Arginine vasopressin (AVP) and corticotropin-releasing hormone (CRH) have both been implicated in modulating insulin secretion from pancreatic beta-cells. In the present study, we investigated the insulin-secreting activities of AVP and CRH in wild-type and AVP VIb receptor knockout mice. Both neuropeptides stimulated insulin secretion from isolated mouse pancreatic islets. The response of isle...

Understanding mechanisms by which glibenclamide stimulates insulin release is important particularly given recent promising treatment by glibenclamide of permanent neonatal diabetic subjects. Anti-diabetic sulfonylureas are thought to stimulate insulin secretion solely by inhibiting their high affinity KATP channel receptors at the plasma membrane of β cells. This normally occurs during glucose...

In order to observe the effect of the adrenergic system on pancreatic glucagon secretion in the isolated perfused rat pancreas, phenylephrine, an alpha-adrenergic agonist, and isoproterenol, a beta-adrenergic agonist, were added to the perfused solution. 1.2 microM phenylephrine suppressed glucagon secretion at 2.8 mM glucose, and it also decreased insulin secretion at 11.1 mM glucose. 240 nM i...

The profile of insulin secretion and the role of proinsulin processing across the spectrum of glucose tolerance in obese youth have not been studied. The aims of this study were to define the role of insulin secretion and proinsulin processing in glucose regulation in obese youth. We performed hyperglycemic clamps to assess insulin secretion, applying a model of glucose-stimulated insulin secre...

Diabetes Mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. The basis of the abnormalities in carbohydrate, fat, and protein metabolism in diabetes is deficient action of insulin on target tissues. Deficient insulin action results from inadequate insulin secretion and/ or diminished tissue responses...

The hyperbolic relationship between insulin secretion and sensitivity has been used to assess in vivo b-cell function (i.e., the disposition index). The disposition index emphasizes the importance of taking into account both skeletal muscle and hepatic insulin resistance to depict insulin secretion. However, we propose that adipose tissue insulin resistance also needs to be accounted for when c...

To define the roles of circadian rhythmicity (intrinsic effects of time of day independent of the sleep or wake condition) and sleep (intrinsic effects of the sleep condition, irrespective of the time of day) on the 24-h variation in glucose tolerance, eight normal men were studied during constant glucose infusion for a total of 53 h. The period of study included 8 h of nocturnal sleep, 28 h of...

Understanding mechanisms by which glibenclamide stimulates insulin release is important, particularly given recent promising treatment by glibenclamide of permanent neonatal diabetic subjects. Antidiabetic sulfonylureas are thought to stimulate insulin secretion solely by inhibiting their high-affinity ATP-sensitive potassium (K(ATP)) channel receptors at the plasma membrane of beta-cells. This...

................................................................................4 BACKGROUND..........................................................................5 §1.0. Glucose Homeostasis......................................................................5 1.1. Pancreatic beta-cells..............................................................5 1.2.Insulin..................................

Statins are widely used in the treatment of hypercholesterolemia and are efficient in the prevention of cardiovascular disease. Molecular mechanisms explaining statin-induced impairment in insulin secretion remain largely unknown. In the current study, we show that simvastatin decreased glucose-stimulated insulin secretion in mouse pancreatic MIN6 β-cells by 59% and 79% (p<0.01) at glucose conc...