Novel H6PDH mutations in two girls with premature adrenarche: 'apparent' and 'true' CRD can be differentiated by urinary steroid profiling.

CONTEXT: Inactivating mutations in the enzyme hexose-6-phosphate dehydrogenase (H6PDH, encoded by H6PD) cause apparent cortisone reductase deficiency (ACRD). H6PDH generates cofactor NADPH for 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1, encoded by HSD11B1) oxo-reductase activity, converting cortisone to cortisol. Inactivating mutations in HSD11B1 cause true cortisone reductase deficiency (CRD). Both ACRD and CRD present with hypothalamic-pituitary-adrenal (HPA) axis activation and adrenal hyperandrogenism. OBJECTIVE: To describe the clinical, biochemical and molecular characteristics of two additional female children with ACRD and to illustrate the diagnostic value of urinary steroid profiling in identifying and differentiating a total of six ACRD and four CRD cases. DESIGN: Clinical, biochemical and genetic assessment of two female patients presenting during childhood. In addition, results of urinary steroid profiling in a total of ten ACRD/CRD patients were compared to identify distinguishing characteristics. RESULTS: Case 1 was compound heterozygous for R109AfsX3 and a novel P146L missense mutation in H6PD. Case 2 was compound heterozygous for novel nonsense mutations Q325X and Y446X in H6PD. Mutant expression studies confirmed loss of H6PDH activity in both cases. Urinary steroid metabolite profiling by gas chromatography/mass spectrometry suggested ACRD in both cases. In addition, we were able to establish a steroid metabolite signature differentiating ACRD and CRD, providing a basis for genetic diagnosis and future individualised management. CONCLUSIONS: Steroid profile analysis of a 24-h urine collection provides a diagnostic method for discriminating between ACRD and CRD. This will provide a useful tool in stratifying unresolved adrenal hyperandrogenism in children with premature adrenarche and adult females with polycystic ovary syndrome (PCOS).

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.

11beta-hydroxysteroid dehydrogenase type 1 activity in lean and obese males with type 2 diabetes mellitus.

Glucocorticoids play an important role in the pathogenesis of obesity and insulin resistance. Impaired conversion of cortisone (E) to cortisol (F) by the type 1 isoenzyme of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) in obesity may represent a protective mechanism preventing ongoing weight gain and glucose intolerance. We have studied glucocorticoid metabolism in 33 male subjects with type 2 diabetes mellitus [age, 44.2 +/- 13 yr; body mass index (BMI), 31.1 +/- 7.5 kg/m(2) (mean +/- sd)] and 38 normal controls (age, 41.4 +/- 14 yr; BMI, 38.2 +/- 12.8 kg/m(2)). Circulating F:E ratios were elevated in the diabetic group and correlated with serum cholesterol and homeostasis model assessment-S. There was no difference in 11beta-HSD1 activity between diabetic subjects and controls. In addition, 11beta-HSD1 activity was unaffected by BMI in diabetic subjects. However, in control subjects, increasing BMI was associated with a reduction in the urinary tetrahydrocortisol+5alpha-tetrahydrocortisol:tetrahydrocortisone ratio (P < 0.05) indicative of impaired 11beta-HSD1 activity. The degree of inhibition correlated tightly with visceral fat mass. Changes in 11beta-HSD1 activity could not be explained by circulating levels of adipocytokines. Impaired E to F metabolism in obesity may help preserve insulin sensitivity and prevent diabetes mellitus. Failure to down-regulate 11beta-HSD1 activity in patients with diabetes may potentiate dyslipidemia, insulin resistance, and obesity. Inhibition of 11beta-HSD1 may therefore represent a therapeutic strategy in patients with type 2 diabetes mellitus and obesity.

Paralogues of porcine aromatase cytochrome P450: a novel hydroxylase activity is associated with the survival of a duplicated gene.

The gonadal and placental paralogues of porcine aromatase cytochrome P450 (P450arom) were examined for novel catalytic properties to shed light on the evolutionary survival of duplicated copies of an enzyme critical to reproduction. Recombinant gonadal P450arom catalyzed the formation of a novel metabolite from testosterone, identified by gas chromatography/mass spectrometry and biochemical analyses as 1 beta-hydroxytestosterone (1 beta OH-T), in almost equal proportion to 17beta-estradiol (E(2)). This activity was absent in reactions with the porcine placental paralogue (or other orthologues) of P450arom and was minimal with androstenedione. Incubations with both porcine enzymes and with bovine and human P450arom demonstrated that 1 beta OH-T was not aromatizable, and 1 beta OH-T activated the androgen receptor of prostate cancer cells in vitro. Porcine testicular and follicular granulosa tissues synthesized 1 beta OH-T, which was also detected in testicular venous plasma. These results constitute the first of identification of a novel, perhaps potent, nonaromatizable metabolite of testosterone, whose synthesis (paradoxically) can be definitively ascribed to the activity of the gonadal paralogue of porcine P450arom. It probably represents an evolutionary gain of function associated with fixation and the survival of the genes after CYP19 duplication. Novel activities and adaptive functions may exist among other duplicated vertebrate aromatases.

Congenital hypopituitarism as a cause of undetectable estriol levels in the maternal triple-marker screen.

We are reporting a child with congenital panhypopituitarism, in whom deficient fetal steroidogenesis was suspected prenatally because of undetectable estriol levels measured in the maternal triple-marker screen. No fetal abnormalities were detected by ultrasonography. Amniocentesis demonstrated a normal 46,XX karyotype. Measurement of maternal urinary steroids failed to show elevation in the excretion of the major precursor for estriol, 16 alpha-hydroxydehydroepiandrosterone, indicating that the fetus did not have steroid sulfatase deficiency (placental sulfatase deficiency), the most common genetic cause of extremely low estriol. The steroid analysis excluded other rare single gene defects, including aromatase deficiency and 17 alpha-hydroxylase deficiency. We therefore suspected that the cause of low estriol in this fetus was adrenal insufficiency. Postnatal evaluation was consistent with panhypopituitarism, characterized by deficiency of all anterior pituitary hormones. Because this screen is now offered to more than half the pregnant women in the United States, reports of low estriol levels have become increasingly common. Therefore, it is essential that physicians be familiar with the various etiologies, perform the appropriate antenatal evaluation to determine the specific cause, and closely monitor both mother and child ante- and postnatally.

Measuring synthesis rates of muscle creatine kinase and myosin with stable isotopes and mass spectrometry.

We investigated a novel strategy for measuring the synthesis rate of proteins in skeletal and cardiac muscle. Mass isotopomer distribution analysis allows measurement of the isotopic enrichment of the true biosynthetic precursor for proteins (tRNA-amino acids), but cannot easily be applied to slow turnover muscle proteins due to insufficient isotope incorporation into multiply labeled species. Using a rapid turnover protein from the same tissue, however, might reveal tRNA-amino acid enrichment. We tested this strategy in rats on muscle creatine kinase (CK). A trypsinization peptide (3647u) containing 5 leucine repeats was identified by computer-simulated digestion of CK and then isolated from trypsin hydrolysates. Mass isotopomer abundances were determined by electrospray ionization-magnetic sector-mass spectrometry after in vivo administration of [(2)H(3)]leucine. Myosin heavy chain was also isolated and hydrolyzed to free amino acids. Muscle tRNA-amino acids were well labeled, by direct measurement. Enrichments of M(+1) and M(+2) mass isotopomers in the CK-peptide were measurable but low (consistent with a CK half-life of 3-10 days). Incorporation into skeletal muscle myosin indicated a half-life of 54 days. In conclusion, the general strategy of measuring protein kinetics by quantifying mass isotopomer abundances of mid-sized peptides from protein hydrolysates is effective, but CK does not turn over rapidly in muscle, contrary to previous reports. Identification of a rapid turnover muscle protein would be useful for this purpose.

Furosemide and 11beta-hydroxysteroid dehydrogenase activity, in man.

Mineralocorticoid receptors possess the same affinity for aldosterone and for cortisol and preferential binding of aldosterone is modulated by the 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) enzyme, which converts cortisol to its inactive metabolite cortisone. Several endogenous or exogenous compounds able to inhibit the enzyme have been described and, as a consequence, produce the syndrome of apparent mineralocorticoid excess (AME) characterized by hypertension, hypokalemia, volume repletion and suppression of the renin-angiotensin-aldosterone system. High doses of furosemide, a diuretic that works in the luminal surface of the thick ascending limb of Henle's loop, have been reported to inhibit 11 beta-OHSD activity to the same extent as licorice in vivo and in vitro, in rat. The aim of our study was to verify the effect of the drug on 11 beta-OHSD activity in man at the doses currently used in clinical practice. We tested the activity of 11 beta-OHSD following both acute and protracted administration of furosemide. In the acute study, the drug was administered at low (40 mg i.v. in bolo) and high doses (infusion of 10 mg/kg bw i.v for six hours); the protracted furosemide administration consisted in 50 mg/day for 20 days, by mouth. The ratios between the cortisol metabolites tetrahydrocortisol plus allo-tetrahydrocortisol to tetra-hydrocortisone and urinary free cortisol to urinary free cortisone were used to measure the activity of 11 beta-OHSD. Urinary cortisol, cortisone and their metabolites were tested by a gas-chromatographic/mass spectrometric method. Neither acute nor prolonged administration of furosemide did affect the activity of 11 beta-OHSD although the drug was able to modify plasma aldosterone and PRA secretion and to determine hypokalemia. Our results suggest that furosemide does not play a significant role in 11 beta-OHSD modulation in humans, at least at the dosage used in clinical practice.

[Dehydroepiandrosterone metabolism by Epidermophyton floccosum]. / Metabolismus von Dehydroepiandrosteron durch Epidermophyton floccosum.

Steroid hormones may be relevant for the fungus-host relation in dermatophytoses. In contrast to most other hosts of dermatophytes, humans are characterized by a high cutaneous concentration of the adrenal androgen dehydroepiandrosterone (DHEA) and its sulphate (DHEAS). To investigate whether the strictly anthropophilic dermatophyte Epidermophyton floccosum can metabolize this steroid hormone, cultures of E. floccosum were supplemented with DHEA. After 5 days of incubation the steroids in the culture supernatants were extracted and differentiated by gaschromatography and massspectrometry (GC-MS). The results show that a nearly complete metabolization of DHEA by E. floccosum leads to the formation of multiple new steroids/metabolites some of which have not been reported before. Therefore, this fungus could possibly mediate the hormone regulated cutaneous defense mechanisms of the host by an intraepidermal metabolization of DHEA.

Synthesis of ring B unsaturated estriols. Confirming the structure of a diagnostic analyte for Smith-Lemli-Opitz syndrome.

[structure: see text] Brief partial syntheses are described for ring B unsaturated estriols, which are candidate metabolites diagnostic for Smith-Lemli-Opitz syndrome prenatally. These steroids are also likely metabolites of the Premarin preparation used in estrogen replacement therapy. Equilin (8) was converted in three steps to 7-dehydroestriol, which was isomerized to 8-dehydroestriol. The simplicity of the transformations belies the lability of these previously inaccessible metabolites and their synthetic precursors.

Expression and putative role of 11 beta-hydroxysteroid dehydrogenase isozymes within the human eye.

PURPOSE: The human eye is an important target tissue for steroid hormones, and glucocorticoids have been implicated in the pathogenesis of ocular disease, including glaucoma. In peripheral tissues, corticosteroid hormone action is regulated at a prereceptor level through the activity of the 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) isozymes: an oxo-reductase (11 beta-HSD1) that activates cortisol (F) from cortisone (E) and a dehydrogenase (11 beta-HSD2) that inactivates F to E. The purpose of this study was to analyze the expression and putative role of 11 beta-HSD within the human eye. METHODS: Immunohistochemical and reverse transcription-polymerase chain reaction (RT-PCR) studies were performed on sections of human ocular tissues, surgical trabecular meshwork (TM) specimens and a ciliary nonpigmented epithelial (NPE) cell-line. Free F and E concentrations in aqueous humor were determined by gas chromatography-mass spectrometry (GC/MS). IOP was measured in eight male volunteers before and after oral ingestion of carbenoxolone (CBX), a known inhibitor of 11 beta-HSD. RESULTS: 11 beta-HSD1 was expressed in the basal cells of the corneal epithelium and the NPE. 11 beta-HSD2 was restricted to the corneal endothelium. RT-PCR revealed mRNA for only the glucocorticoid receptor (GR) in the TM specimens, whereas GR, mineralocorticoid receptor and 11 beta-HSD1 mRNAs were all present in the NPE cell line. The demonstration of free F in excess of E (F/E 14:1) in the aqueous humor suggested predominant 11 beta-HSD1 activity. Compared with baseline (14.7 +/- 1.06 mm Hg, mean +/- SD), the IOP decreased significantly on both the third and seventh days of CBX ingestion (12.48 +/- 1.11 mm Hg, P < 0.0001 and 11.78 +/- 1.50 mm Hg, P < 0.0001, respectively). CONCLUSIONS: These results suggest that the 11 beta-HSD1 isozyme may modulate steroid-regulated sodium transport across the NPE, thereby influencing IOP.

Dehydro-oestriol and dehydropregnanetriol are candidate analytes for prenatal diagnosis of Smith-Lemli-Opitz syndrome.

Gas chromatographic/mass spectrometric (GC/MS) analysis of maternal urine and serum steroids from 13 pregnancies at 25% risk for Smith-Lemli-Opitz syndrome (SLOS) was undertaken. All patients were between 12 and 31 weeks' gestational age. From dehydrocholesterol/cholesterol ratios determined in amniotic fluid and chorionic villus cells, five patients were shown to carry SLOS affected fetuses and eight patients were negative for the condition. Because it had previously been shown that dehydro-oestriol and dehydropregnanetriol were novel steroids produced in SLOS, these compounds were measured in the serum and urine samples of the 13 mothers. All five urine samples from SLOS affected pregnancies had high levels of both dehydrosteroid metabolites, which were below the detection limit in the non-affected pregnancies. The ratios of dehydro-oestriol/oestriol (DHE(3)/E(3)) were between 0.073 and 1.42 for the affected patients and less than 0.01 for unaffected patients. Corresponding values for dehydropregnanetriol/pregnanetriol (DHPT/PT) were 0.037-1.02 for affected and less than 0.01 for unaffected. In the positive serum sample available for analysis, the DHE(3)/E(3) ratio was 0.20 [unaffected (n=5), <0.014]. It is proposed that the measurement of DHE(3) and DHPT in maternal urine and serum may allow non-invasive antenatal diagnosis of SLOS.

Congenital deficiency of 11beta-hydroxysteroid dehydrogenase (apparent mineralocorticoid excess syndrome): diagnostic value of urinary free cortisol and cortisone.

The syndrome of apparent mineralocorticoid excess (AME) is an inherited form of hypertension. This disorder results from an inability of the enzyme 11beta-hydroxysteroid dehydrogenase (11beta-OHSD) to inactivate cortisol to cortisone. The diagnosis of AME is usually based on an elevated ratio of cortisol to cortisone reduced metabolites in the urine [tetrahydrocortisol plus allotetrahydrocortisol to tetrahydrocortisone (THF+alloTHF/THE)]. The principal site of "A" ring reduction is the liver, but AME arises from mutation in the gene encoding 11beta-OHSD2 in the kidney. We used a gas chromatographic/mass spectrometric method to measure the urinary free cortisol (UFF) and free cortisone (UFE) in 24 patients affected by the two variants of AME [19 with the classical form (type I) and 5 with the mild form called AME type II] in order to provide a more reproducible in vivo measure of the renal enzymatic activity. Type I patients were divided into two groups: children under 12 and adults. UFF levels (microg/24 h) did not differ between under-12 controls and AME type I children (mean+/-SD, 9+/-4 and 15+/-12, respectively), but was significantly higher in affected adults compared to controls: (62+/-32 vs 29+/-8, p<0.01). No differences were found between adult controls and AME type II patients (29+/-8 and 37.0+/-14, respectively). UFE was undetectable in 63% of AME type I and significantly lower in AME type II (p<0.05). As a consequence UFF/UFE ratio was significantly higher in AME type I patients both in children and adults compared to controls (AME children: 5.1+/-2.6; normal children: 0.43+/-0.2, p<0.01; AME type I adults: 17.7+/-19.6; normal adults: 0.54+/-0.3 p<0.01). For AME type II, where UFE was detectable in every case, the UFF/UFE ratio was significantly higher than adult controls (2.75+/-1.5 vs 0.54+/-0.3, p<0.01). In conclusion, our study indicates that UFE and UFF/UFE ratio are sensitive markers of 11beta-OHSD2, directly reflecting the activity of the renal isozyme and readily identifying patients with AME. The presence of an altered UFF/UFE ratio in both types of AME, although with different degree of severity, calls for re-evaluation and the classification of AME as a single disorder.

Prostate formation in a marsupial is mediated by the testicular androgen 5 alpha-androstane-3 alpha,17 beta-diol.

Development of the male urogenital tract in mammals is mediated by testicular androgens. It has been tacitly assumed that testosterone acts through its intracellular metabolite dihydrotestosterone (DHT) to mediate this process, but levels of these androgens are not sexually dimorphic in plasma at the time of prostate development. Here we show that the 3 alpha-reduced derivative of DHT, 5 alpha-androstane-3 alpha,17 beta-diol (5 alpha-adiol), is formed in testes of tammar wallaby pouch young and is higher in male than in female plasma in this species during early sexual differentiation. Administration of 5 alpha-adiol caused formation of prostatic buds in female wallaby pouch young, and in tissue minces of urogenital sinus and urogenital tubercle radioactive 5 alpha-adiol was converted to DHT, suggesting that circulating 5 alpha-adiol acts through DHT in target tissues. We conclude that circulating 5 alpha-adiol is a key hormone in male development.

Does kidney transplantation normalise cortisol metabolism in apparent mineralocorticoid excess syndrome?

The syndrome of apparent mineralocorticoid syndrome (AME) results from defective 11beta-hydroxysteroid dehydrogenase 2 (11beta-HSD2). This enzyme is co-expressed with the mineralocorticoid receptor (MR) in the kidney and converts cortisol to its inactive metabolite cortisone. Its deficiency allows the unmetabolized cortisol to bind to the MR inducing sodium retention, suppression of PRA and hypertension. Thus, the syndrome is a disorder of the kidney. We present here the first patient affected by AME cured by kidney transplantation. Formerly, she was considered to have a mild form of the syndrome (Type II), but progressively she developed renal failure which required dialysis and subsequent kidney transplantation. To test the ability of the transplanted kidney to normalise the patient's cortisol metabolism, we gave, in two different experiments, 25 and 50 mg/day of cortisone acetate or 15 and 30 mg/day of cortisol after inhibition of the endogenous cortisol by synthetic glucocorticoid (methylprednisolone and dexamethasone). The AME diagnostic urinary steroid ratios tetrahydrocortisol+5alphatetrahydrocortisol/tetrahydrocortisone and cortisol/cortisone were measured by gas chromatography/mass spectrometry. Transplantation resulted in lowering blood pressure and in normalization of serum K and PRA. After administration of a physiological dose of cortisol (15 mg/day), the urinary free cortisol/cortisone ratio was corrected (in contrast to the A-ring reduced metabolites ratio), confirming that the new kidney had functional 11beta-HSD2. This ratio was abnormally high when the supra-physiological dose of cortisol 30 mg/day was given. After cortisone administration, the tetrahydrocortisol+5alphatetrahydrocortisol/tetrahydrocortisone ratio resulted normalised with both physiological and supra-physiological doses, confirming that the hepatic reductase activity is not affected. As expected, the urinary free cortisol/cortisone ratio was normal with physiological, but increased after supra-physiological doses of cortisone. The described case indicates a normalisation of cortisol metabolism after kidney transplantation in AME patient and confirms the supposed pathophysiology of the syndrome. Moreover, it suggests a new therapeutic strategy in particularly vulnerable cohorts of patients inadequately responsive to drug therapy or with kidney failure.

Apparent cortisone reductase deficiency: a rare cause of hyperandrogenemia and hypercortisolism.

A 55-year-old woman presented with androgenetic alopecia which had started at age 40. Her clinical history revealed that, unlike her younger sister, she was unable to conceive and was diagnosed as being sterile at age 30. At age 45, 21-hydroxylase deficiency (late-onset CAH) was assumed and glucocorticoid treatment suggested, but not initiated. There was slight hirsutism, but no other sign of virilization. Retesting of plasma steroids revealed elevated 17-OH-progesterone and free testosterone. Treatment with prednisone, cyproterone acetate, and spironolactone was started with significant clinical success. Surprisingly, the analyses of urinary steroid metabolites revealed a pattern that did not support the diagnosis of 21-hydroxylase deficiency (pregnanetriolone absent, pregnanediol, 17-OH-pregnanolone and pregnanetriol not increased). Abdominal CT showed bilateral adrenal hyperplasia and masses in both ovaries. Bilateral adnexectomy was performed, and cystic teratomas were diagnosed. Postoperative urinary steroid analyses showed a decreased tetrahydrocortisol/tetrahydrocortisone ratio (values around 0.08 as compared to age- and sex-matched controls with a ratio of about 0.5-0.8). Plasma cortisol appeared to be repeatedly elevated with exogenous sources excluded. Mass spectrometry showed that, while the tetrahydro metabolites were mainly cortisone-derived, the metabolites not reduced in A ring were mostly cortisol derivatives. This constellation clearly indicates cortisone reductase deficiency, a defect of hepatic 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD1). This enzyme catalyzes the oxidation of cortisol to cortisone and the reduction of cortisone to cortisol. In contrast to the corresponding kidney enzyme (11 beta-HSD2), its primary activity is, however, reductive. Although this is only the fifth reported case of that defect, more attention should be paid to this condition in hyperandrogenic women, even if elevated 17-OH-progesterone and testosterone suggest a more frequent cause.

Midgestational maternal urine steroid markers of fetal Smith-Lemli-Opitz (SLO) syndrome (7-dehydrocholesterol 7-reductase deficiency).

Smith-Lemli-Opitz syndrome (SLOS) is a malformation syndrome associated with 7-dehydrocholesterol (7DHC) 7-reductase deficiency. Although SLOS can be detected in an affected fetus before midpregnancy by measurement of 7DHC levels in amniotic fluid or chorionic villus cells, a noninvasive, more routine method is needed. Accordingly, this study was instigated to search for specific steroids in maternal urine in an affected pregnancy that reflect the 7-reductase deficiency of the fetus, ie, steroids retaining 7,8-unsaturation. Steroids were characterized by gas chromatography/mass spectrometry after urinary extraction, conjugate separation, and derivatization. Most steroids in maternal urine from a patient carrying a SLOS fetus were identified as progesterone metabolites, and these were entirely conventional, showing no evidence of additional unsaturation. Unsaturated homologues of the cortisol metabolites were also not detected. However, unsaturated homologues of pregnane-3,16,20-triols and pregnane-3,17,20-triol were found. Most likely, these are 7,8-unsaturated homologues, but 8,9-unsaturation is also possible because of the known activity of delta7-delta8-isomerase on 7DHC, which results in 8DHC being a prominent sterol in SLOS. Among these novel human steroids, the following were provisionally characterized: 5beta-pregn-7(or 8)-ene-3alpha,17alpha,20alpha-triol, 5beta-pregn-7(or 8)-ene-3alpha,16alpha,20alpha-triol, and 5alpha-pregn-7(or 8)-ene-3,16alpha,20alpha-triol. Confirmation of the position of unsaturation will require steroid synthesis. These novel steroids are not present in normal pregnancy urine and, therefore, are valuable for prenatal diagnosis of SLOS. In addition, separate studies have shown that 5beta-pregn-7(or 8)-ene-3alpha,17alpha,20alpha-triol is present in urine of children and adults with SLOS, and so is a useful analyte for confirmation of the disorder throughout life.

Neonatal urinary steroids in Smith-Lemli-Opitz syndrome associated with 7-dehydrocholesterol reductase deficiency.

The biosynthetic abnormality in Smith-Lemli-Opitz syndrome (SLOS) is a deficiency of 7-dehydrocholesterol (7DHC) reductase, the enzyme responsible for catalyzing the final step in the Kandutsch-Russell pathway for cholesterol synthesis. Because the disposition of 7DHC and 8-dehydrocholesterol [8DHC; cholesta-5,8(9)-dien-3beta-ol] produced in this syndrome is little understood, we have analyzed urine from three young infants by gas chromatography/mass spectrometry to characterize its steroid metabolites. All steroid metabolites of adrenal origin found in normal infant urine were also found in urine from the patients with SLOS but in reduced amount. Quantitatively, the major steroids in these SLOS patients were identified by mass spectrometry as homologs of normal neonatal steroids possessing an additional double bond. Generally, two forms of each steroid were present in a similar amount. Because of the markedly increased levels of 7DHC and 8DHC in SLOS, these almost certainly represented the 5,7 and 5,8(9) unsaturated forms of each metabolite. The most abundant steroids were tentatively identified as 3beta,16alpha-dihydroxy-5,7-pregnadien-20-one and 3beta,16alpha-dihydroxy-5,8(9)-pregnadien-20-one, although similar 21-hydroxylated steroids and homologs of 16alpha-hydroxy-DHEA were also found. This study shows that all enzymatic steps used by cholesterol in the DHEA synthetic pathway are also functional for 7DHC and 8DHC.

Cortisol metabolism in human obesity: impaired cortisone-->cortisol conversion in subjects with central adiposity.

For a given body mass index (BMI), mortality is higher in patients with central compared to generalized obesity. Glucocorticoids play an important role in determining body fat distribution, but circulating cortisol concentrations are reported to be normal in obese patients. Our recent studies show enhanced conversion of inactive cortisone (E) to active cortisol (F) through the expression of 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) in cultured omental adipose stromal cells; the autocrine production of F may be a crucial factor in the pathogenesis of central obesity. We have now analyzed F metabolism in subjects with BMIs between 20-25 kg/m2 (group A), 25-30 kg/m2 (group B), and more than 30 kg/m2 (group C; n 12 in each group; six males and six premenopausal females; aged 23-44 yr). Glucose/insulin were measured using a 75-g oral glucose tolerance test, and each subject had total body and regional fat (scapular, waist, hip, and thigh) quantified using dual energy x-ray absorptiometry. Urinary total F metabolites (measured by gas chromatography/mass spectrometry) were increased in subjects with obesity [group A, 11,176 +/- 1,530 microg/24 h (mean +/- SE); group C, 13,661 +/- 1,444], although not significantly so (P = 0.08). There was a significant reduction in the urinary tetrahydrocortisol (THF) +/- 5alpha-THF/tetrahydrocortisone (THE) and the cortol/cortolone ratio in obesity (group A vs. C, 1.06 +/- 0.08 vs. 0.84 +/- 0.04 and 0.41 +/- 0.03 vs. 0.34 +/- 0.03, respectively; both P < 0.05). Urinary free F (UFF) excretion was similar in all three groups, as was the UFF/urinary free E (UFE) ratio. The 0900 h circulating F, E, and ACTH pre- and postovernight 1-mg dexamethasone suppression values were similar in all three groups, but a reduction in the generation of serum F from dexamethasone-suppressed values after oral cortisone acetate (25 mg) was evident in both obese groups [e.g. 546 +/- 37 nmol/L in group A vs. 412 +/- 40 in group B (P < 0.05) and 388 +/- 38 in group C (P < 0.01) 180 min post-E]. Insulin resistance was present in groups B and C, but regression analysis revealed no relationship between F metabolites or the THF +/- 5alpha-THF/THE ratio and insulin action (homeostasis model assessment analysis and insulin values in the oral glucose tolerance test). There was, however, a highly significant relationship between the THF +/- 5alpha-THF/THE ratio and BMI (t = -3.44; P < 0.01) and total body fat (t = -2.27; P < 0.05). Stepwise regression analyses indicated an inverse relationship between THF+/-5alpha-THF/THE and scapular and waist fat (t = -2.25; P = 0.03) and a direct relationship with hip and thigh fat (t = 2.42; P = 0.02) in both sexes. The fall in the THF + 5alpha-THF/THE ratio but unchanged UFF/UFE ratio together with impaired F concentrations after oral E indicates inhibition of 11betaHSD1 in subjects with obesity. This results in an increased MCR for F, explaining the increased F secretion rate in obesity in the face of normal circulating F concentrations. 11BetaHSD1 activity is highly related to body fat distribution, with android or central obesity, but not gynoid obesity, associated with reduced activity in both sexes. This reduction in 11betaHSD1 activity raises new questions as to the primary role of 11betaHSD1 in the pathogenesis of insulin resistance and central obesity.

Equine type estrogens produced by a pregnant woman carrying a Smith-Lemli-Opitz syndrome fetus.

The equine-type estriols 1,3,5(10),7-estratetraene-3,16alpha,17beta-triol (16alpha-hydroxy-17beta-dihydroequilin) and 1,3,5(10),6,8-estrapentaene-3,16alpha,17beta-triol (16alpha-hydroxy-17beta-dihydroequilenin) constituted over half of the estrogens excreted by a woman carrying a Smith-Lemli-Opitz syndrome (SLOS) affected fetus. The steroids were characterized by gas chromatography-mass spectrometry (GC/MS), and mass spectra of the dehydro estriols as trimethylsilyl ethers are illustrated. SLOS is associated with 7-dehydrocholesterol (7DHC), delta 7-reductase deficiency; the enzyme catalyzing the final step in cholesterol biosynthesis. Identification of these equine estrogens show that an estrogen biosynthetic pathway parallel to normal is functional in the feto-placental unit and uses 7DHC as precursor, therefore P450scc, P450c17, and 3betaHSD and P450arom are all active on 7-dehydrometabolites. Patients with affected fetuses have low plasma estriol values (probably due to deficient production of the cholesterol precursor) and this is often a warning sign which instigates further evaluation for SLOS. The estriol deficiency is not quantitatively made up by the dehydrometabolites, and the combined excretion was found to be about one-third of the mean of gestational age matched controls. The importance of these findings lies in the potential value of dehydroestriol measurement for non-invasive diagnosis of SLOS at mid-gestation. Currently diagnosis relies on imaging, since SLOS is a malformation syndrome, and measurement of 7DHC levels in amniotic fluid and chorionic villus tissue.