Structural changes in erythrocyte membranes in nephropathy

Панасенко, О. М.; Shalina, R.I.; Azizova, O. A.

doi:10.1007/bf00842738

Cited by 4 publications

(4 citation statements)

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“…The changes in both V max and K m for l ‐arginine transport observed in RBC from CRF patients cannot result only from an altered number of functional y + transporters per erythrocyte and could result from uraemic changes in plasma membrane properties. There are several reports of altered erythrocyte lipid composition in uraemia 36,37 . Because a particular lipid bilayer environment is required for activity of membrane proteins, 38 perhaps the alterations present in uraemia affect the activity of system y + .…”

Section: Discussionmentioning

confidence: 99%

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ACTIVATION OF l‐ARGININE TRANSPORT IN UNDIALYSED CHRONIC RENAL FAILURE AND CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS

Brunini

Roberts

Yaqoob

et al. 2006

Clin Exp Pharma Physio

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1. Treatment with haemodialysis and continuous ambulatory peritoneal dialysis (CAPD) presents different pathophysiological profiles and it has been suggested that clinical outcome in chronic renal failure may depend on the mode of dialysis. The transport of L-arginine, a precursor of nitric oxide, into blood cells is increased in uraemic patients on haemodialysis. The present study was designed to investigate L-arginine transport into red blood cells (RBC) in uraemic patients not yet on dialysis and on CAPD therapy. 2. Eleven uraemic patients not yet on dialysis and 17 on CAPD were included in the study. L-Arginine transport into RBC and plasma and RBC amino acid profiles were analysed in these sets of patients. 3. L-Arginine transport via system y(+), but not y(+)L, into RBC, was significantly increased in undialysed uraemic patients (459 +/- 40 micromol/L per cell per h) and CAPD patients (539 +/- 61 micromol/L per cell per h) compared with controls (251 +/- 39 micromol/L per cell per h). High-pressure liquid chromatography measurements demonstrated low levels of plasma L-arginine in uraemic patients both on CAPD (54 +/- 3 micromol/L) and not yet on dialysis (80 +/- 6 micromol/L) compared with control subjects (146 +/- 14 micromol/L). 4. Our findings provide the first evidence that uraemic patients not yet on dialysis and on CAPD present with an activation of L-arginine transport via system y(+) into RBC associated with reduced plasma levels of L-arginine.

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Section: Discussionmentioning

confidence: 99%

“…There are several reports of altered erythrocyte lipid composition in uraemia. 36,37 Because a particular lipid bilayer environment is required for activity of membrane proteins, 38 perhaps the alterations present in uraemia affect the activity of system y + .…”

Section: Discussionmentioning

confidence: 99%

ACTIVATION OF l‐ARGININE TRANSPORT IN UNDIALYSED CHRONIC RENAL FAILURE AND CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS

Brunini

Roberts

Yaqoob

et al. 2006

Clin Exp Pharma Physio

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“…embedded in this membrane. [46][47][48][49] In uraemic rats, there is no report of lipid abnormality in erythrocytes. Finally, uraemia resembles a state of poisoning with circulating toxins and it is possible that to cause the changes observed in the y + transport system from uraemic patients, a severe degree of renal failure, together with prolonged exposure to uraemic toxins, is necessary.…”

Section: Discussionmentioning

confidence: 99%

“…Another explanation for this finding is that the y + transport system observed in rat RBC is not affected by the same stimuli that cause upregulation of the human y + transport system. Plasma membrane of RBC from uraemic patients present an altered lipid composition that could influence the transporters embedded in this membrane 46–49 . In uraemic rats, there is no report of lipid abnormality in erythrocytes.…”

Section: Discussionmentioning

confidence: 99%

CHARACTERIZATION OF CATIONIC AMINO ACID TRANSPORT SYSTEMS IN RAT ERYTHROCYTES: LACK OF EFFECT OF URAEMIA ON l‐ARGININE INFLUX

Brunini

Yaqoob²,

Roberts

et al. 2006

Clin Exp Pharma Physio

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1. Chronic renal failure (CRF) is associated with the abnormal regulation of nitric oxide (NO) synthesis at the systemic level. The transport of L-arginine, upregulated in blood cells from uraemic patients, modulates NO synthesis in this pathological condition. The model of partial nephrectomy in rats is widely accepted as a valid model of uraemia. Because there are no reports of L-arginine transport in blood cells from uraemic rats, the aim of the present study was to investigate L-arginine transport in red blood cells (RBCs) from these rats. 2. The kinetics of L-arginine transport in RBC and plasma and the amino acid profiles of RBC were investigated in control, sham-operated and subtotally nephrectomized rats. 3. L-Arginine transport was mediated via the cationic amino acid transport system y+ and a transport system with kinetics resembling the human system y+L. In control RBC, the apparent Ki for L-leucine inhibition of L-arginine transport via system y+L was 0.16 +/- 0.02 and 4.8 +/- 2 mmol/L in the presence of Li+ and Na+, respectively. 4. The Vmax values for L-arginine transport via system y+L and system y+ were similar in RBC from control sham-operated and uraemic rats. Moreover, L-arginine concentrations in plasma and RBC were not affected by uraemia. 5. The findings of the present study provide the first evidence that L-arginine transport in rat erythrocytes is mediated by two distinct cationic transport systems with characteristics of systems y+ and y+L, which accept neutral amino acids only in the presence of Li+. In contrast with previous studies in uraemic patients, plasma levels and maximal transport rates of L-arginine were not altered in this rat model of CRF.

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Membrane Lipid Changes in the Abnormal Red Cell

Luly¹

1989

The Red Cell Membrane

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Structural changes in erythrocyte membranes in nephropathy

Cited by 4 publications

References 0 publications

ACTIVATION OF l‐ARGININE TRANSPORT IN UNDIALYSED CHRONIC RENAL FAILURE AND CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS

ACTIVATION OF l‐ARGININE TRANSPORT IN UNDIALYSED CHRONIC RENAL FAILURE AND CONTINUOUS AMBULATORY PERITONEAL DIALYSIS PATIENTS

CHARACTERIZATION OF CATIONIC AMINO ACID TRANSPORT SYSTEMS IN RAT ERYTHROCYTES: LACK OF EFFECT OF URAEMIA ON l‐ARGININE INFLUX

Membrane Lipid Changes in the Abnormal Red Cell

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