Endocrine Abstracts

Objectives: Oestrogen analysis using liquid chromatography mass spectrometry is problematic, as oestrogens do not readily ionise. This coupled with low concentrations in men, pre-pubertal and post-menopausal women provides an analytical challenge. We investigated N-Methyl Pyridine-3-sulfonyl chloride (NMPS) derivatisation, as described by Wang et al. (Steroids 2015 Apr;96:140-152) to improve sensitivity of 11 oestrogens; oestrone (E1), oestradiol (E2), 2-hydroxy-oestr...

Mass spectrometry has been used to measure steroids for more than 40 years, but has gained popularity within the endocrine field in the last 15+ years. This is mainly due to technological advances that facilitated the development of high throughput methods.Historically, steroids were measured by crude techniques such as thin layer chromatography (TLC) and later by the more sophisticated RIA. The problems with these techniques include:<p class="abstex...

Context: Nicotinamide nucleotide transhydrogenase (NNT) is a NADPH-generating mitochondrial proton pump with a central role in mitochondrial antioxidant pathways. Recent studies revealed inactivating NNT mutations in patients with familial glucocorticoid deficiency, indicating a selective susceptibility of the adrenal cortex to NNT deficiency and oxidative stress. Here we explored the potential value of NNT as a therapeutic target in adrenocortical cancer.<p class="abstext...

Context: Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder in women of classic androgen synthesis. Recent work has highlighted that impaired DHEA sulfation results in enhanced androgen production. Here, we evaluated the relationship between DHEA and DHEAS and androgen excess and metabolic phenotype in PCOS.Patients and methods: We compared 65 women with PCOS to 35 healthy women matched for age and body mass index (BMI). All subject...

Background: Cushing’s syndrome (CS) is caused by endogenous cortisol excess and is associated with significant morbidity. Twenty-four-hour urinary cortisol is one of the most useful tools to diagnose CS although it has limitations, especially in “mild” and “subclinical” forms of cortisol excess. We hypothesized that given the diurnal rhythm of physiological cortisol secretion, night-time urinary glucocorticoid excretion should be lower than day-time ex...

Steroid hormones are important regulators of many physiological processes. The steroid precursor pregnenolone is converted through several enzymatic steps into all types of steroids, including the stress hormone cortisol. Mitochondrial steroidogenic cytochrome P450 (CYP) enzymes crucially relying on electron transfer from the redox partner ferredoxin (FDX1) are involved in key steps of the cortisol biosynthesis pathway.Cortisol is well-known regulator of...

Introduction: Prostate cancer (PC) is dependent on androgen receptor (AR) activation by its canonical ligands testosterone and 5α-dihydrotestosterone (DHT). Intratumoural androgens persisting after castration give rise to castration-resistant PC (CRPC). These intraprostatic androgen levels are hypothesized to result from either adrenal androgen conversion or intratumoural de novo DHT synthesis through the classic or alternative pathways. Quantifying the steroid f...

Context: Androgen excess, obesity and hyperinsulinaemia are the cardinal features of polycystic ovarian syndrome (PCOS). While several studies have addressed the relationship between androgen excess and hyperinsulinaemia, the link between androgen excess and fat distribution remains largely undefined. Recent work has highlighted the importance of adipose tissue as an organ of androgen activation. Here, we evaluated the relationship between visceral fat and androgen excess in w...

Background: Urinary steroid metabolite profiling is an accurate reflection of adrenal and gonadal steroid output and metabolism in peripheral target cells of steroid action. Measurement of steroid metabolite excretion by gas chromatography-–mass spectrometry (GC–MS) is considered reference standard for biochemical diagnosis of steroidogenic disorders. However, performance of GC–MS analysis and interpretation of the resulting data requires significant expertise a...

Recently, liquid chromatography–tandem mass spectrometry (LC–MS/MS) was stated to be the method of choice to measure sex steroids.1 Information on the mutual agreement of LC–MS/MS methods, however, is scarce. Therefore, we compared seven published LC–MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and DHEA. Fifty-five random serum samples obtained from volunteers were analysed in duplicate by seven published LC&#1...