A gas chromatographic method for the determination of neutral steroid profiles in urine, including studies on the effect of oxytetracycline administration on these profiles in men

Environmental fate and toxicity of androgens: A critical review

Androgens are released by humans and livestock into the environment and which cause potent endocrine disruptions even at nanogram per liter levels. In this article, we reviewed updated research results on the structure, source, distribution characteristics and the fate of androgens in ecological systems; and emphasized the potential risk of androgens in aquatic organism. Androgens have moderately solubility in water (23.6-58.4 mg/L) and moderately hydrophobic (log Kow 2.75-4.40). The concentration of androgens in surface waters were mostly in ng/L ranges. The removal efficiencies of main wastewater treatment processes were about 70-100%, except oxidation ditch and stabilization ponds. Sludge adsorption and microbial degradation play important role in the androgens remove. The conjugated androgens were transformed into free androgens in environmental matrices. Global efforts to provide more toxicity data and establish standard monitoring methods need a revisit. Of the day available, there is an urgent need for comprehensive consideration of the impact of androgens on the environment and ecology.

Pharmacokinetics of the soybean isoflavone daidzein in its aglycone and glucoside form: a randomized, double-blind, crossover study

BACKGROUND

There are conflicting results in the literature on the bioavailability of isoflavones in the aglycone and the glucoside forms.

OBJECTIVE

The objective was to investigate the pharmacokinetics of the soy isoflavone daidzein (DAI) on oral administration of both the aglycone and glucoside form in a human intervention study. In addition, the pharmacokinetics of the bacterial and oxidative metabolites of DAI was assessed.

DESIGN

Seven German men aged 22-30 y participated in a randomized, double-blind study in a crossover design. After ingestion of pure DAI or pure daidzein-7-O-beta-d-glucoside (DG) (1 mg DAI aglycone equivalent/kg body weight), blood samples were drawn before isoflavone administration and 1, 2, 3, 4.5, 6, 8, 10, 12, 24, and 48 h after the dose. Urine was collected before and 0-6, 6-12, and 12-24 h after the intake of the isoflavones. The concentrations of DAI and its major bacterial and oxidative metabolites in plasma and urine were measured with isotope dilution capillary gas chromatography-mass spectrometry.

RESULTS

The systemic bioavailability (area under the curve; AUC(inf)), the maximal plasma concentration (C(max)), and the cumulative recovery of DAI in urine after administration of DG were 3-6 times greater than after the ingestion of DAI. Except for equol, which was formed by only one volunteer, all other quantified metabolites exhibited 2-12 times greater AUC(inf), C(max), and urinary recoveries after consumption of DG.

CONCLUSION

Our results show that DG exhibits a greater bioavailability than its aglycone when ingested in an isolated form.

Determination of free tetrahydrocortisol and tetrahydrocortisone ratio in urine by liquid chromatography-tandem mass spectrometry

OBJECTIVE

Measurement of urinary free tetrahydrocortisol and tetrahydrocortisone ratio (allo-THF+THF)/THE is clinically important in the diagnosis of hypertension caused by congenital absence of 11beta-hydroxysteroid dehydrogenase type 2 (apparent mineralocorticoid excess, AME) or inhibition of the enzyme after licorice ingestion. Although gas chromatography-mass spectrometry (GC-MS) provides reliable results, it requires derivatization and is lengthy and time-consuming. The purpose of this study was to demonstrate that detection by liquid chromatography-mass spectrometry (LC-MS) is a potentially superior method.

MATERIAL AND METHODS

The analysis utilizes 1 mL urine. The samples were extracted with solid-phase extraction (SPE) using ethyl acetate as eluent. The extract was evaporated to dryness, and allo-tetrahydrocortisol (allo-THF), THF and THE concentrations were analyzed by LC-MS/MS operating in the negative mode after separation on a reversed-phase column. The calibration curves exhibited consistent linearity and reproducibility in the range of 7.5-120 nmol/L. Interassay CVs were 7.0-10 % at mean ratios of (allo-THF+THF)/THE of 0.54-1.9. The detection limit of the analytes was 0.4-0.8 nmol/L (signal-to-noise ratio = 3). The mean recovery of the three analytes ranged from 88 to 95 %. The regression equation for the free ratio using the LC-MS/MS (x) method and the total ratio using the GC-MS (y) method was: y = 0.30x+0.91 (r = 0.61; n = 25).

CONCLUSIONS

The sensitivity and specificity of the LC-MS/MS method offer an advantage over GC-MS by eliminating derivatization. The high costs of equipment are balanced by higher through-put, owing also to shorter chromatographic run times.

Separation and detection of neuroactive steroids from biological matrices

This review is based on a selection of research papers published mainly in the last decade and it describes various analytical aspects of separation and detection of neuroactive steroids in biological matrices.

Alcohol intake, androgen and glucocorticoid steroids in premenopausal women using oral contraceptives: an interventional study

Long-term heavy alcohol intake is associated with endocrinological abnormalities the mechanisms of which are still unclear. The objective of the present study was to investigate the effect of alcohol intake on plasma and urine glucocorticoid and androgen steroid levels in healthy premenopausal women using oral contraceptives. In a placebo-controlled interventional study with a cross-over design including nine premenopausal women using oral contraceptives no effect of tolerance was observed with regard to the magnitude of the acute transient alcohol-induced testosterone elevation after a 1-week alcohol drinking period (0.8 g/kg per day). At non-intoxicated time points elevated plasma testosterone and androstenedione levels were found in the afternoon but not in the morning during the alcohol drinking period compared with placebo. An increase in plasma cortisol levels was observed after the discontinuation of alcohol drinking. No effects were observed in total glucocorticoid conjugates in morning urine spot samples. An increase during the alcohol period relative to placebo was, however, observed in the urine etiocholanolone/androsterone, tetrahydrocortisol/allotetrahydrocortisol as well as the 20-hydroxy-/20-ketosteroid ratios. No consistent effect was observed in the urine (tetrahydrocortisol+allotetrahydrocortisol)/tetrahydrocortisone ratio. It is suggested that the alcohol-induced alterations in plasma glucocorticoid and androgen levels during non-intoxicated conditions are due to a change in the hypothalamic-pituitary-adrenal function. The effects observed in the conjugated urine glucocorticoid and androgen ratios are likely to be mediated by a change in the metabolism of these steroids in the liver. The present results may be of relevance in the development of disturbances in the glucocorticoid as well as sex steroid balance among heavy female drinkers.

Combined profile of androgen glucuro- and sulfoconjugates in post-competition urine of sportsmen: a simple screening procedure using gas chromatography-mass spectrometry

An analytical screening procedure has been developed for the estimation of total androgen conjugates in post-competition urine, using gas chromatography-mass spectrometry with computerized data acquisition and concentration calculation. Rapid acid-catalyzed methanolysis is a key feature of the method, which allows simultaneous cleavage of glucuronides and sulfates. Analytical data generated by this method for testosterone and epitestosterone are in accordance with our previous results obtained by more accurate isotope dilution mass spectrometry. The usefulness of the ratio of testosterone glucuronide-total epitestosterone as an aid for a better discrimination between physiologically high and pharmacologically high ratios of testosterone glucuronide-epitestosterone glucuronide, which was demonstrated previously, has been confirmed here.