Rapid fluorometry of estrogens in nonpregnancy urine, with use of chloroform extraction and purification by anion-exchange chromatography.

International audienceWe describe a new method of extraction and purification of estrogens in low concentration in urine, involving a rapid enzymic hydrolysis of a 10-mL sample, automatic extraction (in a tube) with CHCl3/ethyl acetate, purification by chromatography on a disposable "mini-column" of AG 1-X2, and fluorometry by continuous flow according to Itrich's procedure [Acta Endocrinol. (Copenhagen) 35, 34 (1960)]. Conditions of hydrolysis, extraction, and purification were studied. Within-day precision (CV) was 7.5%, the mean between-day precision 8.5%. The sensitivity was 6 microgram of total estrogens per liter of urine. The specificity was assessed particularly by comparison with the results obtained by Scholler et al. [Acta Endocrinol. (Copenhagen) 57, suppl. 107 (1966)] and by gas-chromatography-mass-spectrometry. The normal limits as calculated by this technique were identical to values reported by others. The technique is rapid; results are obtained in 3 h. It is quite suitable for routine determinations: 100 assays can be done by a team of three technicians in one working day.We describe a new method of extraction and purification of estrogens in low concentration in urine, involving a rapid enzymic hydrolysis of a 10-mL sample, automatic extraction (in a tube) with CHCl3/ethyl acetate, purification by chromatography on a disposable "mini-column" of AG 1-X2, and fluorometry by continuous flow according to Itrich's procedure [Acta Endocrinol. (Copenhagen) 35, 34 (1960)]. Conditions of hydrolysis, extraction, and purification were studied. Within-day precision (CV) was 7.5%, the mean between-day precision 8.5%. The sensitivity was 6 microgram of total estrogens per liter of urine. The specificity was assessed particularly by comparison with the results obtained by Scholler et al. [Acta Endocrinol. (Copenhagen) 57, suppl. 107 (1966)] and by gas-chromatography-mass-spectrometry. The normal limits as calculated by this technique were identical to values reported by others. The technique is rapid; results are obtained in 3 h. It is quite suitable for routine determinations: 100 assays can be done by a team of three technicians in one working day

Conversion, in vitro, of (7n-3H) testosterone to estrone and estradiol-17beta and their 3-sulfate conjugate by the guinea-pig placenta.

International audienceDifferent cellular fractions of guinea-pig placenta were incubated in the presence of (7n-3H) testosterone. Microsomal aromatization of 3H-testosterone into estrone and estradiol-17beta was demonstrated in the presence of NADPH. The predominance of estrone after incubation with 17beta-hydroxylated precursors, (7n-3H) testosterone and (6,7-3H) estradiol-17beta, indicate that there is a microsomal 17beta-hydroxysteroid dehydrogenase activity. In this report, cytosolic sulfurylation of estrogens is demonstrated. This latter activity represents a quite original characteristic of the placental metabolism of estrogens in guinea-pigs. In contrast with the human placenta where there is considerable sulfatase activity, the guinea-pig placenta can sulfurylate estrogens.Different cellular fractions of guinea-pig placenta were incubated in the presence of (7n-3H) testosterone. Microsomal aromatization of 3H-testosterone into estrone and estradiol-17beta was demonstrated in the presence of NADPH. The predominance of estrone after incubation with 17beta-hydroxylated precursors, (7n-3H) testosterone and (6,7-3H) estradiol-17beta, indicate that there is a microsomal 17beta-hydroxysteroid dehydrogenase activity. In this report, cytosolic sulfurylation of estrogens is demonstrated. This latter activity represents a quite original characteristic of the placental metabolism of estrogens in guinea-pigs. In contrast with the human placenta where there is considerable sulfatase activity, the guinea-pig placenta can sulfurylate estrogens