L-arginine erythrocyte transport in normal pregnant and preeclamptic women

Objective: Uptake Of L-arginine by the cell via amino acid transporter systems is the first step for nitric oxide (NO) production. The current study aimed to assess the total L-arginine uptake in erythrocytes of normal pregnant and preeclamptic women. Study design: Twenty-one normal pregnant and 21 preeclamptic women were studied. To measure total L-arginine uptake in erythrocytes, carbon 14 was used as a. marker and Michaelis-Menten kinetic parameters (V-max and K-m) were evaluated. Results: In preeclamptic women, there was a significant increase (P < .004) in the mean maximal capacity of transport in erythrocytes (V-max = 982.69 mumol/L cells/h +/- 433.51) in comparison with normal pregnant women (V-max = 584.73 mumol/L cells/h +/- 422.33). No significant difference was detected in the half-saturation constant (P = 0.978). Conclusion: The transport kinetics of the NO precursor, L-arginine, is altered in erythrocytes of preeclamptic women. It is possible that abnormal L-arginine uptake may contribute to the pathophysiologic mechanisms of preeclampsia syndrome. (C) 2004 Elsevier Inc. All rights reserved.