PATHWAY OF GLUTAMATE OXIDATION GY MITOCHONDRIA ISOLATED FROM DIFFERENT TISSUES
PATHWAY OF GLUTAMATE OXIDATION GY MITOCHONDRIA ISOLATED FROM DIFFERENT TISSUES
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DOI：
10.1016/0006-3002(62)91119-8
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发表时间：
1962-01-01
期刊：
影响因子：
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通讯作者：
BORST, P
中科院分区：
文献类型：
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作者：
BORST, P
1.研究了大鼠肝脏、Enrlich腹水细胞、大鼠心脏和鸽胸肌线粒体氧化谷氨酸的途径。2.丙二酸对谷氨酸氧化的平均抑制率：大鼠肝线粒体为70%，腹水细胞线粒体为82%，大鼠心脏肌小体为97%，鸽胸肌肌小体为97%以上。氟化物对鸽子-胸肌-肌小体和亚砷酸盐对大鼠心脏肌小体也几乎完全抑制。3.在大鼠肝、大鼠心脏和腹水细胞线粒体氧化谷氨酸的过程中，[α]-酮戊二酸的积累几乎可以忽略不计，[Delta]O/[Delta][α]-酮戊二酸在几乎所有实验中都大于100。4.分光光度法测得大鼠肝线粒体谷氨酸脱氢酶活性很高，腹水细胞线粒体中谷氨酸脱氢酶活性中等，而大鼠心脏和鸽胸肌肌小体中未见谷氨酸脱氢酶活性。Krebs[Long dash]Cohen错位形成谷氨酸的速率与谷氨酸脱氢酶活性大致平行。5.谷氨酸在没有抑制剂的情况下氧化生成天冬氨酸。用细菌脱羧酶测定，腹水细胞线粒体的平均[Delta]谷氨酸/[Delta]天冬氨酸值分别为1.0和1.1。对于大鼠肝脏、大鼠心脏和鸽子胸肌线粒体。6.在本实验条件下，线粒体谷氨酸氧化的主要途径是谷氨酸-草酰乙酸转氨酶转化为天冬氨酸，然后是位于α-酮戊二酸和草酰乙酸酯之间的Krebs循环部分。在大鼠心脏和鸽子胸肌肌小体中，转氨化途径是谷氨酸快速氧化的唯一途径。
1. The pathway of glutamate oxidation by mitochondria isolated from rat liver, Enrlich ascites cells, rat heart and pigeon-breast muscle has been investigated. 2. The average inhibition of glutamate oxidation by malonate was 70% with rat-liver mitochondria, 82% with ascites-cell mitochondria, 97% with rat-heart sarcosomes and more than 97% with pigeon-breast-muscle sarcosomes. Almost complete inhibition was also found by fluoride with pigeon-breast-muscle sarcosomes and by arsenite with rat-heart sarcosomes. 3. Accumulation of [alpha]-ketoglutarate during the oxidation of glutamate by rat-liver, rat-heart and ascites-cell mitochondria was negligible, the [DELTA] O/[DELTA] [alpha]-ketoglutarate being larger than 100 in nearly all experiments. 4. Glutamic dehydrogenase activity, measured spectro-photometrically, was very high in rat-liver mitochondria and moderate in ascites-cell mitochondria, while no activity could be demonstrated in rat-heart or pigeon-breast-muscle sarcosomes. The rate of glutamate formation by the KREBS[long dash]COHEN dismutation ran roughly parallel to the glutamic dehydrogenase activity. 5. During glutamate oxidation in the absence of inhibitors aspartate was formed. The average [DELTA]glutamate/[DELTA] aspartate value, determined with bacterial decarboxylases, was 1.0 for ascites-cell mitochondria and 1.1. for rat-liver, rat-heart and pigeon-breast-muscle mitochondria. 6. It is concluded that under the experimental conditions used, the predominant pathway for glutamate oxidation in the mitochondria studied is conversion to aspartate by means of glutamate-oxaloacetate transaminase followed by that part of the Krebs-cycle lying between a-ketoglutarate and oxaloacetate. In rat-heart and pigeon-breast-muscle sarcosomes the transamination pathway is the only one available for rapid glutamate oxidation.