Endocrine Abstracts

While it is generally acknowledged that hyperthyroidism and Paget's disease are states of increased bone turnover and that treatment reduces this, whether treatment entirely corrects or reverses abnormalities has not been established. A variety of biomarkers for bone formation which include serum levels of bone alkaline phosphatase (BAP), osteocalcin (OC) and amino terminal procollagen type 1N propeptide (PINP) and resorption biomarkers which include urinary excretion of deoxy...

The syndrome of inappropriate antidiuretic hormone (SIADH) is characterised by euvolamic hyponatraemia. Patients with SIADH continue to drink normal amounts of fluid, despite plasma osmolalities well below the physiological osmotic threshold for the onset of thirst. The regulation of thirst has not been previously studied in SIADH. We studied the characteristics of osmotically-stimulated thirst and vasopressin (AVP) secretion, and the non-osmotic suppression of thirst and AVP ...

Central cholinergic defects, as well as cognitive impairments, have been reported in humans with non-insulin-dependent diabetes mellitus (NIDDM). The levels of acetylcholine are partly controlled by the activity of acetylcholinesterase (AChE) which breaks it down. We have previously reported evidence for abnormal AChE activity in the skeletal muscles of the obese diabetic (ob/ob) mouse which provides a model for NIDDM. The aim of the present study was to investigate the levels...

The importance of the differentiation between the apparent benign clinical condition of macroprolactinaemia and that of true hyperprolactinaemia, which requires therapy, is becoming widely recognised. Laboratories routinely rely on prolactin recoveries of less than 40 percent following treatment of sera with polyethylene glycol (PEG) to distinguish between the former and latter conditions. However, the 40 percent threshold employed is arbitrarily defined with little scientific...

The central obese phenotype characteristic of Cushing's syndrome emphasises the role of glucocorticoids (GC) in regulating adipose tissue mass and distribution. We have shown that GCs stimulate adipocyte differentiation, but equally inhibit adipose stromal cell (ASC) proliferation. These effects are regulated at a pre-receptor level through 11beta-hydroxysteroid dehydrogenase type 1, but the 'post-receptor' signalling pathways remain unclear. To define novel GC targets in huma...

Lipid sensing by pancreatic beta cells is co-ordinated through the expression and activity of peroxisome proliferator-activated receptors (PPARs). Through their action to lower triacylglycerol delivery to peripheral tissues, PPARalpha activators also oppose insulin resistance by relieving inhibition of insulin-stimulated glucose disposal. Mid to late pregnancy is an insulin-resistant state associated with hypertriglyceridaemia. We investigated regulatory interactions between P...

Activation of PPARalpha pharmacologically by WY14,643 enhances insulin sensitivity in insulin-resistant high-fat-fed rats. PPARalpha is expressed in pancreatic islets, where it affects genes involved in lipid metabolism. We investigated effects of PPARalpha activation by WY14,643 on glucose-stimulated insulin secretion (GSIS) in a rat model of high-fat feeding in which insulin resistance is observed in conjunction with compensatory insulin hypersecretion. To identify persisten...

The renin-angiotensin system (RAS)is important for the regulation of blood pressure with its blockade shown to reduce the vascular complications of diabetes. Adipose tissue expresses the RAS system and may contribute to obesity associated hypertension. Our previous in vitro studies have demonstrated that in human adipose tissue production of both angiotensinogen (AGT) and the active metabolite angiotensin II are stimulated by insulin. The present study investigated the ...

Studies have demonstrated an increased mortality in patients with acromegaly. The major cause of premature death was cardiovascular disease. Cardiovascular mortality was increased in patients with high levels of growth hormone (GH). Somatostatin analogues, such as octreotide, are effective in relieving the symptoms of acromegaly and supressing GH hypersecretion. Long acting preparations, such as Sandostatin-LAR, offer theoretical advantages over SC preparations, such as improv...

Macroprolactin, a high molecular mass complex of prolactin and an IgG antibody is confined to the vasculature and exhibits limited bioactivity in vivo. Using a panel of sera obtained from 10 subjects whose hyperprolactinaemia was due entirely to macroprolactin this study aims to compare the level of detection of macroprolactin by 9 of the most commonly used prolactin immunoassays.The study involved 24 clinical laboratories employing the following 9 anal...