Related Experiment Video
Updated: Aug 14, 2026

Mixed Primary Cultures of Murine Small Intestine Intended for the Study of Gut Hormone Secretion and Live Cell Imaging of Enteroendocrine Cells
Published on: April 20, 2017
Beta-cell secretory products activate alpha-cell ATP-dependent potassium channels to inhibit glucagon release
Isobel Franklin1, Jesper Gromada, Asllan Gjinovci
1Department of Cell PhysiologyMetabolism, University Medical Centre, 1211 Geneva 4, Switzerland.
Abstract:
Glucagon, secreted from islet alpha-cells, mobilizes liver glucose. During hyperglycemia, glucagon secretion is inhibited by paracrine factors from other islet cells, but in type 1 and type 2 diabetic patients, this suppression is lost. We investigated the effects of beta-cell secretory products zinc and insulin on isolated rat alpha-cells, intact islets, and perfused pancreata. Islet glucagon secretion was markedly zinc sensitive (IC(50) = 2.7 micromol/l) more than insulin release (IC(50) = 10.7 micromol/l). Glucose, the mitochondrial substrate pyruvate, and the ATP-sensitive K(+) channel (K(ATP) channel) inhibitor tolbutamide stimulated isolated alpha-cell electrical activity and glucagon secretion. Zinc opened K(ATP) channels and inhibited both electrical activity and pyruvate (but not arginine)-stimulated glucagon secretion in alpha-cells. Insulin transiently increased K(ATP) channel activity, inhibited electrical activity and glucagon secretion in alpha-cells, and inhibited pancreatic glucagon output. Insulin receptor and K(ATP) channel subunit transcripts were more abundant in alpha- than beta-cells. Transcript for the glucagon-like peptide 1 (GLP-1) receptor was not detected in alpha-cells nor did GLP-1 stimulate alpha-cell glucagon release. beta-Cell secretory products zinc and insulin therefore inhibit glucagon secretion most probably by direct activation of K(ATP) channels, thereby masking an alpha-cell metabolism secretion coupling pathway similar to beta-cells.
Related Concept Videos
Insulin Secretory Vesicles
GPCRs Regulate Adenylyl Cylase Activity
Two...
cAMP-dependent Protein Kinase Pathways
Cells and Secretions of the Pancreas
Exocrine function is carried out by acinar cells, organized into clusters known as acini. These cells contribute to digestion by releasing substantial quantities of enzyme-rich, alkaline digestive juices.
Concurrently, the dispersed clusters of endocrine cells throughout the...
Hormones Regulating Blood Glucose
In addition to accelerating glucose uptake and utilization, insulin has...
Glucose Homeostasis: Pancreatic Islets and Insulin Secretion
Insulin and C-peptide are co-secreted in...

