Serum 2-Hydroxyestradiol 17-Sulphate in Pregnancy.

Abstract

Abstract.2-Hydroxyestradiol 17-sulphate (2-OH E2-17-S) is a catecholized form of sulphated estrogen. In vitro studies showed that its antioxidative effect is almost equal to that of free catecholestrogens, such as 2-OH E2 or 4-OH E2 and a-tocoferol, but the existance of 2-OH E2-17-S in human serum has not yet been made clear. 2-OH E2-17-S strongly antagonizes lipid peroxidation, and so it may play an important role in pregnancy, for example as an anti-oxidant in pregnancy-induced hypertension (PIH). The serum level of 2-OH E2-17-S was measured during mid to late pregnancy by a direct radioimmunoassay (RIA) without hydrolysis. The serum levels at 28-31 weeks, 32-35 weeks and 36-40 weeks of gestation were 4.68 ±0.93 (mean ± SE), 8.38 ± 1.21 and 18.31 ± 3.41 nmol/l, respectively.The serum level in PIH cases at 36-40 weeks (4.64± 1.29 nmol/1) was significantly lower than that in normal pregnancy.The 2-OH E2-17-S level in umbilical arteries was significantly higher than that in maternal peripheral vein. These results suggest that the feto-placental unit plays an important role in catecholizing E2-17-S to 2-OH E2-17-S, which may act as an antioxidant in pregnancy.

Comparison of ex vivo inhibitory effect between 2‐hydroxyestradiol and its 17‐sulfate on rat hepatic microsomal lipid peroxidation

“…Recently, we proposed 2-hydroxyestradiol 17-sulfate (2-OH-E 2 -17-S, Scheme 1) as a placental antioxidant based on the following lines of evidence: the increase in plasma (5) or urinary (6) 2-OH-E 2 -17-S concentration with the progress of gestation; a significant difference in the amount present between healthy and preeclamptic pregnancies (6); its strong inhibitory effect on lipid peroxidation (7); and the capacity of the placenta to produce 2-OH-E 2 -17-S from estradiol 17-sulfate (8). To prove our proposal, the antioxidant effect of 2-OH-E 2 -17-S was investigated by conducting ex vivo experiments.…”