Jontofsohn R, Trivisas G, Katz N, Kluthe R
Am J Clin Nutr. 1978 Oct;31(10):1956-60. doi: 10.1093/ajcn/31.10.1956.
The amino acid content of plasma and erythrocytes in patients with severe renal failure (serum creatinine less than 8 mg/100 ml) treated with selective low-protein diets, in patients on regular hemodialysis, and in a control group of healthy subjects were studied. Most amino acids in erythrocytes of the patients showed the same changes as in plasma with the exception of histidine, serine, and alanine. In spite of low histidine plasma levels, the erythrocytes level is increased as compared with healthy controls. In uremic patients the plasma serine was constantly reduced whereas the serine content of the erythrocytes did not differ from healthy controls. Alanine concentrations in the erythrocytes of uremic patients were increased in spite of normal alanine plasma levels. This finding may be due to the increased glycolytic ratio of red cells from uremic subjects delivering more pyruvate for transmination to alanine. In the control group the cysteine content of erythrocytes was decreased with a gradient between plasma and erythrocytes of 3.5:1. The same gradient could be observed in uremic patients in spite of the elevation in their plasma cysteine levels by a factor of 2.7 compared with controls. The low cysteine levels in erythrocytes may be due to loss of cysteine for glutathione synthesis in red cells. High glutathione levels in the erythrocytes of uremic patients support this hypothesis.
研究了采用选择性低蛋白饮食治疗的重度肾衰竭患者（血清肌酐低于8mg/100ml）、接受定期血液透析的患者以及健康受试者对照组的血浆和红细胞中的氨基酸含量。除组氨酸、丝氨酸和丙氨酸外，患者红细胞中的大多数氨基酸与血浆中的变化相同。尽管血浆组氨酸水平较低，但与健康对照组相比，红细胞水平有所升高。在尿毒症患者中，血浆丝氨酸持续降低，而红细胞中的丝氨酸含量与健康对照组无差异。尽管尿毒症患者血浆丙氨酸水平正常，但红细胞中的丙氨酸浓度却升高了。这一发现可能是由于尿毒症患者红细胞的糖酵解比率增加，从而产生更多的丙酮酸用于转氨生成丙氨酸。在对照组中，红细胞中的半胱氨酸含量降低，血浆与红细胞之间的梯度为3.5:1。尽管尿毒症患者的血浆半胱氨酸水平比对照组升高了2.7倍，但在他们身上也观察到了相同的梯度。红细胞中半胱氨酸水平较低可能是由于红细胞中用于合成谷胱甘肽的半胱氨酸流失。尿毒症患者红细胞中高谷胱甘肽水平支持这一假说。
