Erben J, Schück O, Palicka V, Fixa P, Hájková B, Herout V, Stilec B, Zahradník J
I. interní klinika a Ustav klinické biochemie a diagnostiky LF UK a fakultní nemocnice, Hradec Králové.
Cas Lek Cesk. 1994 May 30;133(11):343-5.
Dialyzed patients are chronically in a state of negative nitrogen balance, and amino acids, their building stones, are also significantly affected by dialysis. The purpose of the present investigation was to assess whether they should be supplied, how frequently and for how long and how they are influenced by the usual diet of patients.
The examination was made in a group of 13 patients included in a regular haemodialysis programme. Their mean age was 53.2 +/- 12.4 years, they were dialyzed for an average period of 55 months, maximum 163 months. The patients were dialyzed three times per week for four hours, bicarbonate dialysate was used. The patients' diet was not modified in any way. A total of 52 haemodialysis were examined: losses of alpha-amino nitrogen were monitored as well as changes of serum concentrations of different amino acids. Their mean losses were 119 +/- 54.69 mmol/4 h: this corresponds to 10.5 +/- 4.8 mg amino acids. The dialysis clearance was on average 122.7 +/- 63.2 ml/min. This value did not differ significantly from the dialysis clearance of urea, but it was significantly higher than creatinine clearance (p < 0.05). During dialysis a significant drop (p < 0.001) of the plasma concentration of amino nitrogen occurred, however, the changes of serum concentrations of amino acids differed. A significant drop was recorded in serum concentrations of histamine, lysine, cysteine, methionine, tyrosine, glycine, asparagine, citrullin, glutamine, taurine. Before the beginning of dialysis the values of valine, lysine, threonine, serine, alanine and asparagine were lower than corresponds to the reference interval in healthy subjects.
Changes of serum concentrations of individual amino acids are significantly influenced not only by their losses into the dialysate but also by their shift from cells into the extracellular fluid and by resorption from the digestive tract during protein intake in the course of dialysis. An adequate supply of high quality protein can compensate for these losses. Investigation of serum concentration of individual amino acids does not record their kinetic changes but can give an idea on the effectiveness of the dietary regime.
透析患者长期处于负氮平衡状态，构成蛋白质的氨基酸也受到透析的显著影响。本研究的目的是评估是否应该补充氨基酸、补充的频率和时长，以及它们如何受到患者日常饮食的影响。
对纳入常规血液透析项目的13名患者进行了检查。他们的平均年龄为53.2±12.4岁，平均透析时间为55个月，最长163个月。患者每周透析3次，每次4小时，使用碳酸氢盐透析液。患者的饮食未作任何调整。共检查了52次血液透析：监测了α-氨基氮的损失以及不同氨基酸血清浓度的变化。其平均损失为119±54.69 mmol/4小时，相当于10.5±4.8毫克氨基酸。透析清除率平均为122.7±63.2毫升/分钟。该值与尿素的透析清除率无显著差异，但显著高于肌酐清除率（p<0.05）。透析期间，氨基氮的血浆浓度显著下降（p<0.001），然而，氨基酸血清浓度的变化各不相同。组胺、赖氨酸、半胱氨酸、蛋氨酸、酪氨酸、甘氨酸、天冬酰胺、瓜氨酸、谷氨酰胺、牛磺酸的血清浓度显著下降。在透析开始前，缬氨酸、赖氨酸、苏氨酸、丝氨酸、丙氨酸和天冬酰胺的值低于健康受试者的参考区间。
个体氨基酸血清浓度的变化不仅受到其向透析液中损失的显著影响，还受到其从细胞向细胞外液转移以及透析过程中蛋白质摄入时从消化道吸收的影响。充足的优质蛋白质供应可以弥补这些损失。对个体氨基酸血清浓度的研究并未记录其动力学变化，但可以了解饮食方案的有效性。
