Physiological and Pathophysiological Control of Glucagon Secretion by Pancreatic α-Cells

Gilon, Patrick; Cheng-Xue, Rui; Lai, Bao Khanh; Chae, Heeyoung; Ruiz, Ana Gomez

doi:10.1007/978-94-007-6884-0_37-2

Cited by 3 publications

(1 citation statement)

References 477 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, to fully define the interaction matrix K σσ , one needs to define the signs for the autocrine interactions of A αα , A ββ , and A δδ , as well as the previously defined six paracrine interactions (table 1). Glucagon and glutamate, secreted by α cells, potentiate glucagon synthesis and secretion [120][121][122][123], which implies a positive autocrine interaction ( A αα = 1). Similarly insulin, serotonin, GABA, and ATP, secreted by β cells, stimulate insulin secretion [126,127,129,130,137], which also implies a positive autocrine interaction (A ββ = 1).…”

Section: Intra-islet Networkmentioning

confidence: 99%

Tripartite cell networks for glucose homeostasis

Song

2019

Phys. Biol.

View full text Add to dashboard Cite

Controlling the excess and shortage of energy is a fundamental task for living organisms. Diabetes is a representative metabolic disease caused by the malfunction of energy homeostasis. The islets of Langerhans in the pancreas release long-range messengers, hormones, into the blood to regulate the homeostasis of the primary energy fuel, glucose. The hormone and glucose levels in the blood show rhythmic oscillations with a characteristic period of 5-10 min, and the functional roles of the oscillations are not clear. Each islet has α and β cells that secrete glucagon and insulin, respectively. These two counter-regulatory hormones appear sufficient to increase and decrease glucose levels. However, pancreatic islets have a third cell type, δ cells, which secrete somatostatin. The three cell populations have a unique spatial organization in islets, and they interact to perturb their hormone secretions. The mini-organs of islets are scattered throughout the exocrine pancreas. Considering that the human pancreas contains approximately a million islets, the coordination of hormone secretion from the multiple sources of islets and cells within the islets should have a significant effect on human physiology. In this review, we introduce the hierarchical organization of tripartite cell networks, and recent biophysical modeling to systematically understand the oscillations and interactions of α, β, and δ cells. Furthermore, we discuss the functional roles and clinical implications of hormonal oscillations and their phase coordination for the diagnosis of type II diabetes.

show abstract

Section: Intra-islet Networkmentioning

confidence: 99%

Tripartite cell networks for glucose homeostasis

Song

2019

Phys. Biol.

View full text Add to dashboard Cite

show abstract

Fructose, glucose and fat interrelationships with metabolic pathway regulation and effects on the gut microbiota

Szabó

Maróti

Solymosi

et al. 2021

AVet

View full text Add to dashboard Cite

The purpose of this 30-day feeding study was to elucidate the changes, correlations, and mechanisms caused by the replacement of the starch content of the AIN-93G diet (St) with glucose (G), fructose (F) or lard (L) in body and organ weights, metabolic changes and caecal microbiota composition in rats (Wistar, SPF). The body weight gain of rats on the F diet was 12% less (P = 0.12) than in the St group. Rats on the L diet consumed 18.6% less feed, 31% more energy and gained 58.4% more than the animals on the St diet, indicating that, in addition to higher energy intake, better feed utilisation is a key factor in the obesogenic effect of diets of high nutrient and energy density. The G, F and L diets significantly increased the lipid content of the liver (St: 7.01 ± 1.48; G: 14.53 ± 8.77; F: 16.73 ± 8.77; L: 19.86 ± 4.92% of DM), suggesting that lipid accumulation in the liver is not a fructose-specific process. Relative to the St control, specific glucose effects were the decreasing serum glucagon (–41%) concentrations and glucagon/leptin ratio and the increasing serum leptin concentrations (+26%); specific fructose effects were the increased weights of the kidney, spleen, epididymal fat and the decreased weight of retroperitoneal fat and the lower immune response, as well as the increased insulin (+26%), glucagon (+26%) and decreased leptin (–25%) levels. This suggests a mild insulin resistance and catabolic metabolism in F rats. Specific lard effects were the decreased insulin (–9.14%) and increased glucagon (+40.44%) and leptin (+44.92%) levels. Relative to St, all diets increased the operational taxonomic units of the phylum Bacteroidetes. G and L decreased, while F increased the proportion of Firmicutes. F and L diets decreased the proportions of Actinobacteria, Proteobacteria and Verrucomicrobia. Correlation and centrality analyses were conducted to ascertain the positive and negative correlations and relative weights of the 32 parameters studied in the metabolic network. These correlations and the underlying potential mechanisms are discussed.

show abstract

Effect of Macronutrient on Plasma, Liver and Pancreatic Metabolomics and their Hierarchic Weights in the Metabolic Network

Szabó¹,

Bruckner²,

Korányi³

et al. 2018

TONUTRJ

View full text Add to dashboard Cite

Background/Aims:The aims of this study were to: 1) investigate the specific metabolomic effects of single macro nutrients in cold exposed rats; and 2) Using centrality analysis ascertain the correlations between these metabolomic parameter measurements.Methods:Fifty male Wistar rats were divided into 5 groups and individually housed under cold climatic conditions. Rats were either cold exposed fasted (negative control) or fed with the following commercially available single macronutrients: casein, POLYCOSE® and safflower oil; the positive control diets included all macronutrients. Samples from the plasma, liver and pancreas were collected and 33 different parameters were determined.Results:The primary correlation found between pancreatic hormones and the variables as measured, showed significant positive connections between centrality network node members. Heatmap analysis showed that the macronutrients fed have very differing effects on the metabolomics measured,i.e.casein has a high Heatmap Index on plasma corticosterone while POLYCOSE® and fat had a minimal impact.Conclusion:The cold exposed fasted animal model, in which nutrient catabolism is near maximal, serves as a useful “in vivo” tool for studying the relationships among the nutrients, hormones and digestive enzymes under cold stress conditions; feed intake, liver glucose, and small intestinal amylase hold a high position in centrality mapping and are highly imbedded in the metabolomic networks. For example, this model shed light on the relations amoung hormone and enzyme contents of duodenal pancreas, gastric+splenic pancreas and enzyme activities in small intestinal contents. These findings can be applied to optimizing feeding of animals under cold stress.

show abstract

Physiological and Pathophysiological Control of Glucagon Secretion by Pancreatic α-Cells

Cited by 3 publications

References 477 publications

Tripartite cell networks for glucose homeostasis

Tripartite cell networks for glucose homeostasis

Fructose, glucose and fat interrelationships with metabolic pathway regulation and effects on the gut microbiota

Effect of Macronutrient on Plasma, Liver and Pancreatic Metabolomics and their Hierarchic Weights in the Metabolic Network

Contact Info

Product

Resources

About