Plasma L-arginine is markedly reduced in pregnant women affected by preeclampsia.

The objective of this study was to determine the concentration of free L-amino acids and in particular of L-arginine in the plasma of pregnant women affected by preeclampsia compared to healthy pregnant women in order to know if an alteration in the concentrations of these amino acids occurs in preeclamspia. Twelve pregnant women affected by preeclampsia and twelve pregnant control women, ages 28-35 years old and at the 35-36 weeks of pregnancy were studied. The blood analysis of free amino acids was carried out by using a high performance liquid chromatographic (HPLC) fluorometric method and OPA-NAC as derivatizing agent for the amino acid determination. In the blood of women affected by preeclampsia L-arginine is markedly reduced compared to controls (about five-fold lower, P<0.01). The other amino acids also are significantly reduced, but to lesser extents (about 1.5 times lower, P<0.05). Thus, the determination of L-arginine in the blood of pregnant women could potentially constitute an additional marker for the early diagnosis of preeclampsia.