Amylin, a peptide hormone from pancreatic beta-cells, is reported to inhibit insulin secretion in vitro and in vivo and to inhibit nutrient-stimulated glucagon secretion in vivo. However, it has been reported not to affect arginine-stimulated glucagon secretion in vitro. To resolve if the latter resulted from inactive peptide (a problem in the early literature), those experiments were repeated ...

Despite extensive knowledge of the amino acid composition of beef-pork glucagon, and of the physiologic changes induced by its administration to animals and man, the role of glucagon in the homeostatic regulation of blood glucose level in normal and abnormal states remains to be defined. This fundamental gap in knowledge is the result of the lack of a method sufficiently specific and sensitive ...

The binding of radiolabeled glucagon to rat brain membranes was investigated. Regional distribution studies indicate higher specific binding of 125I-labeled monoiodoglucagon to olfactory tubercule, hippocampus, anterior pituitary, and amygdala membranes, with somewhat lower binding to membranes from septum, medulla, thalamus, olfactory bulb, and hypothalamus. 125I-labeled glucagon bound to rat ...

We characterized two proglucagon cDNAs from the intestine of the sea lamprey Petromyzon marinus. As in other vertebrates, sea lamprey proglucagon genes encode three glucagon-like sequences, glucagon, and glucagon-like peptides 1 and 2 (GLP-1 and GLP-2). This observation indicates that all three glucagon-like sequences encoded by the proglucagon gene originated prior to the divergence of jawed a...

Suppression of pancreatic glucagon secretion by hyperglycemia is a characteristic of normal alpha cell function. However, in diabetic subjects, plasma glucagon is normal or high despite hyperglycemia. It seemed possible that the presence of glucose or its metabolites within the alpha cell might be essential for suppression of glucagon secretion, and that in diabetes an intracellular deficiency ...

We have examined the effects of phospholipase C from Bacillus cereus (Bc) and from Clostridium perfringens (Cp) on various parameters involved in the activity and response of adenylate cyclase to glucagon in rat liver plasma membranes. A crude preparation of Cp-phospholipase C hydrolyzes “neutral” phospholipids (phosphatidylcholine, phosphatidylethanolamine, sphingomyelin) in these membranes. I...

In fasting-refeeding experiments glucagon was found to inhibit the induction of rat liver glucose-6-P dehydrogenase. The kinetics of induction in the presence of glucagon indicated that the hormone decreased the rate of enzyme synthesis without altering the rate of enzyme degradation. Immunochemical titration of the amount of glucose-6-P dehydrogenase protein present in control and glucagon tre...

As a counterregulatory hormone for insulin, glucagon plays a critical role in maintaining glucose homeostasis in vivo in both animals and humans. To increase blood glucose, glucagon promotes hepatic glucose output by increasing glycogenolysis and gluconeogenesis and by decreasing glycogenesis and glycolysis in a concerted fashion via multiple mechanisms. Compared with healthy subjects, diabetic...

OBJECTIVE To minimize hypoglycemia in subjects with type 1 diabetes by automated glucagon delivery in a closed-loop insulin delivery system. RESEARCH DESIGN AND METHODS Adult subjects with type 1 diabetes underwent one closed-loop study with insulin plus placebo and one study with insulin plus glucagon, given at times of impending hypoglycemia. Seven subjects received glucagon using high-gain...

Glucagon, produced by islet α cells, functions to increase blood glucose. Abnormal glucose levels are often seen in cystic fibrosis (CF), a systematic disease caused by mutations of the CF transmembrane conductance regulator (CFTR), and in polycystic ovarian syndrome (PCOS), an endocrine disorder featured with hyperandrogenism affecting 5-10% women of reproductive age. Here, we explored the rol...