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.


METHODS
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 micromol/L cells/h+/-433.51) in comparison with normal pregnant women (V(max)=584.73 micromol/L cells/h+/-422.33). No significant difference was detected in the half-saturation constant (P=0.978).


CONCLUSIONS
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.
Programa de Pós-graduação em Clnica Médica e Ciências da Saúde (Nefrologia), Instituto de Pesquisas Biomédicas/Faculdade de Medicina/Hospital São Lucas, Porto Alegre, Brazil.
Bartira Pinheiro
BP
da Costa
João P
JP
Steibel
Ivan Carlos
IC
Antonello
Jorge Almeida
JA
Guimarães
Carlos E
CE
Poli de Figueiredo
D000328:Adult; D001120:Arginine / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000378:metabolism* / Q000503:physiopathology; D011247:Pregnancy / Q000378:metabolism*
D001120:Arginine