Characterizing the steroidal milieu in amniotic fluid of mid-gestation: A LC-MS/MS study.

Growth and development of an embryo or fetus during human pregnancy mainly depend on intact hormone biosynthesis and metabolism in maternal amniotic fluid (AF). We investigated the hormonal milieu in AF and developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of 14 sulfated and 6 unconjugated steroids in AF. 65 A F samples (male: female = 35: 30) of mid-gestation ranging from 16th week of gestation to 25th week of gestation were analyzed. Reference data of 20 steroid levels in AF of healthy women were provided. 13 sulfated and 3 unconjugated steroids were for the first time quantified in AF by LC-MS/MS. Highest concentrations were found for pregnenolone sulfate (PregS: mean ±â€¯SD, 8.6 ±â€¯3.7 ng/mL), 17α-hydroxypregnenolone sulfate (17OHPregS: 4.9 ±â€¯2.0 ng/mL), epitestosterone sulfate (eTS: 7.3 ±â€¯3.6 ng/mL), 16α-hydroxydehydroepiandrosterone sulfate (16OH-DHEAS: 21.5 ±â€¯10.7 ng/mL), androsterone sulfate (AnS: 9.2 ±â€¯7.4 ng/mL), estrone sulfate (E1S: 3.0 ±â€¯3.0 ng/mL), estriol 3-sulfate (E3S: 8.1 ±â€¯4.0 ng/mL) and estriol (E3: 1.2 ±â€¯0.4 ng/mL). Only testosterone (T) showed a significant sex difference (p < 0.0001). Correlations between AF steroids mirrored the steroid metabolism of the feto-placental unit, and not only confirmed the classical steroid pathway, but also pointed to a sulfated steroid pathway.

Determination of two progestin metabolites (17α-hydroxypregnanolone and pregnanediol) and different classes of steroids (androgens, estrogens, corticosteroids, progestins) in rivers and wastewaters by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

A highly sensitive and robust method was developed for routine analysis of two progestin metabolites, 17α-hydroxypregnanolone (17OH-Δ5P) and pregnanediol (PD), and 31 other natural and synthetic steroids and related metabolites (estrogens, androgens, corticosteroids, progestins) in river water, as well as influents and effluents of municipal wastewater treatment plants (WWTP) using HPLC-MS/MS combined with solid-phase extraction. For the various matrixes considered, the optimized method showed satisfactory performance with recoveries of 70-120% for most of target steroids. The method detection limits (MDLs) ranged from 0.01 to 3ng/L for river water, 0.02 to 10ng/L for WWTP effluents, and 0.1 to 40ng/L for influents with good linearity and reproducibility. The developed method was successfully applied for the analysis of steroids in rivers and WWTP influent and effluents. WWTP influents concentrations of 17OH-Δ5P and PD were 51-256ng/L and up to 400ng/L, respectively, along with androstenedione (concentration range: 38-220ng/L), testosterone (11-26ng/L), estrone (2.3-37ng/L), 17ß-estradiol (N.D.-8.7ng/L), 17α-hydroxyprogesterone (N.D.-66ng/L), medroxyprogesterone acetate (N.D.-5.3ng/L), and progesterone (2.0-22ng/L), while only androstenedione (ADD), estrone (E1), and estriol (E3) were detected in effluent with concentrations ranging up to 1.7ng/L, 0.90ng/L and 0.8ng/L, respectively. In river water samples, only ADD and E1 were detected with concentrations up to 1.0ng/L and 0.91ng/L. Our procedure represents the first method for analyzing 17OH-Δ5P and PD in environmental samples along with a large series of steroids.

Determination of 17OHPreg and DHEAS by LC-MS/MS: Impact of Age, Sex, Pubertal Stage, and BMI on the Δ5 Steroid Pathway.

Background: Dehydroepiandrosterone sulfate (DHEAS) and 17-hydroxypregnenolone (17OHPreg) are important for understanding the Δ5 pathway (e.g., in adrenarche and obesity). Although mass spectrometry has become the state-of-the-art method for quantifying steroids, there are few comprehensive age-, sex-, and pubertal stage-specific reference ranges for children. Aims: To develop a sensitive and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous quantification of DHEAS and 17OHPreg and to establish entire age-, sex- and pubertal stage-specific reference ranges in children. Methods: A total of 684 children, 453 (243 female, 210 male) with normal body mass index (BMI; <90th) and 231 (132 female, 99 male) obese subjects (>97th), were categorized into 11 age groups, and age- and Tanner stage (PH)-specific reference ranges were determined. Results: The limit of detection was 0.05 nmol/L for 17OHPreg and 0.5 nmol/L for DHEAS. Levels of both steroids declined after the neonatal period. Comparisons with RIA assays (Siemens, Munich, Germany) (DHEAS) and an in-house kit (17OHPreg) revealed 0.95 and 0.93, respectively, as coefficients of determination. Although DHEAS-generally higher in boys-increased continuously starting at 3 to 6 years, 17OHPreg remained largely constant. In obese patients, both were significantly elevated, also in part after alignment to Tanner stages (PH). Conclusions: UPLC-MS/MS is sensitive and reliable for quantifying DHEAS and 17OHPreg. Our data support differential maturation of CYP17 during adrenarche with successively increasing 17,20-lyase activity but largely constant 17α-hydroxylation activity. Endocrine interpretation of 17OHPreg and DHEAS must consider differential patterns for age, sex, pubertal stage, and BMI.

Metabolism of [17-2H]pregnenolone into 5-[17 beta-2H, 17 alpha-18O]androstene-3 beta, 17 alpha-diol and other products by incubation with the microsomal fraction of boar testis under 18O2 atmosphere.

[17-2H]Pregnenolone was incubated with the microsomal fraction of boar testis under an 18O2 atmosphere. The metabolites were analyzed by gas chromatography-mass spectrometry, and the following six metabolites labeled with 2H or 18O (or both) were identified: 17 alpha-[17-18O]hydroxypregnenolone, [17-18O]dehydroepiandrosterone, 5-[17-18O]androstene-3 beta, 17 beta-diol, 16 alpha-[16-18O]hydroxy[17-2H]pregnenolone, 5-[17 beta-2H, 17-18O]androstene-3 beta,17 alpha-diol, and 5,16-[17-2H]androstadien-3 beta-ol. The time course of the formation of these metabolites from pregnenolone was also studied using 14C-labeled substrate. The results obtained from these experiments suggest that the first three metabolites were synthesized by a well-documented pathway--pregnenolone yields 17 alpha-hydroxypregnenolone yields dehydroepiandrosterone yields 5-androstene-3 beta,17 beta-diol--, and that 16 alpha-hydroxypregnenolone, 5-androstene-3 beta,17 alpha-diol and 5,16-androstadien-3 beta-ol were synthesized from [17-2H]pregnenolone with retention of 17-2H.

Covalent coupling of a steroid to microwell plates for use in a competitive enzyme-linked immunosorbent assay.

The covalent coupling of a model steroid, 17 alpha-hydroxypregnenolone, to the wells of the microtiter plate, CovaLink NH, for use in a competitive enzyme-linked immunosorbent assay is described. This plate has secondary amino groups bound to its surface. A carboxylated derivative of the steroid was coupled to the amino group to form an amide bond in a single step using a water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (10 mM) as coupling reagent in the presence of N-hydroxysuccinimide (1 mM). After carrying out a competitive immune reaction, antibodies bound to immobilized steroids were estimated by means of a second antibody-enzyme conjugate. The non-specific background was reduced with blocking agents which did not interfere with the immune reaction between antibodies and the steroids coupled to the plastic surface. The following two procedures were effective for this purpose: pretreatment of wells with 0.01% Tween 20 solution followed by 0.5% bovine serum albumin in phosphate buffered saline, and addition of 0.01% Tween 20 to the assay buffer. With this method, the preparation of steroid-enzyme conjugates is unnecessary and optimization of conditions for ELISA procedures can be achieved in a simple manner.

Virilizing adrenocortical adenoma: in vitro steroidogenesis, immunohistochemical studies of steroidogenic enzymes, and gene expression of corticotropin receptor.

BACKGROUND: No reports have yet precisely determined corticotropin (ACTH) responsiveness in virilizing adrenocortical adenoma. METHODS: Five women with an androgen-secreting adrenal adenoma were reviewed. Three of them were examined by in vitro steroidogenesis. Two of these 3 patients were studied by immunohistochemistry of steroidogenic enzymes and for the gene expression of ACTH receptor by Northern blot analysis. RESULTS: In preoperative hormonal determinations plasma and urine androgens had increased. Dexamethasone did not suppress plasma and urinary androgens, nor did ACTH increase them. In vitro steroidogenesis revealed that the adenoma cells produced mainly dehydroepiandrosterone and a small amount of testosterone. ACTH did not increase the in vitro production of androgens. In immunohistochemical staining 5 enzymes involved in adrenal steroidogenesis were all expressed, especially 17 alpha-hydroxylase, which was strongly expressed in tumor cells. ACTH receptor messenger RNA was not detected in virilizing tumor tissues, whereas it was expressed in attached adrenal tissues. CONCLUSIONS: The lack of response to ACTH is the result of a deficiency of ACTH receptor expression in the virilizing tumor cells. Androgens were autonomously produced in adrenal adenoma cells without ACTH regulation.

Synthesis of (19E)-3 beta,17-dihydroxy-20-oxopregn-5-en-19-al 19-(O-carboxymethyl)oxime, new steroidal hapten for 17-hydroxypregnenolone.

A synthesis of (19E)-3 beta,17-dihydroxy-20-oxopregn-5-en-19-al 19-(O-carboxymethyl)oxime (15), is reported. Hydride reduction of ketone 1 gave the (20R)-hydroxy derivative 2 as the main product. Formylation of 2 followed by cleavage of the epoxide ring and mild Jones oxidation afforded aldehyde 6. Oximation with (O-carboxymethyl)hydroxylamine and subsequent methylation yielded methyl ester 8 which was selectively hydrolyzed to alcohol 9 and oxidized to ketone 10. Enolacetylation, epoxidation, and hydrolysis led to the desired 19-(O-carboxymethyl)oxime derivative of 17-hydroxypregnenolone 15.

Simultaneous determination of pregnenolone and 17α-hydroxypregnenolone by semi-micro high-performance liquid chromatography with an immobilized cholesterol oxidase as a pre-column reactor: application to bovine adrenal fasciculata cells.

A method for the simultaneous determination of pregnenolone and 17α-hydroxypregnenolone by high-performance liquid chromatography with an immobilized cholesterol oxidation enzyme reactor was developed. Pregnenolone and 17α-hydroxypregnenolone were converted to progesterone and 17α-hydroxyprogesterone, respectively, by the immobilized enzyme packed into the reactor column, and could thus be monitored by UV absorption at 240 nm. The calibration curves for pregnenolone and 17α-hydroxypregnenolone were linear in the range of 0.4-10 and 0.3-10 µg/ml with a correlation coefficient of 0.9993 and 0.9998, respectively. The detection limit at a signal-to-noise ratio of 3 was 0.12 and 0.08 µg/ml for pregnenolone and 17α-hydroxypregnenolone, respectively. The conversion rate of pregnenolone to progesterone and 17α-hydroxypregnenolone to 17α-hydroxyprogesterone was 90.6% and 99.3%, respectively. Intra-day and inter-day precision (in terms of percentage coefficient of variation) were less than 9.3%, with accuracy greater than 94.8%. This method was successfully applied to the simultaneous determination of pregnenolone and 17α-hydroxypregnenolone secreted into the culture medium of bovine adrenal fasciculata cells and of both analytes produced within the cells.

Prolactin increases the synthesis of 7alpha-hydroxypregnenolone, a key factor for induction of locomotor activity, in breeding male Newts.

We recently found that the Japanese red-bellied newt, Cynops pyrrhogaster, actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. 7alpha-Hydroxypregnenolone stimulates locomotor activity of male newts. Locomotor activity of male newts increases during the breeding period as in other wild animals, but the molecular mechanism for such a change in locomotor activity is poorly understood. Here we show that the adenohypophyseal hormone prolactin (PRL) stimulates 7alpha-hydroxypregnenolone synthesis in the brain, thus increasing locomotor activity of breeding male newts. In this study, cytochrome P450(7alpha) (CYP7B), a steroidogenic enzyme catalyzing the formation of 7alpha-hydroxypregnenolone, was first identified to analyze seasonal changes in 7alpha-hydroxypregnenolone synthesis. Only males exhibited marked seasonal changes in 7alpha-hydroxypregnenolone synthesis and CYP7B expression in the brain, with a maximum level in the spring breeding period when locomotor activity of males increases. Subsequently we identified PRL as a key component of the mechanism regulating 7alpha-hydroxypregnenolone synthesis. Hypophysectomy decreased 7alpha-hydroxypregnenolone synthesis in the male brain, whereas administration of PRL but not gonadotropins to hypophysectomized males caused a dose-dependent increase in 7alpha-hydroxypregnenolone synthesis. To analyze the mode of PRL action, CYP7B and the receptor for PRL were localized in the male brain. PRL receptor was expressed in the neurons expressing CYP7B in the magnocellular preoptic nucleus. Thus, PRL appears to act directly on neurosteroidogenic magnocellular preoptic nucleus neurons to regulate 7alpha-hydroxypregnenolone synthesis, thus inducing seasonal locomotor changes in male newts. This is the first report describing the regulation of neurosteroidogenesis in the brain by an adenohypophyseal hormone in any vertebrate.