guanosine-monophosphate and Pre-Eclampsia

Nitric Oxide (NO) is a potent vascular endothelial cell derived vasorelaxant with important effects on vascular tone. This study was initiated to clarify the role of urinary metabolites of nitric oxide (NOx) during pregnancy. Twenty four normal pregnant women and 12 patients with preeclampsia were studied. Urinary NOx levels were determined with the Greiss reagent and spectrophotometry methods after enzymatic reduction of nitrate to nitrite in the samples. Urinary excretion of nitric oxide (NOx) were elevated in normal pregnant women and decreased in preeclamptic women. A significant correlationship was observed in the urinary excretion of cyclic guanosine monophosphate (cGMP) level in between the normal and preeclamptic puerperial groups (p < 0.05). Positive correlationships were found between urinary excretion of nitrate level and either of fractional excretion of sodium (FENa) (r = 0.702, p < 0.005) or fractional excretion of calcium (FECa) (r = 0.570, p < 0.04) in normal and preeclamptic subjects. Also a positive correlationship was observed between the level of urinary NOx excretion and high density lipoprotein cholesterol (HDL-cholesterol) (r = 0.681, p < 0.005). Our results suggest that nitric oxide may play an important role in the mechanism to modulate circulatory physiology of normal and preeclamptic pregnant women.

Topics: Female; Guanosine Monophosphate; Hemodynamics; Humans; Nitric Oxide; Pre-Eclampsia; Pregnancy; Reference Values

To evaluate the platelet antioxidant enzyme activity and platelet activation degree in patients with pregnancy induced hypertension (PIH).. A monoclonal antibody specific for alpha-granule membrane protein (GMP-140) of platelet was used to evaluate the platelet (plt) activation degree in 44 cases with PIH and 28 cases of normal pregnant women. Meanwhile, the platelet antioxidant enzyme (superoxide dismutase, SOD; catalase, CAT) activity were determined.. Platelet SOD activity of PIH (22.08 +/- 7.66 U/10(9) plt) was markedly lower than that of the controls (26.67 +/- 7.59 U/10(9)plt, P < 0.01). There was no difference between the CAT activity of PIH and controls (9.26 +/- 4.53 K/10(12) plt, 8.57 +/- 3.69 K/10(12) plt, P > 0.05). The number of GMP-140 molecules on platelet surface and serum levels of PIH (2073 +/- 902 molecules/plt, 4.65 +/- 1.74 molecules/L x 10(-13) were significantly higher than those of the normal pregnant women (1319 +/- 716 molecules/plt, 1.69 +/- 0.78 molecules/L x 10(-12), P < 0.01). Correlation analysis between GMP-140 on platelet surface, GMP-140 in the serum and SOD activity of PIH showed definite negative correlation (r = -0.601, -0.670 respectively, P < 0.05).. The decline of platelet antioxidant enzyme activity (especially SOD) and platelet activation could play an important role in the pathophysiological changes in PIH. The platelet SOD activity and GMP-140 could be new index of platelet hyperactivity.

Topics: Adult; Antibodies, Monoclonal; Catalase; Female; Guanosine Monophosphate; Humans; P-Selectin; Platelet Activation; Pre-Eclampsia; Pregnancy; Superoxide Dismutase

To study the effects of low doses of the hormone atrial natriuretic peptide (ANP) on uteroplacental blood flow in patients with preeclampsia.. Eleven women with preeclampsia were infused intravenously with ANP (10 ng/kg/minute). Uteroplacental blood flow index was measured using dynamic placental scintigraphy with indium-113m. Regional blood flows were assessed by pulsed Doppler ultrasound and expressed as pulsatility index (PI). Hemodynamic measurements and blood sampling for peripheral venous plasma analysis of cyclic guanosine monophosphate (cGMP), an ANP second messenger, were performed before and after 30 minutes of infusion. Nonparametric statistics were used.. The uteroplacental blood flow index increased by 28% (-2 to 58%; mean and 95% confidence interval). The Doppler findings were unaffected. Mean arterial blood pressure decreased from 112 (108-117) to 108 (103-114) mmHg (P < .01). Cyclic GMP increased significantly from 9.2 (6.2-12.3) to 17.4 (12.3-22.6) nmol/L (P < .01). Subjects exhibiting a substantial increase in uteroplacental blood flow index (25% or more) demonstrated a significantly greater cGMP response (P < .01) than those who did not (6% or less increase).. A tendency to an increased uteroplacental blood flow index combined with minor blood pressure reduction after ANP infusion suggest the possibility of uteroplacental vasodilatation.

Topics: Adult; Atrial Natriuretic Factor; Blood Flow Velocity; Blood Pressure; Female; Guanosine Monophosphate; Humans; Indium Radioisotopes; Infusions, Intravenous; Maternal-Fetal Exchange; Placenta; Pre-Eclampsia; Pregnancy; Pulsatile Flow; Radionuclide Imaging; Regional Blood Flow; Ultrasonography, Prenatal; Uterus; Vasodilation