Steroid modulation of human serum albumin binding properties. A spin label study.

The binding isotherm and unique electron spin resonance spectral characteristics of a monoanionic spin label (1-gamma-aminobutyrate-5-N-(1-oxyl-2,2,6,6-tetramethyl-4-aminopiperidinyl)-2,4-dinitrobenzene) and a dianionic spin label (1-glutamate-5-N-(1-oxyl-2,2,6,6-tetramethyl-4-aminopiperidinyl)-2,4-dinitrobenzene) are used to prove the steroid modulation of serum albumin binding properties. Effects of a selected number of steroids (progesterone, testosterone, estradiol, aldosterone, estriol, corticosterone, deoxycorticosterone, hydrocortisone, and cortisone) on the binding isotherm of the monoanionic spin label binding to serum albumin have been determined. At the steroid/albumin ratio of 0.5 to 1, progesterone, testosterone, and estradiol enhance binding of the spin label at all concentrations studied. However, the remaining steroids exert an inhibitory effect at low spin label/albumin ratios and an enhancement effect at high spin label/albumin ratios. Progesterone and cortisone effects on the resonance spectra of the spin label bound to serum albumin confirm the enhancement and displacement properties of these ligands. Thus, like fatty acids, steroids may bind to either the primary or secondary bilirubin binding sites and also allosterically perturb the binding properties of serum albumin. The in vivo importance of the steroid-albumin interaction is discussed.     

Micellar electrokinetic capillary chromatographic separation of steroids in urine by trioctylphosphine oxide and cationic surfactant

Separation of the six structurally similar and hydrophobic neutral steroids, testosterone, dimethyltestosterone, testosterone propionate, cortisone, hydrocortisone and 17-deoxycorticosterone, was achieved by hydrophobic micellar elektrokinetic chromatography. A triphasic separation involving micellar dodecyltrimethylammonium bromide (DTAB), a dynamic bilayer formed due to electrostatic interaction between the silica surface and DTAB, and aqueous phase is proposed to account for the observed separation of the steroids. The running buffer consisted of 0.05 M DTAB and 0.0052 M trioctylphosphine oxide in 0.01 M of phosphate buffer pH 7.4. A detection limit of 500 ng/ml was achieved for each steroid and the application of the method to urine samples is described.     

Simultaneous quantification of 17α-OH progesterone, 11-deoxycortisol, Δ4-androstenedione, cortisol and cortisone in newborn blood spots using liquid chromatography-tandem mass spectrometry

Adrenal steroid profiling, including 17α-OH progesterone (17OHP), 11-deoxycortisol (S), Δ4-androstenedione (Δ4-A) and cortisol (F) in blood spots by tandem mass spectrometry, is used for newborn screening to detect congenital adrenal hyperplasia (CAH). Pre-analytical sample processing is critical for assay specificity and accuracy; however, it is laborious and time-consuming. This study describes the development and validation of a new Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) method for the simultaneous quantification of five steroids: 17OHP, S, Δ4-A, F and cortisone (E) in blood spots from newborns. Whole blood was eluted from a 5.00 mm dried blood spot by an aqueous solution containing the deuterium-labeled internal standards d8-17OHP and d4-cortisol. The steroids extracted from blood spot into aqueous solution were subsequently purified via Extelut mini NT1 column using diethylether. The extracts were evaporated and quantified using LC-MS/MS. The detection limit was 0.25 ng/mL for 17OHP and S, 0.4 ng/mL for Δ4-A and 0.5 ng/mL for F and E. The limit of quantification was 0.5 ng/mL for 17OHP, S and Δ4-A and 1 ng/mL for F and E. Precision for 17OHP, S, Δ4-A at concentrations of 0.5, 2, and 8 ng/mL (n=5) in fortified steroid free serum samples was 1.3-3.5% (intra-assay CV) and 7-14.8% (inter-assay CV). Precision for F and E at concentrations of 5 and 20 ng/mL was 1.5-4.8% (intra-assay, CV%) and 6-15% (inter-assay, CV%). Accuracy was calculated at concentrations of 0.5, 2, and 8 ng/mL for 17OHP, S and Δ4-A and ranged from -0.3 to 0.2%, while for F and E it ranged from -3.2 to 0.2%. Relative recoveries at concentration 2 ng/mL and 8 ng/mL for 17OHP, S, Δ4-A and at 5 ng/mL and 20 ng/mL for F and E ranged from 55% to 80%. Reference intervals were estimated for all steroids in newborns (on day 3). The steroid profile assay herein described is sensitive, specific and accurate and involves a simple pre-analytical sample manipulation; it is therefore suitable for routine analysis and provides data for samples within normal range as well as those with elevated levels. For the first time to our knowledge, cortisone levels are reported in dried blood spots from newborns.     

Standardized LC-MS/MS based steroid hormone profile-analysis

In order to overcome many limitations of immunoassays, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has the potential to find its place in the clinical laboratory medicine for quantification of steroid hormones. A prerequisite for the application of a new analytical procedure in clinical diagnostics is standardization to minimize analytical intra- and interlaboratory variability and inaccuracy. We evaluate a newly standardized HPLC-MS/MS assay in kit-format, developed for routine determination of 16 steroid hormones in human serum samples. Fifteen metabolites can be measured quantitatively, which include aldosterone, androstenedione, androsterone, corticosterone, cortisol, cortisone, 11-deoxycortisol, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), 17β-estradiol (E2), estrone (E1), etiocholanolone, 17α-hydroxyprogesterone (17OHP), progesterone, and testosterone. 11-Deoxycorticosterone is the only compound rated as semi-quantitative in this kit. The sample preparation is performed by solid phase extraction (SPE) on a 96-well plate. The standardized assay has been validated for human serum in terms of lower and upper limit of quantification (LLOQ 0.01-32 ng/mL, ULOQ 5-8000 ng/mL), linear correlation coefficient of calibration (R(2)>0.9966), intra- and inter-day precision (intra-day 1.1-8.8%, inter-day 5.2-14.8% and 8.2-18.6% for 11-deoxycorticosterone), accuracy (intra-day 88.3-115.5% and 109.3-128.2% for 11-deoxycorticosterone, inter-day 91.4-117.2% and 102.3-137.1% for 11-deoxycorticosterone), analytical total error (3.6-17.8%), proficiency test accuracy (85.4-113.4%), recovery (68-99%), and metabolite stability (freeze/thaw stability 95.5-108.1%, short term stability 86.9-107.2%). Inter-assay comparison with a routine reference HPLC-MS/MS assay and seven immunoassays demonstrates the outstanding high performance of this HPLC-MS/MS based kit by improvements in accuracy for progesterone, androstenedione, and 17OHP. Finally, results of two metyrapone tests demonstrate the potential of the standardized HPLC-MS/MS assay for the analysis of a comprehensive steroid hormone profile in clinical diagnostics.     

Simultaneous determination of urinary cortisol, cortisone and corticosterone in parachutists, depressed patients and healthy controls in view of biomedical and pharmacokinetic studies

A rapid and sensitive reversed-phase liquid chromatographic method (RP-LC) with UV detection has been developed for the determination of free cortisol, cortisone and corticosterone in human urine. The assay was performed after a solid-phase extraction procedure (SPE) with dexamethasone as the internal standard. Chromatographic separation was carried out on a Nucleosil 100 C(18) analytical column using a mixture of acetonitrile and water (30 : 70, v/v) as a mobile phase at a flow-rate of 1 mL min(-1). Spectrophotometric detection was performed at 240 nm. The method has been validated for accuracy, precision, selectivity, linearity, recovery and stability. The absolute recoveries of glucocorticoids were above 94.6%. The limits of detection (LOD) and quantification (LOQ) were 0.5 and 2 ng mL(-1), respectively, for all analytes. Linearity was confirmed in the range of 2-300 ng mL(-1) with a correlation coefficient greater than 0.9997 for all steroid hormones. The proposed method was sensitive, robust and specific allowing reliable quantification of steroid hormones. This method was successfully applied for determination of three endogenous glucocorticoid levels in human urine. The studies were performed on 20 sedentary healthy volunteers in comparison to two socially diversified groups, namely 10 parachutists before and after jump and 10 patients with depression. Pharmacokinetic studies performed on these groups indicated that urinary free cortisol and cortisol-to-cortisone ratios can be treated as biomarkers of stress and depressive disorders.     

Pregnene-type steroids and impairment of passive avoidance behavior in rats.

Several pregnene-type steroids, such as progesterone, 19-norprogesterone, dydrogesterone, hydroxydione, corticosterone, deoxycorticosterone, cortisone, and hydrocortisone, were tested on passive avoidance behavior. All steroids except dydrogesterone resulted in an impairment of passive avoidance behavior as shown by decreased avoidance latencies, whereas cortisone appears to have only a weak effect in this respect.     

Sex hormones and corticosteroids in pollen of Pinus nigra

In continuation of earlier investigations on steroid hormones in the pollen of pine, we have isolated and quantitatively determined the following steroids by radioimmunoassay and fluorimetric methods: testosterone, testosterone together with epitestosterone, respectively, and androstenedione; progesterone was determined by radioimmunoassay alone. In addition, we have tried to isolate cortisol, cortisone, 11-deoxycortisol, corticosterone and 11 -deoxycorticosterone and to characterize these compounds by specific reactions. The intensity of these reactions were used to estimate the amounts of corticosteroids in pollen.     

Of 11 candidate steroids,corticosterone concentration standardized for mass is the most reliable steroid biomarker of nutritional stress across different feather types

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Urine metabolomics analysis for adrenal incidentaloma activity detection and biomarker discovery

This study describes the development of a method suitable for the analysis of nineteen major urinary steroid metabolites in human urine. The analytes of interest were isolated from urine using solid phase extraction, subjected to enzymatic hydrolysis and again extracted applying solid phase extraction. After derivatization, methyloxime-trimethylsilyl ether derivatives of steroid hormones were identified by gas chromatography-mass spectrometry (GC/MS) and quantified by gas chromatography with flame ionization detector (GC/FID). The quantification method was validated for linearity, trueness, precision and selectivity. The limits of detection were between 6.2 and 7.2 ng/mL and limits of quantification were between 12.3 and 14.8 ng/mL. The established method was applied to analyze 28 urine samples from patients diagnosed with non-functioning adrenal incidentalomas (AIs) and 30 healthy subjects. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were employed to visualize the differences between metabolic profiles of patients and the control group and to determine possible markers of AIs activity. Both multivariate methods separated seven patients from the rest of the examined individuals. Five urinary metabolites including α-cortol, tetrahydrocorticosterone, tetrahydrocortisol, allo-tetrahydrocortisol and etiocholanolone were identified as potential biomarkers of pathological adrenal function. The altered metabolites reflected pathological metabolism mainly of cortisol and cortisone. This research proved that metabolomics is a suitable tool for disease research.     

A physiological dose of estradiol with progesterone affects striatum biogenic amines

The acute effect of estradiol and progesterone on dopamine and serotonin metabolism in rat striatum was studied. One subcutaneous injection of 17 beta-estradiol (300 ng) and progesterone (150 micrograms) into intact male rats increased plasma levels of these steroids, while testosterone, corticosterone, and estrone remained unchanged. Dehydroepiandrosterone, androstane-3 beta, 17 beta-diol and dihydrotestosterone remained undetectably low. Prolactin decreased and androstane-3 alpha, 17 beta-diol, and 17-OH progesterone increased, but less than estradiol and progesterone. Peak levels of striatal dopamine, dihydroxyphenylacetic acid, and homovanillic acid were observed 15-45 min after steroid injection with a return to control values after 45-60 min, while serotonin and 5-hydroxyindoleacetic acid levels were slightly decreased. An injection of estradiol (70 ng) with progesterone (70 micrograms) to ovariectomized female rats left plasma prolactin levels unchanged, while striatum dopamine and serotonin as well as their metabolite concentrations peaked 15-60 min after steroid injection and returned to control values after 45-75 min. To allow for a better comparison of the action of these steroids, the effect of estradiol or progesterone alone and in combination on the brain of ovariectomized rats was compared in the same experiment. A similar increase in metabolites of dopamine levels was observed after these steroids alone or in combination, while dopamine levels were increased only after progesterone alone or in combination with estradiol. An injection of estradiol or progesterone to ovariectomized rats led to peak steroid concentrations at approximately the same time in the brain and plasma. In addition, plasma and brain steroid levels were significantly correlated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Uptake of erythrocyte-associated component of blood testosterone and corticosterone to rat brain

To study transport of steroids by erythrocytes, the tissue uptake of erythrocyte-associated testosterone and corticosterone was studied in vivo using a single injection technique into the carotid artery of rats. A brain uptake index (BUI) was calculated by dividing the ratio of [3H]steroid to [14C]butanol (internal reference) in the brain tissue by that in the injection material, and multiplying by 100%. BUIs of testosterone and corticosterone in an erythrocyte suspension were 131 +/- 3% (mean +/- SE, n = 6) and 57.0 +/- 2.7% (n = 6), respectively, which were greater than those in buffer (100 +/- 4%; n = 4, P less than 0.01 and 39.8 +/- 4.6%; n = 4, P less than 0.01, respectively). The erythrocyte accounted for 83.9% and 76.7% of the total testosterone and corticosterone delivered to the tissues, respectively, when calculated on the assumption that the BUIs of steroid in buffer and in the supernatant of an erythrocyte suspension are the same. BUIs of corticosterone in hemolysate and in a suspension of erythrocyte plasma membranes (60.8 +/- 7.0%; n = 4 and 69.5 +/- 3.7%; n = 4, respectively) were also greater than those in buffer (P less than 0.05 and P less than 0.01, respectively). Our results suggest that the erythrocyte-associated component of testosterone and corticosterone are delivered to the tissue of rat brain, and that their membranes may play a major role in their capacity to transport steroids to the tissues.     

Influence of commercial collection devices for saliva on the reliability of salivary steroids analysis

Saliva analysis is an accepted non-invasive alternative to plasma in pediatric endocrinology. Although commercial saliva collectors are available, the reliability of these devices for the analysis of salivary hormones has not been proved. We investigated the recovery and linearity of salivary steroids (cortisol, cortisone, 17-hyroxyprogesterone, testosterone, androstenedione) being relevant in endocrine research and therapy control. Pooled saliva was spiked with ascending concentrations of the steroids and applied onto a variety of absorbents, such as the cotton and the polyester (PE) Salivette (Sarstedt), the foam-tip applicator (Whatman) and strips of blood-spot collection paper (Whatman). Analysis was performed by LC-MS/MS. Best results were achieved using the PE Salivette, yielding recoveries (%) of 99.8 (cortisol), 98.7 (cortisone), 91.8 (17OHP), 96.3 (testosterone), 98.9 (androstendione) with a volume recovery of 98+/-1%. Using the blood-spot paper, recoveries (%) were 92.0 (cortisol), 89.1 (cortisone), 72.0 (17OHP), 70.3 (testosterone) and 77.1 (androstendione). The recovery of glucocorticoids was significantly higher compared to androgens (p<0.001). The recovery of liquid volume was 95+/-2%. The cotton Salivette yielded weak recoveries of 88.7 (cortisol), 86.2 (cortisone), 60.9 (17OHP), 62.0 (testosterone) and 72.4 (androstendione). The recovery of the glucocorticoids differed significantly from the androgens (p<0.001). Liquid recovery was most variable with 89+/-8%. The weakest recoveries were found in the foam-tips being 76.2 for cortisol, only 41.8 for cortisone, 31.1 for 17OHP, 38.5 for testosterone and 36.1 for androstendione. The volume recovery here was 97+/-1%. We assume only the PE version of the Salivette suitable for salivary steroid analysis. The weak recovery from the cotton version is a severe problem due to lacking comparability with values obtained with the polyester wads and the weak homogeneity as observed over a physiological concentration range.     

The corticosteroid metabolic profile of the mouse

Data are presented on the urinary corticosteroid metabolic profile of the mouse strain 129/svJ. Through the use of GC/MS we have characterized, or tentatively identified corticosterone (Kendall's compound B) metabolites of both the 11beta-hydroxy and 11-carbonyl (compound A) series in urine. Full mass spectra of the methyloxime-trimethylether derivatives of 15 metabolites are included in the paper as an aid to other researchers in the field. Metabolites ranged in polarity from tetrahydrocorticosterone (THB) to dihydroxy-corticosterone with dominance of highly polar steroids. We found that prior to excretion corticosterone can undergo oxidation at position 11beta, reduction at position 20 and A-ring reduction. Metabolites retaining the 3-oxo-4-ene structure can be hydroxylated at position 6beta- as well as at an unidentified position, probably 16alpha-. Saturated steroids can be hydroxylated at positions 1beta-, 6alpha-, 15alpha- and 16alpha. A pair of hydroxy-20-dihydro-corticosterone metabolites (OH-DHB) were the most important excretory products accounting for about 40% of the total. One metabolite of this type was identified as 6beta-hydroxy-DHB; the other, of similar quantitative importance was probably 16alpha-hydroxy-DHB. The ratio of metabolites of corticosterone (B) to those of 11-dehydro-corticosterone (A) was greater than 9:1, considerably higher than that for the equivalent "human" ratio of 1:1 for cortisol to cortisone metabolites. Results from this study allowed the evaluation of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) activity in mice with deleted glucose-6-phosphate transporter (G6PT). These mice had attenuated back-conversion of A to B resulting in an increased ratio of A-metabolites to B-metabolites [Walker EA, Ahmed A, Lavery GG, Tomlinson JW, Kim SY, Cooper MS, Stewart PM, 11beta-Hydroxysteroid dehydrogenase type 1 regulation by intracellular glucose-6-phosphate, provides evidence for a novel link between glucose metabolism and HPA axis function. J Biol Chem 2007;282:27030-6]. We believe this study is currently the most comprehensive on the urinary steroid metabolic profile of the mouse. Quantitatively less steroid is excreted in urine than in feces by this species but urine analysis is more straightforward and the hepatic metabolites are less subject to microbial degradation than if feces was analyzed.     

Gas chromatographic and mass spectrometric analysis of conjugated steroids in urine

This study was carried out qualitatively and quantitatively to investigate the presence and the concentrations of anabolic steroids in urine collected from orally administered humans. Microanalysis of conjugated steroids by gas chromatography and mass spectrometry (GC/MS) has been carried out. Following oral administration three major metabolites of anabolic steroid drugs have been detected and partially characterized. The six steroids can be analysed at the same time in 17 min. The lower detection limit was 10 ng/ml in 5 ml of urine. The conjugated steroids from urine were centrifuged to 2,430g for 10 min, the supernatant solution passed through Amberlite XAD-2 column and the steroids eluted fraction esterified by using MSTFA and TMSI. The rate of metabolism and urinary excretion seem to be reasonably fast.     

Population based evaluation of a multi-parametric steroid profiling on administered endogenous steroids in single low dose

Steroid profiling provides valuable information to detect doping with endogenous steroids. Apart from the traditionally monitored steroids, minor metabolites can play an important role to increase the specificity and efficiency of current detection methods. The applicability of several minor steroid metabolites was tested on administration studies with low doses of oral testosterone (T), T gel, dihydrotestosterone (DHT) gel and oral dehydroepiandrosterone (DHEA). The collected data for all monitored parameters were evaluated with the respective population based reference ranges.Besides the traditional markers T/E, T and DHT, minor metabolites 4-OH-Adion and 6α-OH-Adion were found as most sensitive metabolites to detect oral T administration. The most sensitive metabolites for the detection of DHEA were identified as 16α-OH-DHEA and 7β-OH-DHEA but longest detection up to three days (after oral administration of 50 mg) was obtained with non-specific 5β-steroids and its ratios. Steroids applied as a gel had longer effects on the metabolism but were generally not detectable with universal decision criteria.It can be concluded that population based reference ranges show limited overall performance in detecting misuse of small doses of natural androgens. Although some minor metabolites provide additional information for the oral testosterone and DHEA formulations, the topical administered steroids could not be detected for all volunteers using universal reference limits. Application of other population based threshold limits did not lead to longer detection times.     

Development of a liquid chromatography-tandem mass spectrometry method for the determination of 23 endogenous steroids in small quantities of primate urine

A quantitative method using liquid chromatography-tandem mass spectrometry (LC-MS-MS) was developed for the simultaneous determination of 23 endogenous steroids in primate urine. The introduced method includes estrone, pregnandiol, cortisol, testosterone and several human urinary glucocorticoid and androgen metabolites. As the method is intended for the analysis of steroid hormones in behavioral studies on wild-living primates, it was adapted for a sample volume of 200microL urine. The sample preparation consisted of an enzymatic hydrolysis of steroid glucuronides using beta-glucuronidase from E. coli followed by a solvolytic cleavage of steroid sulfates employing sulfuric acid/ethyl acetate. The extraction of steroids from urine was optimized with respect to pH during extraction, type of ether and the amount of enzyme necessary for complete hydrolysis of glucuronides. The recovery of steroids spiked into urine before hydrolysis was 58.9-103.7% with an intra-day precision of 2.7-14.3% and an inter-day precision of 2.9-14.8%. Detection limits ranged from 0.1-0.5ng/mL. The reproducibility of the whole sample preparation process was also demonstrated for unspiked urine (CV 1.2-16.5%). The proportion of steroid hormone excreted as sulfate was determined for 21 steroids in chimpanzee urine. The solvolysis proved to be essential for all investigated steroids except for pregnandiol, tetrahydrocortisol and tetrahydrocortisone, which were found to be less then 10% in the solvolysis fraction.     

An in vitro microdialysis methodology to study 11beta-hydroxysteroid dehydrogenase type 1 enzyme activity in liver microsomes

Microdialysis sampling coupled with liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS/MS) was used to observe in vitro 11beta-hydroxysteroid dehydrogenase type 1 (HSD1) enzyme-catalyzed conversion of stable-isotope-labeled cortisone to cortisol in liver microsomes from dog, monkey, and human. Experimental conditions that would affect the microdialysis sampling approach including probe length, perfusion fluid flow rate, extraction efficiency (E(d)), substrate concentration, and enzyme reaction conditions were evaluated. Dialysates containing high salt concentrations (>150 mM) were directly assayed using LC/MS/MS without additional sample cleanup. The sensitivity (with lower level of quantitation at 0.1 ng/mL) and selectivity of this assay allowed detection of the enzyme reactants at physiologically relevant levels. The interconversion from M+4 cortisone to M+4 cortisol was detected in dog, human, and monkey liver microsomes. Results show species-specific reaction profiles, with a five times higher conversion rate in dog liver microsomes than in human and monkey liver microsomes. Based on M+4 cortisol production rate obtained using a microdialysis infusion of M+4 cortisone to the microsomes coincubated with a proprietary 11beta-HSD1 inhibitor of different concentrations, the degrees of enzyme inhibition were found to be 40 and 85%, consistent with values obtained by a traditional in vitro incubation method. The microdialysis sampling methodology with LC/MS/MS provided extensive information about 11beta-HSD1 activities in microsomes from different mammalian species.     

Comparative studies of HPLC-fluorometry and LC/MS method for the determination of N-acetylneuraminic acid as a marker of deteriorated ophthalmic solutions

Methods for determining the deterioration of ophthalmic solutions using both high-performance liquid chromatography (HPLC) with fluorescence detection and liquid chromatography coupled with selected ion monitoring mass spectrometry (LC/MS) are described. The methods are based on the determination of N-acetylneuraminic acid (NeuAc) released by the hydrolysis of foreign bodies that contaminate eye drops during use. The released NeuAc was either labeled with 1,2-diamino-4,5-methylenedioxybenzene (DMB) for fluorometric detection or detected without derivatization by mass spectrometry. The calibration curves for NeuAc showed good linearity between 1.2 ng/mL and 39 ng/mL for fluorometric HPLC and 5.0 ng/mL and 100 ng/mL for LC/MS, respectively. Detection limits for fluorometric HPLC and LC/MS were 0.20 ng/mL and 0.88 ng/mL, respectively. The NeuAc content of some model glycoproteins determined by LC/MS method were 62-78% of those determined by fluorometry. The differences are attributed to matrix effects but the LC/MS method afforded sufficiently high sensitivity that NeuAc in the foreign bodies could be determined in eight of nine test samples.     

Studies on the metabolism of steroid hormones in a virilizing adrenal cortex adenoma.

Slices of an adreno-cortical adenoma which had been obtained at operation from an 11-year-old girl with clinical signs of virilism were incubated with each of the following steroids: [1,2-3H]progesterone, [4-14C]pregnenolone, [1,2-3H]testosterone, [4-14C]androstenedione and [7-3H]dehydroepiandrosterone, respectively. Isolation and identification of the free radioactive metabolites were achieved by gel column chromatography on Sephadex LH-20, thin-layer chromatography, radio gas chromatography and isotope dilution. After incubation of progesterone, the following metabolites were identified: 11beta-hydroxyprogesterone, 16alpha-hydroxyprogesterone, 17alpha-hydroxyprogesterone, 21-deoxycortisol, corticosterone and cortisol. Pregnenolone was metabolized to 17alpha-hydroxypregnenolone, progesterone, dehydroepiandrosterone, androstenedione and 11beta-hydroxyandrostenedione. When testosterone was used as substrate, 11beta-hydroxytestosterone, androstenedione and 11beta-hydroxyandrostenedione were found as metabolites, whereas androstenedione was metabolized to testosterone and 11beta-hydroxyandrostenedione. After incubation of dehydroepiandrosterone, only androstenedione and 11beta-hydroxyandrostenedione were isolated and identified. From these results, it appears that cortisol was formed in the adenoma tissue via 21-deoxycortisol and corticosterone. Delta4-3oxo steroids of the C19-series arose exclusively from pregnenolone via 17alpha-hydroxypregnenolone and dehydroepiandrosterone, and not from progesterone and 17alpha-hydroxyprogesterone. Calculated on the amounts of metabolites formed, the highest enzyme activities were those of the 11beta-hydroxylase and the 17alpha-hydroxylase. It is interesting to note that only traces of testosterone were detected after incubation of androstenedione, whereas testosterone yielded large amounts of androstenedione.     

Simultaneous determination of serum cortisol and cortisone by reversed-phase liquid chromatography with ultraviolet detection

A rapid high-performance liquid chromatographic (HPLC) method for the simultaneous determination of cortisol and cortisone in a single extract of 1 ml of serum is described. The method employs meprednisone as the internal standard. The steroids were analysed isocratically by reversed-phase HPLC with an octadecylsilane-bonded (ODS) column using ultraviolet detection. The matrix effect was reduced by lowering the sample pH by adding glacial acetic acid to the sera. The samples were then filtered through regenerated cellulose membranes at 4°C and extracted with diethyl ether. The dried eluates were redissolved in the mobile phase and injected into the column. The detection limit of the assay for both steroids was 500 ng/l. Cortisol was determined in twenty serum samples by both HPLC and radioimmunoassay (RIA). The results were similar. Interference by other steroids and certain steroid analogue drugs was also studied. The HPLC method yielded no cross-reactivity between the different steroids as may occur with the RIA technique. The HPLC method was technically easy to perform and it allowed us to quantify both cortisol and cortisone in a single serum extract with high specificity.