Endocrine Abstracts

Canrenone and mifepristone (RU486) are respectively mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) antagonists commonly used to block or displace steroid for clinical pharmacological or research purposes. The aim of this study was to develop and validate a sensitive, quantitative assay for the combined analysis of glucocorticoids (cortisol, cortisone, corticosterone, and 11-dehydrocorticosterone), mineralocorticoids (aldosterone), canrenoate, and mifepristone...

Background: 5α-Reductase (5αR) catalyses conversion of testosterone to its more potent metabolite dihydrotestosterone (DHT) and is inhibited when treating benign prostatic hyperplasia. 5αR has two isozymes; dual isozyme inhibition with dutasteride gives greater DHT suppression than finasteride, which inhibits only 5αR type 2.Aim: To develop a novel assay to simultaneously analyse testosterone, epitestosterone, DHT, androstenedione, du...

Circulating estrogens decrease after the menopause from 60–400 to 5–30 pg/ml in postmenopausal women and in men are below 30 pg/ml. These low physiological concentrations present an analytical challenge. Analysis of steroids by tandem mass spectrometry is attractive due to its high specificity compared with immunoassays. However, estrogens do not ionise efficiently and therefore chemical modifications are necessary to achieve the sensitivity required.<p class="ab...

Physiological circulating concentrations of estrogens are very low in men and postmenopausal women (<50 pg/ml), which presenting analytical challenges. Immunoassays can detect as low as 30 pg/ml, but cross-reactivity is a concern. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) offers greater specificity than immunoassays, but ionisation of estrogens is inefficient. Derivatisation, which introduces charged moieties, may enhance ionisation. Dansylated de...