Kopple J D, Swendseid M E
J Nutr. 1981 Jun;111(6):931-42. doi: 10.1093/jn/111.6.931.
This study assessed whether changes in plasma histidine or nitrogen balance could indicate the dietary histidine requirement in short-term feeding studies. Five normal and two chronically uremic men were fed diets varying in histidine content in a metabolic research unit. Subjects received amino acid diets for 71 +/- 12 (SD) days during which time the histidine intake was varied between 60 and 2,800 mg/day at 8.0 +/- 0.5 day intervals. The results indicated that both postabsorptive plasma histidine and urinary histidine correlated with the dietary histidine intake. However, in individual patients the response curve of plasma histidine to the dietary histidine intake did not demonstrate a consistent breakpoint which could be used to indicate the dietary histidine requirement. Rather, the histidine intake above which the plasma levels increased rapidly seemed to be influenced by the previous dietary histidine. Urinary histidine excretion also correlated with plasma histidine. N tau-methylhistidine was increased in plasma and reduced in urine of the uremic patients as compared to normal subjects. Nitrogen balances were less positive with histidine intakes of 2 mg/kg/day or lower. These data support the finding that histidine is an essential amino acid in normal and chronically uremic man. However, clinical and metabolic studies of greater duration may be necessary to determine the daily histidine requirement.
本研究评估了在短期喂养研究中，血浆组氨酸或氮平衡的变化是否能够表明饮食中组氨酸的需求量。在一个代谢研究单元中，给5名正常男性和2名慢性尿毒症男性喂食组氨酸含量不同的饮食。受试者接受氨基酸饮食71±12（标准差）天，在此期间，组氨酸摄入量以8.0±0.5天为间隔，在60至2800毫克/天之间变化。结果表明，吸收后血浆组氨酸和尿组氨酸均与饮食中组氨酸摄入量相关。然而，在个体患者中，血浆组氨酸对饮食中组氨酸摄入量的反应曲线并未显示出可用于表明饮食中组氨酸需求量的一致转折点。相反，血浆水平迅速升高时的组氨酸摄入量似乎受先前饮食中组氨酸的影响。尿组氨酸排泄也与血浆组氨酸相关。与正常受试者相比，尿毒症患者血浆中的N-τ-甲基组氨酸增加，尿液中的N-τ-甲基组氨酸减少。当组氨酸摄入量为2毫克/千克/天或更低时，氮平衡的正向性降低。这些数据支持了组氨酸是正常和慢性尿毒症男性必需氨基酸这一发现。然而，可能需要进行更长时间的临床和代谢研究来确定每日组氨酸需求量。
