Glutathione peroxidase levels throughout normal pregnancy and in pre-eclampsia.
OBJECTIVE
Evidence suggests that hemoglobin, in addition to its function as a carrier of oxygen, also serves to transport nitric oxide, as S-nitroso cysteine, from the lungs to the peripheral circulation, where it can be released. Glutathione peroxidase, besides being an important antioxidant, is known to catalyze the release of nitric oxide from smaller carrier molecules, and may play a role in the distribution of nitric oxide throughout the body. In light of these findings, we sought to determine whether glutathione peroxidase levels differed throughout gestation, and specifically between pre-eclamptic and normal women.


METHODS
A nested case-control study of women receiving routine prenatal care was conducted. Pre-eclampsia was defined by a blood pressure of at least 140 mmHg systolic and/or 90 mmHg diastolic as well as proteinuria > 300 mg/24 h or > 2+ by dipstick, both occurring on two occasions at least 6 h apart. Blood was collected in heparinized tubes and was then centrifuged in a clinical centrifuge for 10 min. Plasma was frozen promptly at -80 degrees C for later enzyme-linked immunosorbent assay (ELISA), with which plasma glutathione peroxidase was determined.


RESULTS
The maternal demographics of the pre-eclamptic and non-pre-eclamptic study groups did not significantly vary with respect to mean maternal age, gravidity, parity and gestational age at the time of delivery. The median maternal ages were 33 and 34 years, and the median gestational ages at the time of birth were 37.5 and 38.1 weeks, respectively. In evaluating the glutathione peroxidase levels of all patients across the three trimesters, we found that there was essentially no difference in mean levels (83.7, 81.0 and 89.5 ng/ml, respectively). There was no difference between the pre-eclamptic and non-pre-eclamptic patients, again stratified by trimester. A linear regression analysis indicated that the plasma glutathione peroxidase concentration did not correlate with gestational age or the presence of pre-eclampsia.


CONCLUSIONS
Plasma glutathione peroxidase expression is similar across all trimesters. There is no change in the glutathione peroxidase levels in pre-eclamptic patients.
Funai
E F
EF
Section of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Yale University School of Medicine, New Haven, Connecticut 06520-8063, USA.
MacKenzie
A
A
Kadner
S S
SS
Roque
H
H
Lee
M J
MJ
Kuczynski
E
E
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000201:enzymology / Q000378:metabolism*; D011247:Pregnancy / Q000378:metabolism*; D011264:Pregnancy Trimesters; D011446:Prospective Studies
D005979:Glutathione Peroxidase