酶A和Coash的值大约低500倍，6.7+-。1.8和21。+-。8.9nmol/g干重。在肌肉剧烈运动时的股外侧肌活检组织中，乙酰肉碱(Y)和短链乙酰肉碱(X)之间存在很强的相关性，y=1.0x+0.50；r=0.976。
Radioisotopic assays for the determination of acetyl-CoA, CoASH, and acetylcarnitine have been modified for application to the amount of human muscle tissue that can be obtained by needle biopsy. In the last step common to all three methods, acetyl-CoA is condensed with [14C]oxaloacetate by citrate synthase to give [14C]-citrate. For determination of CoASH, CoASH is reacted with acetylphosphate in a reaction catalyzed by phosphotransacetylase to yield acetyl-CoA. In the assay for acetylcarnitine, acetylcarnitine is reacted with CoASH in a reaction catalyzed by carnitine acetyltransferase to form acetyl-CoA. Inclusion of new simple steps in the acetylcarnitine assay and conditions affecting the reliability of all three methods are also described. Acetylcarnitine and free carnitine levels in human rectus abdominis muscle were 3.0 .+-. 1.5 (SD) and 13.5 .+-. 4.0 .mu.mol/g dry wt, respectively. Values for acetyl-CoA and CoASH were about 500-fold lower, 6.7 .+-. 1.8 and 21 .+-. 8.9 nmol/g dry wt, respectively. A strong correlation between acetylcarnitine (y) and short-chain acylcarnitine (x), determined as the difference between total and free carnitine, was found in biopsies from the vastus lateralis msucle obtained during intense muscular effort, y = 1.0x+0.5; r=0.976.