Searchable abstracts of presentations at key conferences in endocrinology

ea0077p8 | Adrenal and Cardiovascular | SFEBES2021

Comparative steroid profiling in large animals

Morgan Ruth , Denham Scott , Lee Patricia , Homer Natalie

Large animals are increasingly used a models for endocrine research. Unlike rodents they are cortisol-dominant and thus more similar to humans. In this study we use two novel analytical methods to compare the steroid profile of pigs, sheep and humans; 1. Simultaneous quantification of primary glucocorticoids, glucocorticoid precursors and mineralocorticoids in plasma (>20 steroids); 2.Quantification of glucocorticoids metabolites (>10 ...

ea0025p308 | Steroids | SFEBES2011

Derivatisation of estrogens enhances sensitivity of analysis by liquid chromatography tandem mass spectrometry

Homer Natalie , Cobice Diego , Gibb Fraser , Naredo Gregorio , Denham Scott , Walker Brian , Andrew Ruth

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...

ea0021p339 | Steroids | SFEBES2009

Analysis of cortisol by stable isotope dilution liquid chromatography–tandem mass spectrometry (LC–MS/MS): pitfalls of rapid LC–MS/MS analysis of clinical samples

Homer Natalie , Denham Scott , Stimson Roland , Watson David , Walker Brian , Andrew Ruth

The glucocorticoid hormone, cortisol, regulates fuel metabolism, inflammation and stress–responses. Its circulating concentrations are tightly controlled by the hypothalamic–pituitary–adrenal axis. However, 11β-hydroxysteroid dehydrogenase 1 (11βHSD1) generates additional cortisol in tissues, by reduction of inert cortisone. Using a tracer (9,11,12,12[2H]4-cortisol; d4-cortisol), the velocity of 11βHSD1 can be determined as t...

ea0073oc15.1 | Oral Communications 15: Late Breaking | ECE2021

Differential steroidomic profiles of human visceral and subcutaneous adipose tissue before and after bariatric surgery-induced weight loss

Laforest Sofia , Denham Scott , Denver Nina , Biertho Laurent , Homer Natalie Z.M. , Andrew Ruth , Tchernof Andre

BackgroundObesity is closely associated with impaired adipose tissue function. Although bariatric surgery is the treatment of choice for severe obesity and its related conditions, there are conflicting data on the reversal of adipose tissue dysfunction after surgery-induced weight loss. We hypothesise that local steroid hormone availability influences fat deposition or mobilisation and that these changes track with weight loss improvements, because plasm...

ea0065p365 | Reproductive Endocrinology and Biology | SFEBES2019

Derivatisation of 5α-dihydrotestosterone enhances sensitivity of analysis of human plasma by liquid chromatography tandem mass spectrometry

Faqehi Abdullah , Denham Scott , Naredo-Gonzalezb Gregorio , Cobice Diego , Sabil Ghazali , Upreti Rita , Gibb Fraser , Homer Natalie , Andrew Ruth

Liquid Chromatography tandem mass spectrometry (LC–MS/MS) is gold-standard for androgen analysis in biological fluids, superseding immunoassays in specificity, particularly at low concentrations. While LC–MS/MS is well established for analysis of testosterone (T) and androstenedione (A4), 5α-dihydrotestosterone (DHT) presents greater analytical challenges. DHT circulates at low nanomolar concentrations in men and lower in women, ionising inefficiently. Thus, eve...

ea0077lb57 | Late Breaking | SFEBES2021

A Novel LC-MS/MS Method for the Simultaneous Detection of Multiple Steroids in Plasma and Tissue Lysates, used to verify Cell Autonomous Sex Identity in birds

Denham Scott , Betterton Victoria , Ioannidis Jason , Lee Patricia , Zhao Debiao , Simpson Joanna , Caughey Sarah , Dunn Ian , Clinton Mike , Wilson Peter , Homer Natalie

Cell autonomous sex identity (CASI) of birds is the concept that sex-steroids have little or no effect on the development of secondary sexual characteristics in birds, and that sexual dimorphisms are determined by the sex-chromosome content of cells in individual tissues. In avian species males have a ZZ sex chromosome, while females are ZW. Sexual dimorphisms in chickens, such as muscle mass, comb and wattle size and hackles and spur development are believed to be determined ...