Jones M R, Kopple J D
Am J Clin Nutr. 1978 Sep;31(9):1660-4. doi: 10.1093/ajcn/31.9.1660.
Valine metabolism was investigated in five normal and three nondialyzed chronically uremic subjects eating 40 +/- SEM 1 and 53 (range 40 to 80) protein diets respectively, in a metabolic research unit. Subjects were injected iv with a tracer dose of L-valine-1-14C while they fasted, and specific activity of plasma valine-14C and expiration of 14CO2 were monitored for two hours. Plasma valine was significantly lower in the uremic patients than in the normal subjects (P less than 0.05). In the uremic patients, specific activity of plasma valine fell less rapidly and remained higher, and expiration of 14CO2 was not different from normal subjects. A two-pool model for valine metabolism was derived which indicated that in uremic patients there was a significant decrease in both valine pools and in the rate of irreversible loss, i.e., valine incorporated into larger molecules, degraded, or excreted. Valine degradation was estimated to be decreased in the uremic patients.
在一个代谢研究室中，对5名正常受试者和3名未接受透析的慢性尿毒症受试者的缬氨酸代谢进行了研究，这些受试者分别食用40±标准误1克和53克（范围为40至80克）蛋白质饮食。在禁食状态下，给受试者静脉注射示踪剂量的L-缬氨酸-1-¹⁴C，并监测血浆缬氨酸-¹⁴C的比活性和¹⁴CO₂的呼出情况，持续两小时。尿毒症患者的血浆缬氨酸水平显著低于正常受试者（P<0.05）。在尿毒症患者中，血浆缬氨酸的比活性下降较慢且保持较高水平，¹⁴CO₂的呼出与正常受试者无差异。得出了一个缬氨酸代谢的双池模型，该模型表明，在尿毒症患者中，两个缬氨酸池以及不可逆损失的速率，即缬氨酸掺入大分子、降解或排泄的速率，均显著降低。据估计，尿毒症患者的缬氨酸降解减少。
