Glucagon is known for its insulin-antagonist effect in the blood glucose homeostasis, while it also reduces vascular resistance. The mechanism of the vasoactive effect of glucagon has not been studied before; thereby we aimed to investigate the mediators involved in the vasodilatation induced by glucagon. The vasoactive effect of glucagon, insulin, and glucagon-like peptide-1 was studied on iso...

Recent studies have established the existence of substrate cycles in humans, but factors regulating the rate of cycling have not been identified. We have therefore investigated the acute response of glucose/glucose-6P-glucose (glucose) and triglyceride/fatty acid (TG/FA) substrate cycling to the infusion of epinephrine (0.03 microgram/kg.min) and glucagon. The response to a high dose glucagon i...

The concentrations of plasma glucose, free fatty acids, insulin, growth hormone, and placental prolactin in subhuman primate fetal and maternal plasma were examined following intravascular administration of insulin and glucagon to the fetus and mother. The neonatal plasma responses to these same stimuli were also examined. Fetal plasma glucose concentrations were minimally altered by direct fet...

Pancreatic glucagon is a 29–amino acid hormone processed from proglucagon by prohormone convertase 2 in the pancreatic a-cells (1). Glucagon’s best-established function is to defend against decreases in glucose availability during fasting, stress, and exercise by stimulating hepatic glycogenolysis phasically and hepatic gluconeogenesis tonically (1–5). Glucagon also increases phasically during ...

Aim: To investigate the effects of ingesting amino acids simultaneously with glucose and fat on postchallenge glycemia lipidemia. Methods: The subjects were eleven healthy young Japanese women (age 21.1 ± 0.1 y). In each session, ingested one three beverages in a randomized crossover design. Materials used an acid mixture (Amizet B™, 0.6 g/kg body weight, 60 mg/kg as acids), (1 weight), cream (...

The close anatomical relationships betaeen pancreatic alpha and beta cells makes possible their interaction at a local (paracrine) level. To demonstrate this in vivo, we have compared the acute glucagon response to intravenous arginine in the basal state and after beta cell suppression by infusions of insulin. The plasma glucose concentration was maintained by the glucose clamp technique. In si...

This paper presents using the fractional PImDn controller module which manipulates insulin infusion rate to maintain normoglycemia in subjects with type 1 diabetes. To prevent severe hypoglycemia, a conventional proportional controller is used to regulate glucagon infusion rate when the blood glucose levels fall below a threshold. Two sets of controller parameters are obtained and evaluated. Fo...

This study was designed to characterize the impact of endurance training on the hepatic response to glucagon. We measured the effect of glucagon on hepatic glucose production (HGP) in resting trained ( n = 8) and untrained ( n = 8) healthy male subjects (maximal rate of O2 consumption: 65.9 ± 1.6 vs. 46.8 ± 0.6 ml O2 ⋅ kg-1 ⋅ min-1, respectively, P < 0.001). Endogenous insulin and glucagon were...

In order to clarify the potential roles of glucagon for energy induction during the perinatal period, the developmental changes of serum glucagon concentration, the ontogenesis of hepatic glucagon receptor and glucagon-sensitive adenylate cyclase system were estimated in comparison with insulin in rats. In fetal rats on day 18 to 20 gestation, serum glucose levels and hepatic glycogen contents ...

To better understand the relationship between the endocrine and exocrine cell types in the Xenopus pancreas, we have cloned the Xenopus amylase cDNA and compared its expression profile with that of four other pancreatic markers: insulin, glucagon, elastase and trypsinogen. Our results demonstrate that the first pancreatic marker to be expressed is insulin, exclusively in the dorsal pancreas. Th...