Plasma- and urine concentrations of nitrite/nitrate and cyclic Guanosinemonophosphate in intrauterine growth restricted and preeclamptic pregnancies.

Abstract

BACKGROUND:

The Nitric Oxide (NO) system plays an important role in the establishment and maintenance of the feto-placental circulation. Research on the pathogenesis of preeclampsia in several studies has established the involvement of the NO-system in preeclampsia and fetal intrauterine growth restriction (IUGR). In the presented study we analyzed the urine and plasma concentrations of nitrite/nitrate, the stable endproducts of NO and its second messenger, cyclic Guanosinemonophosphate (cGMP) in normal, preeclamptic and IUGR pregnancies.

PATIENTS AND METHODS:

In total 76 patients were investigated in a prospective study for repeated determination of plasma and urinary levels of nitrate/nitrite and cGMP: 49 patients with a normal course of pregnancy, 14 patients with fetal IUGR and 13 patients with preeclampsia were included into the study. Plasma and urine Nitrite/Nitrate-concentrations were determined using a Colorimetric Assay (Cayman Inc., USA), concentrations of the second messenger cGMP in plasma and urinary samples were determined with a J(125)-Radio-Immuno-Assay (ibl Inc., Germany). The Stat View Program (Abacus Concepts, Inc., Berkeley, CA, 1992-1998) was used for statistical analysis, a P value <0.05 was considered significant.

RESULTS:

Analyzing the data with the Kruskall-Wallis test a significance was reached for Plasma Nitrite/Nitrate (P=0.0236), plasma cGMP (P=0.004) and urinary nitrite/nitrate (P=0.032). No significance was seen for urinary cGMP (P=0.656). Comparing normal and preeclamptic and normal and IUGR pregnancies the following significant differences were seen (Mann-Whitney U test): In preeclamptic pregnancies urine nitrite/nitrate concentration was significantly lower compared to normal pregnancies (P=0.009) No significant difference between normal and preeclamptic pregnancies for plasma nitrite/nitrate (P=0.819) and plasma-cGMP (P=0.072) could be observed. In IUGR pregnancies plasma nitrite/nitrate and the plasma-cGMP concentrations were both significantly lower compared to normal pregnancies (P=0.0077 and 0.0066) in IUGR-pregnancies. No significance was reached when analyzing urine-Nitrite/Nitrate (P=0.7).

CONCLUSION:

Whereas in preeclampsia a reduced urinary nitrite/nitrate was analyzed, IUGR pregnancies showed reduced plasma nitrite/nitrate and cGMP. A reduced release of NO into the maternal circulation might lead to the presented findings and be involved in the pathogenesis of preeclampsia and fetal IUGR.

• Authors: Barbara Schiessl, Christian Strasburger, Martin Bidlingmaier, Ioannis Mylonas, Udo Jeschke, Franz Kainer, Klaus Friese
• Journal: Archives of gynecology and obstetrics (Arch Gynecol Obstet) Vol. 274 Issue 3 Pg. 150-4 (Jun 2006) ISSN: 0932-0067 [Print] Germany
• PMID: 16532320 (Publication Type: Journal Article)

Chemical References

• Nitrates
• Nitrites
• Nitric Oxide
• Cyclic GMP

Topics

• Birth Weight
• Cyclic GMP (blood, metabolism, urine)
• Female
• Fetal Growth Retardation (metabolism)
• Humans
• Infant, Newborn
• Nitrates (blood, metabolism, urine)
• Nitric Oxide (metabolism)
• Nitrites (blood, metabolism, urine)
• Pre-Eclampsia (metabolism)
• Pregnancy
• Pregnancy Outcome
• Prospective Studies