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Characterization of cationic amino acid transport systems in rat erythrocytes: lack of effect of uraemia on L-arginine influx.
Clin Exp Pharmacol Physiol. 2006 Aug; 33(8):702-7.CE

Abstract

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.

Authors+Show Affiliations

Departamento de Farmacologia e Psicobiologia, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16895543

Citation

Brunini, T M C., et al. "Characterization of Cationic Amino Acid Transport Systems in Rat Erythrocytes: Lack of Effect of Uraemia On L-arginine Influx." Clinical and Experimental Pharmacology & Physiology, vol. 33, no. 8, 2006, pp. 702-7.
Brunini TM, Yaqoob MM, Roberts NB, et al. Characterization of cationic amino acid transport systems in rat erythrocytes: lack of effect of uraemia on L-arginine influx. Clin Exp Pharmacol Physiol. 2006;33(8):702-7.
Brunini, T. M., Yaqoob, M. M., Roberts, N. B., Ellory, J. C., Moss, M. B., Siqueira, M. A., Mann, G. E., & Mendes Ribeiro, A. C. (2006). Characterization of cationic amino acid transport systems in rat erythrocytes: lack of effect of uraemia on L-arginine influx. Clinical and Experimental Pharmacology & Physiology, 33(8), 702-7.
Brunini TM, et al. Characterization of Cationic Amino Acid Transport Systems in Rat Erythrocytes: Lack of Effect of Uraemia On L-arginine Influx. Clin Exp Pharmacol Physiol. 2006;33(8):702-7. PubMed PMID: 16895543.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of cationic amino acid transport systems in rat erythrocytes: lack of effect of uraemia on L-arginine influx. AU - Brunini,T M C, AU - Yaqoob,M M, AU - Roberts,N B, AU - Ellory,J C, AU - Moss,M B, AU - Siqueira,M A S, AU - Mann,G E, AU - Mendes Ribeiro,A C, PY - 2006/8/10/pubmed PY - 2007/8/9/medline PY - 2006/8/10/entrez SP - 702 EP - 7 JF - Clinical and experimental pharmacology & physiology JO - Clin Exp Pharmacol Physiol VL - 33 IS - 8 N2 - 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. SN - 0305-1870 UR - https://www.unboundmedicine.com/medline/citation/16895543/Characterization_of_cationic_amino_acid_transport_systems_in_rat_erythrocytes:_lack_of_effect_of_uraemia_on_L_arginine_influx_ L2 - https://doi.org/10.1111/j.1440-1681.2006.04421.x DB - PRIME DP - Unbound Medicine ER -