Insulin Secretion Depends on Intra-islet Glucagon Signaling

Molecular Mechanism Underlying the Intra-Islet Regulation of Glucagon Secretion

Intra- and inter-islet synchronization of metabolically driven insulin secretion.

Insulin secretion from pancreatic beta-cells is pulsatile with a period of 5-10 min and is believed to be responsible for plasma insulin oscillations with similar frequency. To observe an overall oscillatory insulin profile it is necessary that the insulin secretion from individual beta-cells is synchronized within islets, and that the population of islets is also synchronized. We have recently...

Postprandial suppression of glucagon secretion depends on intact pulsatile insulin secretion: further evidence for the intraislet insulin hypothesis.

Type 2 diabetes is characterized by an approximately 60% loss of beta-cell mass, a marked defect in postprandial insulin secretion, and a failure to suppress postprandial glucagon concentrations. It is possible that postprandial hyperglucagonemia in type 2 diabetes is due to impaired postprandial insulin secretion. To address this, we studied eight adult Goettingen minipigs before and after an ...

Islet Biology/Insulin Secretion

duces proinflammatory lipids that exacerbate β cell dysfunction and death. Inhibition of 12/15-LOX thereby provides a potential therapeutic approach to prevent glycemic deterioration in T1D, but to date no specific inhibitors have been tested T1D. Here we assessed the efficacy and mechanism of a novel and specific 12/15-LOX inhibitor, ML351. Using cultured β cells in vitro, ML351 exhibited no a...

Islet dysfunction in insulin resistance involves impaired insulin secretion and increased glucagon secretion in postmenopausal women with impaired glucose tolerance.

OBJECTIVE To characterize in detail the association between insulin sensitivity and islet function in relation to glucose tolerance in nondiabetic subjects. RESEARCH DESIGN AND METHODS The study included 108 postmenopausal women, aged 57-59 years, with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) and measured glucose tolerance (World Health Organization, 75 g glucose), i...