The endoplasmic reticulum plays a key role in α-cell intracellular Ca²⁺ dynamics and glucose-regulated glucagon secretion in mouse islets.

ABSTRACT: Glucagon is secreted by pancreatic α-cells to counteract hypoglycaemia. How glucose regulates glucagon secretion remains unclear. Here, using mouse islets, we studied the role of transmembrane and endoplasmic reticulum (ER) Ca²⁺ on intrinsic α-cell glucagon secretion. Blocking isradipine-sensitive L-type voltage-gated Ca²⁺ (Ca_v) channels abolished α-cell electrical activity but had little impact on its cytosolic Ca²⁺ oscillations or low-glucose-stimulated glucagon secretion. In contrast, depleting ER Ca²⁺ with cyclopiazonic acid or blocking ER Ca²⁺-releasing ryanodine receptors abolished α-cell glucose sensitivity and low-glucose-stimulated glucagon secretion. ER Ca²⁺ mobilization in α-cells is regulated by intrac

SUBMITTER: Acreman S 

PROVIDER: S-EPMC11033163 | biostudies-literature | 2024 May

REPOSITORIES: biostudies-literature