Steroid 21-hydroxylation by human preovulatory follicles from stimulated cycles: a mass spectrometrical study of deoxycorticosterone, 21-hydroxypregnenolone and 11-deoxycortisol in follicular fluid

Exploratory study of the association of steroid profiles in stimulated ovarian follicular fluid with outcomes of IVF treatment

Steroid concentrations in stimulated follicular fluid (sFF) samples have been linked to the quality of oocytes used in IVF treatments. Most of the published studies focused on evaluating the association of the IVF outcomes with only a few of the steroids, measured by immunoassays (IA). We performed a treatment outcome, prospective cohort study using stimulated FF sampled from 14 infertile women undergoing IVF treatment; single oocyte was used per IVF cycle. Fourteen endogenous steroids were analyzed in 22 ovarian follicle aspirations, which corresponded to the embryos used in the IVF. Ten oocytes were associated with live birth (LB) and 12 with no pregnancy (NP). Steroids were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. Differences in distribution of concentrations in association with the pregnancy outcome (LB or NP), and receiver operating characteristic (ROC) curves analysis were performed for the entire cohort and for within-women data. The predominant androgen and estrogen in stimulated sFF were androstenedione (A4) and estradiol (E2), respectively. Lower concentrations of pregnenolone (Pr), lower ratios of A4/ dehydroepiandrosterone (DHEA), testosterone (Te)/DHEA, and greater ratios of E2/Te, and estrone/A4 were observed in sFF samples associated with LB. Among the oocytes associated with NP, in four out of 12 samples total concentration of androgens was above the distribution of the concentrations in the oocytes corresponding to the LB group. Observations of the study indicated increased consumption of precursors and increased biosynthesis of estrogens in the follicles associated with LB. Our data suggest that potentially steroid profiles in sFF obtained during oocyte retrieval may serve as biomarkers for selection of the best embryo to transfer after IVF.

The mislabelling of deoxycorticosterone: making sense of corticosteroid structure and function

Over the 70 or so years since their discovery, there has been continuous interest and activity in the field of corticosteroid functions. However, despite major advances in the characterisation of receptors and coregulators, in some ways we still lack clear insight into the mechanism of receptor activation, and, in particular, the relationship between steroid hormone structure and function remains obscure. Thus, why should deoxycorticosterone (DOC) reportedly be a weak mineralocorticoid, while the addition of an 11β-hydroxyl group produces glucocorticoid activity, yet further hydroxylation at C18 leads to the most potent mineralocorticoid, aldosterone? This review aims to show that the field has been confused by the misreading of the earlier literature and that DOC, far from being relatively inactive, in fact has a wide range of activities not shared by the other corticoids. In contrast to the accepted view, the presence of an 11β-hydroxyl group yields, in corticosterone or cortisol, hormones with more limited functions, and also more readily regulated, by 11β-hydroxysteroid dehydrogenase. This interpretation leads to a more systematic understanding of structure-function relationships in the corticosteroids and may assist more rational drug design.

Liquid chromatography-tandem mass spectrometry applications in endocrinology

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been recognized as a primary methodology for the accurate analysis of endogenous steroid hormones in biological samples. This review focuses on the use of LC-MS/MS in clinical laboratories to assist with the diagnosis of diverse groups of endocrine and metabolic diseases. Described analytical methods use on-line and off-line sample preparation and analytical derivatization to enhance analytical sensitivity, specificity, and clinical utility. Advantages of LC-MS/MS as an analytical technique include high specificity, possibility to simultaneously measure multiple analytes, and the ability to assess the specificity of the analysis in every sample. All described analytical methods were extensively validated, utilized in routine diagnostic practice, and were applied in a number of clinical and epidemiological studies, including a study of the steroidogenesis in ovarian follicles.

Isoforms of 11beta-hydroxysteroid dehydrogenase in human granulosa-lutein cells

To date, two isoforms of 11beta-hydroxysteroid dehydrogenase (11betaHSD) have been characterized: a low affinity, NADP+-dependent isoform (11betaHSD1) and a high affinity, NAD+-dependent isoform which metabolizes dexamethasone and is inhibited by cortisone (11betaHSD2). Having previously reported a relationship between ovarian 11betaHSD activities and conception in women undergoing in vitro fertilization (IVF-ET), the objective of the present study was to identify which isoforms of 11betaHSD metabolize glucocorticoids in cultures of human granulosa-lutein cells. In both intact cells and cell homogenates, two distinct 11betaHSD activities were identified with differing affinities for cortisol (Km = 490 nM and 2.6 microM). Even at low concentrations, cortisol oxidation was preferentially supported by NADP+ and was independent of NAD+. Although inhibited by the hemisuccinate ester of glycyrrhetinic acid, carbenoxolone, the predominant 11betaHSD activity in intact cells was resistant to end-product inhibition. Intact cells were also able to reduce [3H]cortisone (Km = 190 nM) but did not metabolize [3H]dexamethasone. 11BetaHSD1 mRNA was expressed in 23 of 28 cell cultures whereas 11betaHSD2 mRNA was not expressed in any of the 22 independent cultures studied by reverse transcriptase-polymerase chain reaction (RT-PCR). We conclude that human granulosa-lutein cells express both type 11betaHSD and a novel isoform of this enzyme. While the low affinity 11beta-dehydrogenase and 11-ketosteroid reductase activities exhibit properties consistent with 11betaHSD1, the high affinity 11beta-dehydrogenase differs from 11betaHSD2 in that it is NADP+-dependent, does not metabolize dexamethasone and is resistant to end-product inhibition.

Increased follicular fluid total and free cortisol levels during the luteinizing hormone surge

OBJECTIVE

To determine the changes in follicular fluid (FF) total and free cortisol during the LH surge in naturally ovulating women.

PATIENT(S)

Twenty-six women having diagnostic laparoscopy during the follicular phase of normal menstrual cycles were selected.

INTERVENTION(S)

Blood samples were collected 1 day before, the day of, and 1 day after surgery and the results of serum E2 and LH were used to divide the cycles retrospectively into pre- and post-LH surge groups. Follicular fluid was collected during laparoscopy.

MAIN OUTCOME MEASURE(S)

Serum P, total and free cortisol, and FF volume, E2, P, total cortisol, and free cortisol were measured on the day of surgery.

RESULT(S)

Median serum and FF P levels were significantly higher in the post-LH surge group compared with the pre-LH surge group (0.54 versus 1.54 ng/mL [1.7 versus 4.85 nmol/L] and 5.03 versus 28.0 micrograms/mL [15.8 versus 88.0 mumol/L], respectively). Follicular fluid volume also increased significantly after the surge (2.5 versus 4.5 mL). Median serum total and free and percent free cortisol were higher after the surge, although not significantly. In contrast, FF total, free, and percent free levels increased dramatically between pre- and post-LH surge samples (4.41 versus 43.6 ng/mL [16.0 versus 158 nmol/L], 0.138 versus 6.68 ng/mL [0.5 versus 24.2 nmol/L], and 3.3% versus 15.0%, respectively; P < 0.05).

CONCLUSION(S)

An increase in total and free cortisol occurs in the follicle during the LH surge. Cortisol and its regulation by 11 beta-hydroxysteroid dehydrogenase therefore may exert a physiologic role in oocyte maturation or ovulation.

Comparison between steroid hormones and cortisol in serum and follicular fluid in stimulated and unstimulated cycles of in vitro fertilization patients

The present study was undertaken to evaluate the effects of the concentrations of serum and follicular fluid steroids and cortisol levels on the establishment of pregnancies in in vitro fertilization (IVF). Our study group consisted of 42 women (group A) who received gonadotropins for induction of ovulation for IVF. The control group included 23 women (group B) who underwent in vitro fertilization without stimulation. Serum estradiol and progesterone levels were significantly higher in group A than in group B. Serum and follicular fluid cortisol levels were similar in both groups A and B. There was no significant difference in the fertilization rates of the stimulated or unstimulated cycles. However, there were no pregnancies in group B whereas there was a 28.5% pregnancy rate in group A. There were no correlations between the estradiol, progesterone and cortisol levels when compared to the oocyte maturity and the fertilization rates in both groups of patients.

Development and validation of competitive ELISA to determine follicular fluid progesterone concentrations

A simple, direct and reliable heterologous ELISA was developed and validated to determine follicular fluid progesterone concentrations in 10- to 20-mm antral follicles in heifers. A competitive ELISA was developed, using a policlonal antisera raised in New Zealand white rabbits and horseradish peroxidase as label. Standard curve covered a range between 0 and 1 ng per well. The intra- and inter-assay coefficients of variation (CV) were 6.54 and 8.27%, respectively (n = 10). The low detection limit was 1 pg per well with a sensitivity of 50% binding 83.17 pg per well. Comparison of ELISA with RIA showed a correlation coefficient of 0.98. A total of 34 follicles obtained from heifers in the follicular phase of the estrous cycle were tested, and the mean progesterone concentration was 86.72 +/- 20.39 ng/ml. These results were similar to those previously reported for the same species, age, follicular size and stage of cycle.

Studies to confirm the source of 11 beta-hydroxyandrostenedione

In a longitudinal study of 82 children we found a gradual rise in median plasma concentrations of 11 beta-hydroxyandrostenedione (11 beta-OH-A4) from 2.5 to 6.4 nmol/l during childhood which was similar in both sexes. This could reflect changes in adrenal function during the adrenarche and sexual maturation. Plasma concentrations of 11 beta-OH-A4 in adults follow the patterns of cortisol secretion. In patients with diseases of the adrenal cortex, the plasma concentrations of 11 beta-OH-A4 were consistent with the pathology of each condition. In women with polycystic ovaries (PCO) undergoing gonadotrophic stimulation for in vitro fertilization and embryo transfer, 11 beta-OH-A4 (median = 3.8 nmol/l), testosterone and androstenedione, were raised when compared to women with normal ovaries (11 beta-OH-A4 median = 2.6 nmol/l). Follicular fluid has concentrations of 11 beta-OH-A4 six to twelve times greater than plasma levels and in women with PCO, 11 beta-OH-A4 concentrations were lower than in women with normal ovaries, which is consistent with an inhibition of ovarian 11 beta-hydroxylase. Granulosa cells in vitro demonstrated the production of 11 beta-OH-A4 by side chain cleavage of cortisol. These data support an adrenal source for 11 beta-OH-A4 but the raised plasma concentrations in women with polycystic ovary syndrome (PCOS) may reflect the excess androgen output from the ovary. 11 beta-OH-A4 may therefore be an additional marker for ovarian dysfunction.

The determination of 11 beta-hydroxyandrostenedione in human follicular fluid and plasma

The development of a chromatographic/immunoassay method is presented for the measurement of 11 beta-hydroxyandrostenedione (11 beta-OH-A4) in ovarian follicular fluid (FFL) and plasma from women undergoing embryo transfer for in vitro fertilization. This method incorporates high-performance liquid chromatography (HPLC) and permits the simultaneous measurement of other steroids from a single sample in order to assess the intraovarian environment. Authenticity of 11 beta-OH-A4 in follicular fluid was confirmed using selected ion monitoring (SIM) gas chromatography/mass spectrometry (GC/MS). Our results demonstrate a mean concentration of 18.6 nmol/l in follicular fluid compared with 3.2 nmol/l in plasma. The origin of 11 beta-OH-A4 in follicular fluid requires further investigation but these findings supports the hypothesis of ovarian 11 beta-hydroxylase activity on C19 steroids.

Steroid 21-hydroxylase activity in equine ovarian follicles evidenced by isotope dilution-mass spectrometry

Steroid 21-hydroxylase activity of the microsome-enriched fraction of follicular linings from equine ovaries has been demonstrated by gas chromatography-mass spectrometry. The 21-hydroxylated metabolites were quantified by isotope dilution with deuterated analogues. The two most abundant potential substrates for follicular steroid 21-hydroxylase, progesterone (P) and 17-hydroxyprogesterone (17OHP), were converted respectively to 11-deoxycorticosterone (DOC) and 11-deoxycortisol with corresponding apparent specific activities of 308 and 24 pmol/mg protein/h and apparent Km values of 1.1 and 6.4 microM. Competitive inhibition of the P-to-DOC conversion was exerted by 17OHP and pregnenolone. Hence, the ovarian follicle of the mare is an extraadrenal site of preferential DOC biosynthesis by an enzyme having steroid 21-hydroxylase activity.

Cortisol and transcortin in human seminal plasma and amniotic fluid as estimated by modern specific assays

Cortisol concentrations in human seminal plasma, as estimated by the very specific Amersham 'Amerlite' luminescence immunoassay, were 176 +/- 43 (85-260) nmol/l, that is, 63.7 +/- 15.5 (31-94) ng/ml (mean +/- SD, n = 21). This is about 60% of random levels in blood serum and is the first description of cortisol in seminal fluid. In human amniotic fluid at 16-22 weeks of gestation, cortisol concentrations were lower, at 72.6 +/- 14.6 (63-124) nmol/l, that is, 29.3 +/- 5.3 (23-45) ng/ml (n = 21). Concentrations were about 15% of random maternal serum levels in the second trimester of pregnancy. The cortisol concentrations in both fluids were considerably higher than those reported for saliva, which has a mean of about 10 nmol/l. Transcortin (corticosteroid binding globulin, CBG), has been found in human seminal plasma and amniotic fluid for the first time. Concentrations were low, with values up to 12 micrograms/ml, with no significant difference between the two fluids, when using the IRE-Megenix monoclonal iodinated radioimmunoassay. Transcortin concentrations were about 10% of levels in non-pregnant blood serum, compared with about 0.1% for saliva. The higher concentrations of transcortin could perhaps account for the greater diffusion of cortisol into seminal plasma and amniotic fluid. The presence of beta-endorphin, ACTH and cortisol in amniotic fluid, seminal fluid, ovarian follicular fluid, endometrial fluid and gastric fluid may possibly, indicate the existence of a small paracrine ACTH-cortisol axis in the relevant secretory tissues.

Estrogens, androgens, and progestins in follicular fluid from preovulatory follicles: identification and quantification by gas chromatography/mass spectrometry associated with stable isotope dilution

The synthesis and use of stable isotope-labeled analogs of various steroids have made it possible to undertake a study of follicular fluid (FF) aspirated from mature and preovulatory follicles. Our previous results have been brought together here in order to review quantitative work done by gas chromatography-mass spectrometry. A positive gradient between peripheral plasma and FF concentrations of a steroid suggests the possibility of ovarian biosynthesis. This is particularly relevant to the catecholestrogens, 19-norsteroids, and some corticosteroids.

Steroid determinations in human ovarian follicular fluid using capillary gas chromatography

A method is presented based on capillary GLC using both a thermionic and a flame ionization detector to simultaneously analyse all major unconjugated steroids in ovarian follicular fluids (FF). Although specificity can not always be guaranteed for the smaller concentrations of androstenedione and cortisol, accuracy and reproducibility are excellent for the major progestagens and estrogens (progesterone, 17- and 16 alpha-hydroxyprogesterone, pregnenolone, 20 alpha-dihydroprogesterone, estradiol and estrone). Above all the analysis is performed with relatively cheap instrumentation and products. Apart from the "profiles" of unconjugated steroids, a semi-quantitative analysis of steroid conjugates is possible if a preliminary group separation with disposable anion exchanger columns is included.

Deoxycorticosterone secretion by the human ovary

Progesterone (P), deoxycorticosterone (DOC), estradiol-17 beta (E2) and cortisol (F) were determined simultaneously in the peripheral and the ovarian veins in 13 patients. Blood was collected either by direct sampling during laparotomy (12 patients) or by selective catheterization (1 patient). In all ovarian effluents P and E2 levels were significantly higher than in the peripheral vein. This was also true for DOC except in one ovarian effluent. The gradient was higher on the side of the corpus luteum-bearing ovary. P and E2 levels were correlated in ovarian as well as in peripheral veins. In ovarian effluents, DOC gradients were only significantly correlated with P levels (r = 0.63; P less than 0.01) suggesting a metabolic relationship between the two steroids.