Radioimmunoassays of glucagon in plasma may be complicated by interaction with other substances of high molecular mass. Precipitates of such substances with ammonium sulfate showed, after isoelectric focusing, two fractions having glucagon immunoreactivity. One fraction (pl approximately 10) evidently is associated with the Fc portion (but not the Fab portion) of purified polyclonal immunoglobu...

High-protein feeding acutely lowers postprandial glucose concentration compared to low-protein feeding, despite a dichotomous rise of circulating glucagon levels. The physiological role of this glucagon rise has been largely overlooked. We here first report that glucagon signalling in the dorsal vagal complex (DVC) of the brain is sufficient to lower glucose production by activating a Gcgr-PKA-...

We have studied the effect of glucagon on the expression of a triiodothyronine (T3) and carbohydrate-inducible mRNA sequence (mRNA-S14) in rat liver that undergoes a threefold diurnal variation (peak, 2200 h; nadir, 0800 h). Glucagon injection into euthyroid rats (25 micrograms/100 g body wt i.p., three doses at 15-min intervals) during the nocturnal plateau of mRNA-S14 caused a monoexponential...

Liver parenchymal cells were isolated from adult rats and cultured in collagen-coated plastic petri dishes in serum-free medium. Glucagon induced 4- to 5-fold increases in alpha-aminoisobutyric acid (AIB) transport within 6 hr. Dexaemthasone had no direct effect on AIB transport but greatly potentiated the induction by glucagon ("permissive effect"). Levels of 3':5'-cyclic AMP increased 30- to ...

After hepatectomy patients with cirrhosis and liver cancer may develop progressive hepatic dysfunction and eventually hepatic failure. Insulin and glucagon are often used to treat certain kinds of hepatic dysfunction and hepatic insufficiency. We investigated the effect of glucagon on bile acid metabolism and pancreatic endocrine function. In 7 patients with severe cirrhosis and cancer of the l...

Increased levels of glucagon in type 2 diabetes are well known and, until now, have been considered deleterious. However, glucagon has an important role in the maintenance of both heart and kidney function. Moreover, in the past, glucagon has been therapeutically used for heart failure treatment. The new antidiabetic drugs, dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter-2 i...

Glucagon stimulates 14CO2 production from [1-14C] glycine by isolated rat hepatocytes. Maximal stimulation (70%) of decarboxylation of glycine by hepatocytes was achieved when the concentration of glucagon in the medium reached 10 nM; half-maximal stimulation occurred at a concentration of about 2 nM. A lag period of 10 min was observed before the stimulation could be measured. Inclusion of bet...

The effects of glucagon on atrioventricular nodal automaticity and ventricular automaticity were studied in anesthetized open-chest dogs. After the sinoatrial node was crushed, glucagon, 4 fig/kg, produced a marked and sustained increase in the rate of A-V nodal discharge (27.6 ± 10.1 vs. 117.4 ± 6.5 beats/min) that persisted for an average of 20 minutes. The effect of glucagon was not modified...

The effects of glucagon, 50 |iig/kg, on atrioventricular (A-V) conduction and ventricular automaticity were studied in 14 dogs. Atrial pacing was used to control the heart rate. The His bundle electrogram was recorded, and the interval from the pacing impulse (P) to the His bundle spike (H), the P-H interval, was used as a measure of A-V conduction. Ventricular automaticity was estimated in fou...

Prostaglandins, released from Kupffer cells, have been shown to mediate the increase in hepatic glycogenolysis by various stimuli such as zymosan, endotoxin, immune complexes, and anaphylotoxin C3a involving prostaglandin (PG) receptors coupled to phospholipase C via a G(0) protein. PGs also decreased glucagon-stimulated glycogenolysis in hepatocytes by a different signal chain involving PGE2 r...