Iizawa H
First Department of Surgery, Yamagata University, School of Medicine, Japan.
Nihon Geka Gakkai Zasshi. 1991 Aug;92(8):964-73.
Metabolism of branched chain amino acids (BCAA) after partial hepatectomy was investigated. Total amino acids of the plasma in the rats undergone 70% partial hepatectomy increased significantly as compared with those of control animals. This increase was due to an increase of sum of all amino acids other than BCAA, whereas total amount of BCAA was unaffected. Both BCAA aminotransferase (BCAA-AT) and branched chain ketoacid dehydrogenase (BCKA-DH), the rate limiting enzymes in BCAA metabolism, increased in mitochondria of the liver and BCAA-AT increased in skeletal muscle homogenate. These increases of both enzymes might reduce the concentration of BCAA relatively. Mitochondrial respiration such as state 3 respiration, respiratory control index (RCI) and ATP synthesis in mitochondria of regenerating liver increased remarkably, when not only succinate but also alpha-ketoisocaproic acid was used as a substrate. ATP synthesis, however, was much higher and mitochondrial respiration was more coupled when alpha-ketoisocaproic acid was used as a substrate. These results suggest that BCAA metabolism was activated after partial hepatectomy and BCAA might serve as an appropriate substrate for regenerating liver.
研究了部分肝切除术后支链氨基酸（BCAA）的代谢情况。与对照动物相比，接受70%部分肝切除的大鼠血浆总氨基酸显著增加。这种增加是由于除BCAA外所有氨基酸总和的增加，而BCAA的总量未受影响。BCAA代谢的限速酶，即BCAA转氨酶（BCAA-AT）和支链酮酸脱氢酶（BCKA-DH），在肝脏线粒体中增加，且BCAA-AT在骨骼肌匀浆中增加。这两种酶的增加可能会相对降低BCAA的浓度。当不仅使用琥珀酸而且使用α-酮异己酸作为底物时，再生肝线粒体中的线粒体呼吸，如状态3呼吸、呼吸控制指数（RCI）和ATP合成显著增加。然而，当使用α-酮异己酸作为底物时，ATP合成更高，线粒体呼吸更耦合。这些结果表明，部分肝切除术后BCAA代谢被激活，且BCAA可能是再生肝的合适底物。
