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Updated: Aug 8, 2026
Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Detection and measurement of urinary 2-hydroxyestradiol 17-sulfate, a potential placental antioxidant during
K Takanashi1, T Honma, T Kashiwagi
1Hokkaido College of Pharmacy, 7-1, Katsuraoka-cho, Otaru 047-0264, Japan.
Background:
Preeclampsia is associated with a quantitative imbalance between lipid peroxide and an antioxidant coproduced in the placenta. To investigate our hypothesis that 2-hydroxyestradiol 17-sulfate (2-OH-ES) is the placental antioxidant during pregnancy, we developed an assay for 2-OH-ES in urine and studied samples from women with and without preeclampsia.
Methods:
The detection and measurement of 2-OH-ES in the urine of pregnant women were performed by RIA using highly specific antiserum to 2-OH-ES. To confirm the reliability of the RIA method, the same samples were analyzed by HPLC using an electrochemical detector.
Results:
Urinary 2-OH-ES values obtained by RIA showed a close relationship to those obtained by HPLC (y = 1.1x - 0.01; r = 0.96). The urinary 2-OH-ES concentrations during the first, second, and third trimesters were 2. 0 +/- 0.6 (mean +/- SE, n = 13), 5.3 +/- 1.3 (n = 21), and 15.3 +/- 2.0 microg/mg creatinine (n = 54), respectively, and <0.15 microg/mg creatinine (n = 10) at 2-24 h after delivery. The concentrations in preeclamptic women during the third trimester were significantly lower, 3.9 +/- 1.9 microg/mg creatinine (mean +/- SE, n = 12).
Conclusions:
RIA can be used to measure urinary 2-OH-ES during pregnancy. The increase in urinary 2-OH-ES during gestation, its decrease after delivery, and the lower values in preeclampsia are consistent with a role of 2-OH-ES as a placental antioxidant.
