MacLennan P A, Brown R A, Rennie M J
FEBS Lett. 1987 May 4;215(1):187-91. doi: 10.1016/0014-5793(87)80139-4.
During muscle-protein wasting associated with injury and disease the distribution ratio of free glutamine between muscle and blood falls. In pursuing possible consequences of this, we investigated the relationship between the rate of muscle protein synthesis and intramuscular glutamine concentration, manipulated acutely in the isolated perfused rat hindquarter. Increasing perfusate glutamine from 0.67 to 5.0 mM caused a 200% increase in intracellular glutamine and a 66% increase in protein synthesis in the absence of insulin; in the presence of insulin a 30% increase in intramuscular glutamine was accompanied by an 80% increase in protein synthesis. Analysis of variance of the results confirmed the existence of positive relationships between intramuscular glutamine and protein synthesis in the presence or absence of insulin. Control of the size of the intramuscular free pool of glutamine may be important in determining the muscle protein mass.
在与损伤和疾病相关的肌肉蛋白消耗过程中，肌肉与血液中游离谷氨酰胺的分布比例会下降。为探究此现象可能产生的后果，我们在分离灌注的大鼠后肢中急性调控肌肉蛋白合成速率与肌内谷氨酰胺浓度，研究二者之间的关系。在无胰岛素的情况下，将灌注液中的谷氨酰胺浓度从0.67 mM提高至5.0 mM，可使细胞内谷氨酰胺增加200%，蛋白质合成增加66%；在有胰岛素的情况下，肌内谷氨酰胺增加30%会伴随蛋白质合成增加80%。对结果进行方差分析证实，无论有无胰岛素，肌内谷氨酰胺与蛋白质合成之间均存在正相关关系。控制肌内谷氨酰胺游离池的大小可能对确定肌肉蛋白量很重要。
