Endocrine Abstracts

Hyperinsulinism in Infancy (HI) is a potentially-lethal condition of neonates and during early childhood. For many years the pathophysiology of this disorder was unknown. Recent advances in genetics, histopathology and molecule physiology have now revealed the causes of HI in a large cohort of patients. This review focuses upon the relationship between the basis of HI and current treatment options. From defects in ion channel subunit genes to lesions in the control of pancreat...

ATP-evoked signalling events are known to promote release of insulin from pancreatic beta-cells in a Ca2+-dependent manner. In rodent beta-cells and insulin-secreting cell lines, this is mediated by purinergic receptors and there is evidence for the involvement of both P2X and P2Y subtypes. Here,we have used human insulin-secreting cells to examine the expression of purinoceptors in control and disease tissue. Intact islets and isolated beta-cells were obtained from...

Diazoxide is an agonist of ATP sensitive K+ (KATP) channels in beta-cells and is used in the treatment of hyperinsulinism caused by insulinomas or Hyperinsulinism in Infancy (HI). The responsiveness of patients to diazoxide is highly variable and complicated by side-effects which include hypertension and hypertrichosis. The aim of this study was to examine the actions of a novel benzothiadiazine-derivative, BPDZ-154, on beta-cell KATP channels and insulin release. W...

Voltage-gated calcium channels (VGCC) play a fundamental role in the control of insulin secretion from pancreatic B-cells since they govern rises in cytosolic Ca2+ in response to depolarization-dependent agonists, such as glucose. Here, we have examined the function and expression of VGCC in human B-cells. We isolated tissue from patients with B-cell adenoma (AD) and Hyperinsulinism in Infancy (HI) following surgery and used transplantable human islets as controls. ...

Hyperinsulinism in Infancy (HI) is the most common cause of recurrent or persistent hypoglycaemia in early childhood, and manifests as either diffuse abnormalities of pancreatic beta-cell function (Di-HI), or focal adenomatous hyperplasia of beta-cells (Fo-HI). Di-HI is caused by defects in KATP channel genes ABCC8 (SUR1) or KCNJ11 (Kir6.2). Fo-HI arises from somatic loss of maternal heterozygosity resulting in the expression of paternally-derived mutation(s) in SUR1 or Kir6.2...

Introduction: Thyroid hormones act via receptors encoded by different genes (THRA and THRB) generating receptor subtypes (TRα1, TRβ1, TRβ2) with differing, tissue-specific expression. Resistance to Thyroid Hormone due to THRB defects is well recognised, but no THRA mutations have yet been reported. We describe the first case of human TRα-mediated thyroid hormone resistance due to a dominant negative THRA mutation.Results: A 6-year-old...