Gas chromatography-mass spectrometry of androgens in equine ovarian follicles at ultrastructurally defined stages of development. Identification of 19-nortestosterone in follicular fluid.

Follicular fluid was obtained from equine follicles at different stages of development as determined by ultrastructural study. Gas chromatography-mass spectrometry associated with stable isotope dilution permitted the demonstration of high levels of 4-estrene-3,7-dione and 17 beta-hydroxy-4-estren-3-one, 17 beta-hydroxy-4-estren-3-one levels often being about 10 times higher than those of testosterone. These findings suggest that in the mare ovary, an aromatizing pathway may proceed using these 19-norsteroids as intermediates.

Estrogen 2-, 4-, 6- or 16-hydroxylation by human follicles shown by gas chromatography-mass spectrometry associated with stable isotope dilution.

Follicular fluid, obtained by aspiration of human Graafian follicles in cycles stimulated by clomiphene and hMG + hCG, was analyzed for estrogen content. Carefully controlled extraction and efficient preliminary chromatographic separations were set up. Deuterium labelled analogues were used as internal standards for the quantitative determination by gas chromatography-mass spectrometry and some new derivatives were included in the identification procedure.

Estrogens in seminal plasma of human and animal species: identification and quantitative estimation by gas chromatography-mass spectrometry associated with stable isotope dilution.

Estrone, 2-methoxyestrone and estradiol-17 beta have been definitely identified in seminal plasma of man, bull, boar and stallion by high resolution gas chromatography associated with selective monitoring of characteristic ions of suitable derivatives. Quantitative estimations were performed by isotope dilution with deuterated analogues and by monitoring molecular ions of trimethylsilyl ethers of labelled and unlabelled compounds. Concentrations of unconjugated and total estrogens are reported together with the statistical evaluation of accuracy and precision.