Synthesis of [2-d]estradiol, [4-d]estradiol, [2-t]estradiol and [4-t]estradiol with high specificity

A gas chromatographic/mass spectrometric assay for catechol estrogens in microsomal incubations: comparison with a radiometric assay

A gas chromatographic/mass spectrometric assay for quantifying two catechol estrogens, 2-hydroxyestradiol and 4-hydroxyestradiol, in microsomal preparations is described. The assay employs deuterium-labeled analogs of the catechol estrogens as internal standards and permits quantification of catechol estrogens, in microsomal incubations, at low (1-2) microM concentrations. The compounds are analyzed as their trimethylsilyl derivatives following separation by capillary gas chromatography.

Regulation of aromatic oxidation of estradiol-17 beta in maternal hepatic, fetal hepatic and placental tissues: comparative effects of a series of inducing agents

The effects of nine separate inducers of cytochrome P-450-dependent monooxygenases on the hydroxylation of estradiol-17 beta (E2) were investigated in near-term pregnant rats. Isosafrole exhibited highly effective inducing properties in the maternal liver (20-fold and 5-fold increases in 4- and 2-hydroxylase activities respectively). Pregnenolone 16 alpha-carbonitrile produced approx 20- and 30-fold increases in measured respective rates of 4- and 2-hydroxylase activities in fetal hepatic tissues; isosafrole produced only 2-fold increases in the same reaction. Only minor changes or slight increases in estrogen hydroxylation rates were observed in maternal hepatic, fetal hepatic or placental tissues following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or other potent 3-methylcholanthrene (MC)-like inducing agents (beta-naphthoflavone, MC, caffeine). Phenobarbital exhibited relatively weak inducing properties and exposure of pregnant rats to ethanol from days 3-19 of gestation was without statistically significant effects on the parameters investigated. Rat placentas exhibited extremely low estrogen hydroxylase activities irrespective of pre-exposure of pregnant rats to the inducers studied. The results suggested separate regulatory controls for estrogen 2- and 4-monooxygenase activities even though relatively high correlation between the two reaction were generally observed in all three tissues.