Endocrine Abstracts

Liquid chromatography–tandem mass spectrometry (LC–MS/MS) is a powerful tool that is changing the way we analyse steroids in the clinical laboratory. It offers positive compound identification to enable the unequivocal identification of a compound free from interference. LC–MS/MS is already opening up the field of steroid analysis in endocrinology and is providing new applications for individual steroids and panels of steroids in different clinical conditions. L...

Introduction: Measurement of serum testosterone is necessary for the investigation of androgen disorders in males and females. Measurement of other androgens such as DHEAS and androstenedione (A4) may also be important in the investigation of PCOS and 17-hydroxyprogesterone (17-OHP) is useful to differentiate late onset CAH in patients with raised A4. Although it would be advantageous to measure all four steroids simultaneously this is not always easy because...

Introduction: The measurement of male androgens in most NHS laboratories is often limited to testosterone alone. To more accurately determine the androgen status in men the measurement of other androgens such as DHT and DHEA would be beneficial however these are difficult to measure without derivatisation. We report a combined LC–MS/MS assay for the measurement of testosterone, androstenendione, DHT and DHEA on a small sample volume.Methods: Zinc su...

Introduction: Most clinical laboratories use immunoassays to measure estradiol despite limitations such as poor specificity, poor sensitivity and wide variability between different manufacturers’ assays. LC–MS/MS assays overcome the issues of sensitivity and specificity however the methods reported in the literature often involve complex sample preparation and lengthy run times. We describe a simple, rapid assay for the simultaneous measurement of serum estradiol and...

Background: Plasma metanephrine analysis is widely accepted as the test of choice for phaeochromocytomas and sympathetic extra-adrenal paragangliomas. It is important to analyse 3-methoxytyramine along with metanephrine and normetanephrine as 3-MT measurement has been shown to be useful in tumour localisation and also in determining whether metastasis has taken place. 3-MT analysis is challenging as the concentrations of 3MT of interest are very low, and the sensitivity of man...

Introduction: Testosterone measurement by liquid chromatography tandem mass spectrometry (LC-MS/MS) is well accepted as the preferred technique for the analysis of serum testosterone in both males and particularly females. However variation is seen between LC-MS/MS assays and is most likely to be due to method differences between laboratories. One area of inconsistency amongst routine LC-MS/MS assays is the choice of internal standard. We investigated the effects of three inte...

Introduction: Prednisolone is well known to interfere in routine immunoassays for cortisol with uncertainty surrounding the degree of this interference. Methods using tandem mass spectrometry technologies offer more specificity, however there have been some reports of prednisolone interference in mass spectrometry assays. We aimed to characterise the extent of prednisolone interference in both an automated immunoassay and a tandem mass spectrometry method (TMS).<p class="a...

Aim: The investigation of female androgen status in our laboratory is measured as a profile. Androstenedione, testosterone and DHEAS are analysed by liquid chromatography–tandem mass spectrometry. SHBG is analysed by immunoassay, and all results are reported simultaneously. The main aim was to investigate the management of patients who have a raised DHEAS level.Method: Ethical approval was granted for this study. Females with DHEAS levels >6.9 n...

Oxytocin is a peptide hormone consisting of 9 amino acids, with a mass of 1007 Da. It is synthesised in the hypothalamus and secreted from the posterior pituitary. It has well known roles in lactation and uterine contraction, however it is also thought to act within the brain to influence complex social behaviours such as bonding, empathy, and trust. Recently there has been increasing interest in the potential role of oxytocin in the pathophysiology...

Oxytocin is a peptide hormone consisting of 9 amino acids, with a mass of 1007 Da. It is synthesised in the hypothalamus and secreted from the posterior pituitary. It has well known roles in lactation and uterine contraction, however it is also thought to act within the brain to influence complex social behaviours such as bonding, empathy, and trust. Recently there has been increasing interest in the potential role of oxytocin in the pathophysiology...