Endocrine Abstracts

The purpose of our study was to establish an assay for the measurement of aldosterone in saliva which utilises a simple, non-invasive sampling technique on an out-patient basis. For this we have developed a non-isotopic, time-resolved fluorescence immunoassay. The assay only requires a volume of 100 μl for each duplicate value obtained and involves an overnight incubation after extraction of samples. Cross-reactivity with potentially interfering steroids is below 0.01%. T...

Aldosterone is synthesized acutely upon stimulation of the renin-angiotensin-aldosterone system from the cells of the zona glomerulosa. Several enzymes are involved in this steroidogenic process including the steroidogenic acute regulatory protein (StAR), P450 side chain cleavage enzyme (Cyp11a1) and aldosterone synthase, the product of the gene Cyp11b2.We investigated the short time transcriptional regulation of these genes in wild type mi...

Mice overexpressing growth hormone (GH) have about two-fold higher IGF-I and clear increases in body and organ weights. Moreover, administration of GH to hypophysectomised or dwarf mice has been shown to increase IGF-I. Data on the short term effects of exogenous administration of rhGH in normal rodents remain scarce.Therefore, we measured IGF-I before and after one week of GH-treatment in 10-week-old female mice, injected daily with two different doses ...

Background: Identifying hypertensive patients with primary aldosteronism (PA) using the aldosterone to renin ratio (ARR) is crucial for optimizing their treatment. Various medications used to treat hypertension are known to alter levels of aldosterone and renin, thus affecting the ARR. As withdrawing all medication before screening is often unrealistic, we aimed to determine the degree of interference of some commonly used agents on the ARR using assays on the automated IDS-iS...

Background: Screening for primary aldosteronism (PA) using the aldosterone to renin ratio (ARR) is recommended by clinical practice guidelines in patient groups with a high prevalence as the disease is reported by several authors in more than 10% of essential hypertensives (EH).Methods: Plasma aldosterone concentration (PAC) and direct renin (DR) were measured using two novel automated chemiluminescence assays (IDS-iSYS; Boldon, UK) and compared to the S...

Differential diagnosis between bilateral adrenal hyperplasia (BAH) and aldosterone producing adenoma (APA) in aldosteronism remains challenging in many cases due to the high prevalence of incidentalomas during imaging techniques, the limited sensitivity of orthostatic testing and the technical difficulties of adrenal vein sampling (AVS).We investigated circadian variation in salivary aldosterone (SA) in patients with APA (n=22) and BAH (n=2...

Although primary aldosteronism (PA) is considered to be the most prevalent cause of secondary hypertension the underlying genetic mechanisms have been elucidated only for the rare familial forms of the disease. In an attempt to define novel genetic loci involved in the pathophysiology of PA a phenotype-driven mutagenesis screening after treatment with the alkylating agent N-ethyl-N-nitrosourea was established for the parameter aldosterone. The aldosterone values ...

According to recent studies, primary aldosteronism is considered to be responsible for almost 10% of all cases of arterial hypertension. The genetic background of this common disease, however, has been elucidated only for the rare familial types whereas in the large majority of sporadic cases it still remains unclear. In an attempt to define novel genetic mechanisms of hyperaldosteronism we utilized a random mutagenesis screen after treatment with the alkylating agent N...

Background: Adipose tissue blood flow (ATBF) is important for delivering nutrients and oxygen to adipose tissue (AT), and distributing adipokines and metabolites into the circulation. ATBF has been measured with the 133Xenon wash-out technique (gold standard), microdialysis, laser Doppler Fluximetry, and contrast-enhanced ultrasound. However, due to decline in world-wide 133Xenon production and the invasive nature of other techniques, an alternative metho...

Background: Glucocorticoids have pleiotropic metabolic functions and acute glucocorticoid excess causes dramatic disruption of human metabolism. Whether glucocorticoids exert adipose tissue depot-specific effects on the nontargeted metabolome in unknown.Aim: Assess the nontargeted metabolome in the systemic circulation and in femoral adipose tissue-specific blood samples in response to physiological hyperinsulinaemia and acute hypercortisolaemia.<p c...