α細胞ミトコンドリアホスホエノールピルビン酸サイクルによるアミノ酸センシングは、グルカゴン分泌に影響を与えることなく細胞内Ca2+レベルを調節する
関連する実験動画
Updated: Jan 13, 2026

Imaging Calcium Dynamics in Subpopulations of Mouse Pancreatic Islet Cells
Published on: November 26, 2019
Erli Jin1, Hannah R Foster1,2, Evgeniy Potapenko1,2
1Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI.
Article Highlights:
Our studies identify a role for the α-cell phosphoenolpyruvate cycle in sensing amino acids under hypoglycemic conditions. Leucine, in the presence of glutamine, opposes alanine/arginine-stimulated Ca2+ influx and glucagon secretion. Pyruvate kinase and phosphoenolpyruvate carboxykinase 2 are required for leucine to close α-cell KATP channels and limit Ca2+ influx. All of the amino acids tested regulate glucagon secretion, but none do so by modulating membrane depolarization or intracellular Ca2+ levels.
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