Endocrine Abstracts

Iodothyronamines are endogenous trace amines which are putative products of thyroid hormone decarboxylation by Aromatic Amino acid Decarboxylase (AADC). 3-Iodothyronamine (T1AM) has been shown to have profound effects on rodents in vivo, including reductions in body temperature, blood pressure and cardiac output, alongside a switch from carbohydrate to fat utilisation. It is possible that T1AM induces some of these effec...

Methyl oxime–trimethylsilyl (MO-TMS) derivatisation with gas chromatography–mass spectrometric (GC-MS) analysis has been well established in the analysis of glucocorticoids and is still used in many laboratories for profiling endogenous steroids for clinical purposes. There appears to be a clinical need to extend the analysis to xenobiotic glucocorticoids, primarily to elucidate cases of patients presenting with adverse symptoms associated with glucocorticoid excess,...

Although amyloid deposition can cause a goitre thyrotoxicosis secondary to amyloidosis is rare. We report a case of fatal systemic amyloidosis presenting as thyrotoxicosis.A 62-year-old previously healthy male presented with heat intolerance, weight loss and tremor. On examination he had moderate sized firm goitre and mild dysthyroid eye disease. Biochemistry confirmed thyrotoxicosis; serum free T4 47 pmol/l (normal 10–25) freeT3 14.4 pmol/l (normal...

Dairy cows normally calve for the first time when not yet fully grown. Subsequent pregnancies occur during lactation. Therefore in primiparous (PP) cows the fetus competes for nutrients with maternal growth, while in multiparous (MP) cows they compete with milk production. Human epidemiological studies demonstrate that low birth weight can predispose offspring to a variety of metabolic diseases in adult life. This study investigated the hypothesis that such competition limits ...

Introduction. Lipocortin-1 (annexin-1 and p35) is a 37-kDa Ca2+-dependant membrane-binding protein that hasanti-inflammatory, anti-mitotic and anti-proliferative properties.With these properties in mind it was hypothesised that lipocortin-1 may have an important role in the endometrium. Therefore, the aim ofthis study was to determine the distribution of lipocortin-1 in normal and abnormal endometrial tissue.Methods. Formalin fixed paraffin embedded sect...

Patients with acute intermittent porphyria (AIP) but not those with porphyria cutanea tarda (PCT) have a reported predominance in urine of 5 beta-reduced androgen metabolites over 5 alpha epimers. Steroids of 5 beta- androstane and pregnane types induce delta-aminolevulinic acid (ALA) synthase in chick embryos in vitro, so altered 5-reduction may predispose to attacks. We have comprehensively examined urine androgen and cortisol metabolites by gas-liquid chromatography and uri...

For investigation of mild glucocorticoid resistance, dexamethasone may be inappropriate because, unlike cortisol, it crosses the blood-brain barrier and suitably low doses are difficult to titrate. Prednisolone has been proposed as an alternative but assay of cortisol as an endpoint is subject to cross-reaction with prednisolone in most ligand assays. Using capillary gas chromatography, we can distinguish urinary cortisol and prednisolone metabolites. We have compared this app...

Acute cortisol increase in man, whether from endogenous or exogenous sources, is associated with changes in cortisol:cortisone equilibrium. We have examined these during normal daily circadian rhythms and following treatment with hydrocortisone. Following local ethical committee approval, four adult volunteers (2 male) collected urine samples over 3 hour periods starting from midnight and over hourly periods between 0600 & 0900 to define the morning cortisol peak. They pro...

The adrenal cortex is the primary site of steroid synthesis, producing glucocorticoids under the control of the hypothalamic–pituitary axis and mineralocorticoids under the control of the renin–angiotensin system.Adrenal insufficiency, which can be life threatening, is cause by a number of adrenal disorders, and lifelong management of these patients with exogenous steroids can be challenging. No drug suitably mimics the diurnal pattern of corti...

Steroids present in human serum can be used to identify a number of conditions such as congenital adrenal hyperplasia, Addison’s disease and Cushing’s disorder. Historically this has been completed using immunoassays; currently there is a move towards mass spectrometry which reduces analysis time, cross reactivity and improves sensitivity. When mass spectrometers are coupled with liquid chromatography systems (LC–MS) it is possible to monitor a number of steroid...