Amino acid content of erythrocytes in uremia

Abstract

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.

Effect of Hemodialysis on Plasma and Erythrocyte Phenylalanine Levels in End-Stage Kidney Patients

“…Hemodialysis led to a decrease in plasma phenylalanine level without influencing its concentra tion in erythrocytes. Similar observations concerned with the behavior of several other amino acids were reported by Jontofsohn et al [8], They suppose that red blood cells can rapidly replenish their free amino acid content by a direct amino acid uptake from tissues. This explanation is consistent with the experimental data reported by £/-wyn et al [5,6] who found that the amino acid transport across the cell membrane of dog erythrocytes took place during the passage of erythrocytes through the hepatic capillary bed, lasting only a few seconds.…”

Effect of Amino Acid Based Dialysis Solution on Peritoneal Permeability and Prostanoid Generation in Patients Undergoing Continuous Ambulatory Peritoneal Dialysis

“…The sulphosalicylic acid extracts were stored at -7 0°C . Amino acids were analyzed by means o f a conventional single-col umn ion-cxchangc method with a lithium buffer system [25].…”

Erythropoietin Treatment and Amino Acid Metabolism in Hemodialysis Patients

“…In contrast to what was reported, no change in valine and leucine levels was found. Serine and glycine increased slightly and transiently: however, these changes can be accounted for by an increase in the red cell mass, since red blood cells contain higher concentrations of these AA [15]. Interestingly, aspartate, which is mainly contained in the blood cell compartment, did not increase despite the augment in the red blood cell mass.…”