Smolin L A, Laidlaw S A, Kopple J D
Am J Clin Nutr. 1987 Apr;45(4):737-43. doi: 10.1093/ajcn/45.4.737.
The plasma sulfur amino acid status of maintenance hemodialysis (MHD) patients has not previously been comprehensively investigated. We measured plasma sulfur amino acid levels in 24 MHD patients (12 fasted, 12 nonfasted) both before and after a routine 4-h hemodialysis and in 13 normal individuals (seven fasted, six nonfasted). Plasma free cystine, homocystine, cysteine-homocysteine-mixed disulfide (MDS), methionine, and taurine and protein-bound cysteine and homocysteine were measured. In nonfasted patients, plasma homocystine and MDS were not measured. Fasted patients predialysis had elevated plasma free cystine, homocystine, MDS, methionine, and taurine; all of these, except taurine, fell during dialysis. In nonfasted patients, plasma free cystine was elevated. Protein-bound cysteine and homocysteine were elevated predialysis and postdialysis in all patients; protein-bound cysteine fell during dialysis but remained above normal. In MHD patients predialysis, plasma free cystine levels correlated with plasma MDS, protein-bound cysteine, and age. These findings indicate pervasive alterations in plasma sulfur amino acid levels in MHD patients.
维持性血液透析（MHD）患者的血浆含硫氨基酸状态此前尚未得到全面研究。我们测定了24例MHD患者（12例禁食，12例非禁食）在常规4小时血液透析前后以及13名正常个体（7例禁食，6例非禁食）的血浆含硫氨基酸水平。测定了血浆游离胱氨酸、同型半胱氨酸、半胱氨酸 - 同型半胱氨酸混合二硫化物（MDS）、蛋氨酸、牛磺酸以及与蛋白质结合的半胱氨酸和同型半胱氨酸。在非禁食患者中，未测定血浆同型半胱氨酸和MDS。禁食患者透析前血浆游离胱氨酸、同型半胱氨酸、MDS、蛋氨酸和牛磺酸水平升高；除牛磺酸外，所有这些在透析期间均下降。在非禁食患者中，血浆游离胱氨酸升高。所有患者透析前和透析后与蛋白质结合的半胱氨酸和同型半胱氨酸均升高；与蛋白质结合的半胱氨酸在透析期间下降，但仍高于正常水平。在MHD患者透析前，血浆游离胱氨酸水平与血浆MDS、与蛋白质结合的半胱氨酸和年龄相关。这些发现表明MHD患者血浆含硫氨基酸水平普遍存在改变。
