Spydevold O
Acta Physiol Scand. 1976 Jul;97(3):273-80. doi: 10.1111/j.1748-1716.1976.tb10264.x.
The formation of alanine, glutamate, and aspartate from muscle was studied in the isolated perfused hindquarter of rats fasted for 48 h. Tracer doses of (14C) compounds with high specific activity were tested as precursors for the amino acids. Total amounts and radioactivities of the tested amino acids were determined. Alanine was produced more efficiently than glutamate and aspartate even if no exogenous substrate was offered. (14C) Pyruvate was most efficient as precursor of labeled alanine. However, labeled leucine, propionic acid, valine and fumaric acid also produced labeled alanine efficiently. The efficiency as precursor for labeled alanine seemed to be related to the ability to label intermediates in the citric acid cycle in the perfused muscle. From the relation between the ability to label alanine in the perfusion medium and lactate and succinate in the muscle it is suggested that pyruvate may be produced intramitochondrially and is efficiently transaminated to alanine in this compartment.
在禁食48小时的大鼠离体灌注后肢中，研究了肌肉中丙氨酸、谷氨酸和天冬氨酸的生成。测试了具有高比活性的示踪剂量的（14C）化合物作为氨基酸的前体。测定了受试氨基酸的总量和放射性。即使不提供外源底物，丙氨酸的生成效率也高于谷氨酸和天冬氨酸。（14C）丙酮酸作为标记丙氨酸的前体效率最高。然而，标记的亮氨酸、丙酸、缬氨酸和富马酸也能有效地生成标记的丙氨酸。作为标记丙氨酸前体的效率似乎与标记灌注肌肉中柠檬酸循环中间产物的能力有关。根据灌注液中标记丙氨酸的能力与肌肉中乳酸和琥珀酸的关系，提示丙酮酸可能在线粒体内产生，并在该隔室中有效地转氨生成丙氨酸。
