Endocrine Abstracts

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...

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...

Scattered case reports have described patients who have been diagnosed with both primary hyperaldosteronism and prolactinoma. Prolactin receptor (PRLR) is known to be expressed in human adrenal cortex. Furthermore, PRLR mRNA and protein have both been detected in human adrenal tumors. It has also been shown that PRL treatment of adrenal cells is capable of stimulating aldosterone secretion. The contribution of PRL to the development of hyperaldosteronism is u...

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...

Poor agreement between different analytical methods measuring aldosterone concentrations impedes applicability of uniform cut-offs in the diagnostic work-up of primary aldosteronism (PA). We compared 4 analytical methods (2 immunoassays and 2 LC-MS/MS) in plasma samples before and after saline infusion test (SIT). 80 hypertensive patients underwent the standardized diagnostic work-up within the German Conn’s registry. Patients (PA n=39/non-PA n=41) were ...

Low-carbohydrate/high-fat diets (LC–HFD) are a popular way of dieting among the general population as several reports in humans indicate that LC–HFD induce weight loss in overweight subjects without caloric restriction and may improve glucose metabolism. However, regarding this type of diet there is also much controversy in scientific literature because clinical studies and data from animal experiments suggest severe side effects and thus warrant caution. Furthermore...

Measuring circulating concentrations of GH and insulin-like growth factor (IGF1) is crucial to biochemically establish the diagnosis of GH-related disorders such as acromegaly and GH deficiency. Many commercial or in-house immunoassays are in use. Controlled studies and regular external quality assessment schemes document considerable disparities in GH and IGF1 concentrations reported when different assays are used. Among the reasons for the differences are the molecular heter...

Recombinant human growth hormone (rhGH) is abused as a performance enhancing drug, but our knowledge about this is mainly based on rumours, confessions of former athletes and on actions of the police. For many years, the detection of rhGH application by biochemical methods was thought to be impossible. Physiological and biochemical properties of hGH made the development of a test method difficult. rhGH is identical in amino acid sequence and chemical properties to the main, 22...