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Erythrocyte L-arginine uptake in peritoneal dialysis patients: systems y and y+ L.
Adv Perit Dial. 2005; 21:2-4.AP

Abstract

L-Arginine is the substrate for nitric oxide synthesis and may enter cells by the y+ and y+ L transport systems. Peritoneal membrane characteristics may depend on vascular function and the L-arginine-nitric oxide pathway. In a cross-sectional study, we evaluated erythrocyte L-arginine uptake in stable peritoneal dialysis (PD) patients with various categories of peritoneal transport function. We used 14C as a marker and N-ethyl-maleimide as an inhibitor of the y+ system to measure maximal uptake capacity (Vma in ulmol/L cell/h) and the half-saturation constant (Km in micromol/L) in erythrocytes. The sample consisted of 41 patients (mean age: 50 +/- 17 years; 5 with diabetes; 18 men). Mean dialysate-toplasma creatinine (D/P(Cr)) was 0.62 +/- 0.14. Peritoneal membrane transport was classified as high, high-average, low-average, or low in 10, 11, 11, and 9 patients, respectively. Mean y+ L Vmax, was 208 +/- 111 micromol/L cell/h, 494 +/- 893 micromol/L cell/h, 222 +/- 59 micromol/L cell/h, and 193 +/- 63 umol/L cell/h [p = 0.404, analysis of variance (ANOVA)] for the high, high-average, low-average, and low transporters respectively. Similarly, mean y+ Vmax was 963 +/- 1034 micromol/L cell/h 843 +/- 366 micromol/L cell/h, 639 +/- 254 micromol/L cell/h, and 774 +/- 378 micromol/L cell/h (p = 0.647, ANOVA). As with Vmax, the y+ L Km and y+ Km values were not significantly different between the various peritoneal transport categories. A negative correlation was observed between y+ Vmax and Kt/V (r = -0.393, p = 0.011). Erythrocyte uptake of L-arginine does not vary with peritoneal membrane transport characteristics, but maximal L-arginine uptake capacity is higher in patients with a lower Kt/V.

Authors+Show Affiliations

Programa de Pós-graduação em Medicina e Ciências da Saúde (Nefrologia), Laboratório de Nefrologia, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

16686274

Citation

Figueiredo, Ana E., et al. "Erythrocyte L-arginine Uptake in Peritoneal Dialysis Patients: Systems Y and Y+ L." Advances in Peritoneal Dialysis. Conference On Peritoneal Dialysis, vol. 21, 2005, pp. 2-4.
Figueiredo AE, Almeida PB, Pinheiro da Costa BE, et al. Erythrocyte L-arginine uptake in peritoneal dialysis patients: systems y and y+ L. Adv Perit Dial. 2005;21:2-4.
Figueiredo, A. E., Almeida, P. B., Pinheiro da Costa, B. E., D'Avila, D. O., & Poli de Figueiredo, C. E. (2005). Erythrocyte L-arginine uptake in peritoneal dialysis patients: systems y and y+ L. Advances in Peritoneal Dialysis. Conference On Peritoneal Dialysis, 21, 2-4.
Figueiredo AE, et al. Erythrocyte L-arginine Uptake in Peritoneal Dialysis Patients: Systems Y and Y+ L. Adv Perit Dial. 2005;21:2-4. PubMed PMID: 16686274.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Erythrocyte L-arginine uptake in peritoneal dialysis patients: systems y and y+ L. AU - Figueiredo,Ana E, AU - Almeida,Priscilla B, AU - Pinheiro da Costa,Bartira E, AU - D'Avila,Domingos O, AU - Poli de Figueiredo,Carlos E, PY - 2006/5/12/pubmed PY - 2006/7/1/medline PY - 2006/5/12/entrez SP - 2 EP - 4 JF - Advances in peritoneal dialysis. Conference on Peritoneal Dialysis JO - Adv Perit Dial VL - 21 N2 - L-Arginine is the substrate for nitric oxide synthesis and may enter cells by the y+ and y+ L transport systems. Peritoneal membrane characteristics may depend on vascular function and the L-arginine-nitric oxide pathway. In a cross-sectional study, we evaluated erythrocyte L-arginine uptake in stable peritoneal dialysis (PD) patients with various categories of peritoneal transport function. We used 14C as a marker and N-ethyl-maleimide as an inhibitor of the y+ system to measure maximal uptake capacity (Vma in ulmol/L cell/h) and the half-saturation constant (Km in micromol/L) in erythrocytes. The sample consisted of 41 patients (mean age: 50 +/- 17 years; 5 with diabetes; 18 men). Mean dialysate-toplasma creatinine (D/P(Cr)) was 0.62 +/- 0.14. Peritoneal membrane transport was classified as high, high-average, low-average, or low in 10, 11, 11, and 9 patients, respectively. Mean y+ L Vmax, was 208 +/- 111 micromol/L cell/h, 494 +/- 893 micromol/L cell/h, 222 +/- 59 micromol/L cell/h, and 193 +/- 63 umol/L cell/h [p = 0.404, analysis of variance (ANOVA)] for the high, high-average, low-average, and low transporters respectively. Similarly, mean y+ Vmax was 963 +/- 1034 micromol/L cell/h 843 +/- 366 micromol/L cell/h, 639 +/- 254 micromol/L cell/h, and 774 +/- 378 micromol/L cell/h (p = 0.647, ANOVA). As with Vmax, the y+ L Km and y+ Km values were not significantly different between the various peritoneal transport categories. A negative correlation was observed between y+ Vmax and Kt/V (r = -0.393, p = 0.011). Erythrocyte uptake of L-arginine does not vary with peritoneal membrane transport characteristics, but maximal L-arginine uptake capacity is higher in patients with a lower Kt/V. SN - 1197-8554 UR - https://www.unboundmedicine.com/medline/citation/16686274/Erythrocyte_L_arginine_uptake_in_peritoneal_dialysis_patients:_systems_y_and_y+_L_ DB - PRIME DP - Unbound Medicine ER -